More distance per Calorie: Walk vrs Granny Gear Uphill?

[Artemisia]

Peter Clinch wrote:

> I recall one incident when a pal and I were taking our MTBs up a fairly
> steep grassy field. I got bored at walking pace, and decided I'd walk.
> While walking, I soon overtook my pal, still spinning happily in 1st...


So isn't it actually more efficient energy use to walk uphill than to
pedal, even if you do have unimaginably low gears and no topple-over on
a trike?

I'm thinking perhaps the only advantage of trying to pedal up my hills
is the inconvenience of trying to stand up out of a recumbent...

EFR
Ile de France

[A.Lee]

Artemisia > wrote:

> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?

I would think that cycling up would be less efficient.
In both cases, you need to get the same weight up the same
height/distance.
The cycle will not be 100% efficient in transferring power to the
wheels.However, there may be a slight advantage with the very low
rolling resistance, compared to friction of the feet/tarmac interface.
Maybe not.
The legs walking up will be a lot more efficient in tranferring the
power to make forward progress, so I'd assume walking would be the most
energy efficient way.
Over to the physicists.
Alan.

--
To reply by e-mail, change the ' + ' to 'plus'.

[Tony Raven[_2_]]

Artemisia > wrote in
:
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over
> on a trike?
>
> I'm thinking perhaps the only advantage of trying to pedal up my hills
> is the inconvenience of trying to stand up out of a recumbent...
>

Cycling is a more efficient way of moving than walking so cycling up will
use less energy

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Artemisia]

Tony Raven wrote:

> Cycling is a more efficient way of moving than walking so cycling up will
> use less energy

Is cycling more efficient than walking under all circumstances? Are you
speaking from experience?

EFR
Ile de France

[Martin Dann]

Artemisia wrote:
> Tony Raven wrote:
>
>> Cycling is a more efficient way of moving than walking so cycling up
>> will use less energy
>
> Is cycling more efficient than walking under all circumstances? Are you
> speaking from experience?

Just a quick guess here, but is cycling up a 45degree
slope similarly efficient to running up a 45 degree flight
of stairs at the same speed?
(for a weightless bike).

Martin.

[Roger Zoul]

Martin Dann wrote:
:: Artemisia wrote:
::: Tony Raven wrote:
:::
:::: Cycling is a more efficient way of moving than walking so cycling
:::: up will use less energy
:::
::: Is cycling more efficient than walking under all circumstances? Are
::: you speaking from experience?
::
:: Just a quick guess here, but is cycling up a 45degree
:: slope similarly efficient to running up a 45 degree flight
:: of stairs at the same speed?
:: (for a weightless bike).
::
:: Martin.

Can one cycle up a 45 degree slope? Isn't that 100% grade?

[Tony Raven[_2_]]

Artemisia > wrote in
:

> Tony Raven wrote:
>
>> Cycling is a more efficient way of moving than walking so cycling up
>> will use less energy
>
> Is cycling more efficient than walking under all circumstances? Are
> you speaking from experience?
>

No I'm speaking from the research evidence. Walking takes about 40% more
calories per mile than cycling for commuting and the difference can be much
more. If you had a really heavy bike it might equal things out a bit on a
hill but it would have to be really heavy.
http://ffden-2.phys.uaf.edu/211.fall2000.web.projects/J%
20Krizek/humanpower%20page%203.html

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Artemisia[_2_]]

On 7 sep, 00:28, Martin Dann > wrote:

> Just a quick guess here, but is cycling up a 45degree
> slope similarly efficient to running up a 45 degree flight
> of stairs at the same speed?
> (for a weightless bike).

Why running?

EFR
Ile de France

[Artemisia[_2_]]

On 7 sep, 02:17, "Roger Zoul" > wrote:

> Can one cycle up a 45 degree slope? Isn't that 100% grade?

Well if it can't even be done, then it can't be as efficient, can it?

EFR
Ile de France

[[email protected]]

On Sep 7, 2:38 pm, Tony Raven > wrote:
> Artemisia > wrote :
>
> > Tony Raven wrote:
>
> >> Cycling is a more efficient way of moving than walking so cycling up
> >> will use less energy
>
> > Is cycling more efficient than walking under all circumstances? Are
> > you speaking from experience?
>
> No I'm speaking from the research evidence. Walking takes about 40% more
> calories per mile than cycling for commuting and the difference can be much
> more. If you had a really heavy bike it might equal things out a bit on a
> hill but it would have to be really heavy.http://ffden-2.phys.uaf.edu/211.fall2000.web.projects/J%
> 20Krizek/humanpower%20page%203.html

But you are assuming that the "research evidence" about general
cycling (including level and downhill riding) also applies to the
specific case of cycling up a steep hill. Clearly there are such large
and fundamental differences in the physics that this hypothesis is at
best...a hypothesis. It's not an implausible null hypothesis when the
slope is reasonably shallow and the surface firm, but I don't see any
reasonable basis for it in steep and soft conditions (and anecdotal
evidence suggests it is wrong).

In soft mud (or sand, see below) there is no question that cycling can
be harder work, even on the level. Again, that is exactly as expected
from simple physical principles.

http://www.japanprobe.com/?p=2585

James

[[email protected]]

On 6 Sep, 18:09, Artemisia > wrote:
> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?

According to wikipedia:

"On firm, flat, ground, a 70 kg man requires about 100 watts to walk
at 5 km/h. That same man on a bicycle, on the same ground, with the
same power output, can average 25 km/h, so energy expenditure in terms
of kcal/kg/km is roughly one-fifth as much."

http://en.wikipedia.org/wiki/Bicycle_performance

I've found other references on the same lines that suggest that
calories per hour for cycling and walking are about the same. [1] One
said walking used 25% more; this site

http://www.coolnurse.com/calories.htm

suggests that per minute, cycling uses more calories than walking. It
also says the difference is greater if you weigh more. Comparing
walking at 4 mph and cycling at 10 mph, if you weigh around 110 lbs
you will use 20% more calories cycling than walking, but at 190 lbs,
cycling will use over twice as many calories per minute. [3] It would
still be more efficient per mile than walking, because you are
travelling 2.5 times as fast, but the difference is quite small.

Anyway, coming back to the original question and for simplicity,
taking the (never known to be wrong ;-) wikipedia figure of cycling
and walking using the same number of calories per minute: the answer
is then simple, the most efficient method is the one that gets you up
the hill quickest. If you think you will be quicker walking than
cycling and want to save energy, get off and walk (if you want to lose
weight, stay on and pedal). Peter almost certainly used less calories
getting up the hill than his spinning friend.

Rob

[1] These comparisons are only valid at moderate cycling speeds - as
you go faster more of your energy goes in to overcoming wind
resistance - according to this calculator [2], to increase your speed
from 15 mph to 27 mph, you have to increase your power output from 100
W to 500 W.

[2] http://austinimage.com/bp/velocity/velocity.html

[3] Personally I find the steep increase in calorie requirement for
increasing weight suggested by this site rather difficult to believe.
The heavier person will use significantly more energy accelerating to
10 mph, but that's a one off. They will presumably be bigger and so
have slighly more air resistance to overcome and slightly greater
friction losses, but I can't see how those would add up to such a huge
increase in calorie consumption.

[Nick Kew]

On Thu, 06 Sep 2007 19:09:41 +0200
Artemisia > wrote:

> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a
> > fairly steep grassy field. I got bored at walking pace, and
> > decided I'd walk. While walking, I soon overtook my pal, still
> > spinning happily in 1st...

A rest is as good as ... using different muscles?

> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over
> on a trike?

The inefficiency of walking is the energy you (irretrievably) lose
when the centre of gravity of the body moves up&down every step.
That's the fundamental reason cycling is more efficient.

If cycling loses a lot of energy - e.g. onna rocky or dusty trail -
it can lose its advantage. Somewhere before becoming impossible,
it becomes b***** hard work!

I recollect a coupla years ago thinking on this after I cycling up
a local tor. I passed through a local car park, where a pair of
walkers were setting out on the same route, same time as me, and
(I think) about the same pace as I'd have done if walking briskly.
Left them way behind on the easy grass slope. Higher up, on rougher
ground, they were gaining on me, and we reached the top at the same
time. I thought that said something about cycling vs walking.

--
not me guv

[Roger Merriman]

Tony Raven > wrote:

> Artemisia > wrote in
> :
> >
> > So isn't it actually more efficient energy use to walk uphill than to
> > pedal, even if you do have unimaginably low gears and no topple-over
> > on a trike?
> >
> > I'm thinking perhaps the only advantage of trying to pedal up my hills
> > is the inconvenience of trying to stand up out of a recumbent...
> >
>
> Cycling is a more efficient way of moving than walking so cycling up will
> use less energy

not sure about that given a steep enought gradient. certinaly some hills
are easyer to walk up or push a bike than ride up it. one of the hills
nr my folks place is like that, this said it's not equal at 30-35% you
spend a fair effort keeping the weight right, and even riding slowly up
in a 20inch gear you are faster than you'd walk up, not by much it has
to be said. mind you plenty wouldn't want to walk up let alone bike up
it.

cars have failed to get up it. and few years back some some american
OAP's had a terrifing ride down it in a bus. luckly for them there is a
chicane in the middle as by that point, the brakes, gears, engine etc
had all burnt out....

roger
--
www.rogermerriman.com

[Tony Raven[_2_]]

" > wrote in
oups.com:

> On Sep 7, 2:38 pm, Tony Raven > wrote:
>> Artemisia > wrote
>> :
>>
>> > Tony Raven wrote:
>>
>> >> Cycling is a more efficient way of moving than walking so cycling
>> >> up will use less energy
>>
>> > Is cycling more efficient than walking under all circumstances? Are
>> > you speaking from experience?
>>
>> No I'm speaking from the research evidence. Walking takes about 40%
>> more calories per mile than cycling for commuting and the difference
>> can be much more. If you had a really heavy bike it might equal
>> things out a bit on a hill but it would have to be really
>> heavy.http://ffden-2.phys.uaf.edu/211.fall2000.web.projects/J%
>> 20Krizek/humanpower%20page%203.html
>
> But you are assuming that the "research evidence" about general
> cycling (including level and downhill riding) also applies to the
> specific case of cycling up a steep hill. Clearly there are such large
> and fundamental differences in the physics that this hypothesis is at
> best...a hypothesis. It's not an implausible null hypothesis when the
> slope is reasonably shallow and the surface firm, but I don't see any
> reasonable basis for it in steep and soft conditions (and anecdotal
> evidence suggests it is wrong).
>
> In soft mud (or sand, see below) there is no question that cycling can
> be harder work, even on the level. Again, that is exactly as expected
> from simple physical principles.
>
> http://www.japanprobe.com/?p=2585
>



Yes I am sure you can come up with all sorts of scenarios - boulder
fields, scree slopes, deep snow, overhanging rock faces.... where cycling
is less efficient than walking but that was not the tenor of the original
question not did I feel it necessary to caveat every possibility in my
original reply. But please feel free to point out my omissions.

Meanwhile perhaps you could elucidate for us what the "large and
fundamental differences in the physics" (other than the weight of the
bike) are and why the angle of a typical road surface should reverse the
efficiency relationship between cycling and walking. Reference should be
made to the equation

W = kr.Ms + ka.A.s.v2 + g.sin i.Ms

where W is power, kr is the rolling resistance coefficient, M is the
combined mass of cyclist and bicycle, s is the bicycle speed on the road,
ka is the air resistance coefficient, A is the combined frontal area of
cyclist and bicycle, v is the bicycle speed through the air (i.e. road
speed plus head wind speed), g is the gravitational acceleration
constant, and i is the road angle (DiPrampero PE, Cortili P, Mognoni P,
Saibene F (1979). Equation of motion of a cyclist. Journal of Applied
Physiology 47, 201-206)

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tony Raven[_2_]]

wrote in news:1189153311.747067.116280@
22g2000hsm.googlegroups.com:

> On 6 Sep, 18:09, Artemisia > wrote:
>> [...]
>
> According to wikipedia:
>
> "On firm, flat, ground, a 70 kg man requires about 100 watts to walk
> at 5 km/h. That same man on a bicycle, on the same ground, with the
> same power output, can average 25 km/h, so energy expenditure in terms
> of kcal/kg/km is roughly one-fifth as much."
>
> http://en.wikipedia.org/wiki/Bicycle_performance
>
> I've found other references on the same lines that suggest that
> calories per hour for cycling and walking are about the same. [1] One
> said walking used 25% more; this site
>
> http://www.coolnurse.com/calories.htm
>
> suggests that per minute, cycling uses more calories than walking. It
> also says the difference is greater if you weigh more.

The reference to use is The Compendium of Physical Activities which can be
downloaded from http://prevention.sph.sc.edu/tools/compendium.htm. This
uses METs which are 1 kcal/kg/hr so you have to multiply by your weight and
normalise for speed to get the answer. Walking is about 3.0 METs and
cycling 4-8 but the cycling speed means per mile cycling wins big time
while per hour walking wins (although you don't go nearly as far).


--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Peter Clinch]

Artemisia wrote:
> Peter Clinch wrote:
>
>> I recall one incident when a pal and I were taking our MTBs up a fairly
>> steep grassy field. I got bored at walking pace, and decided I'd walk.
>> While walking, I soon overtook my pal, still spinning happily in 1st...
>
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?

You need to be very careful with what the terms mean. "Efficiency" can
mean all sorts of things but it'll typically be which uses least energy.
And cycling will very, very probably use less energy *but* that's not
all there is to it... You have to take into account stuff like your
cycling muscles may well be past their best (because you've just done
75% of a bloody great hill) and a change can be as good as a rest.

> I'm thinking perhaps the only advantage of trying to pedal up my hills
> is the inconvenience of trying to stand up out of a recumbent...

No, it'll generally be better, but there will be times when you just
/can't/ keep up the pedalling (can be tiredness, maybe you just be
bothered any more) and a short walk to top out is the easiest way to
finish the job, if not in absolute energy terms but which feels
subjectively best for your body at the time.

Try not to think in such black and white terms. Cycling and walking
have their places and there are lots of interlocking variables that
determine which is right at the time: how tired you are, how much of a
hurry you're in, how big is the particular hill, how hot is the day etc.
etc.

In the example this sub-thread spins out from I could have finished the
job on the bike and would probably have used less net energy. But I
just couldn't be /bothered/ with it any more.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Alan Braggins]

In article >, Tony Raven wrote:
>The reference to use is The Compendium of Physical Activities which can be
>downloaded from http://prevention.sph.sc.edu/tools/compendium.htm. This
>uses METs which are 1 kcal/kg/hr so you have to multiply by your weight and
>normalise for speed to get the answer. Walking is about 3.0 METs and
>cycling 4-8 but the cycling speed means per mile cycling wins big time
>while per hour walking wins (although you don't go nearly as far).

Except the question was in response to a scenario where Pete walking
his bike had overtaken his friend riding in the lowest available gear.
We all know cycling is more efficient in general, the question was whether
that's still true on steep uneven ground where walking may be quicker.

[Tony Raven[_2_]]

(Alan Braggins) wrote in
:

> In article >, Tony Raven wrote:
>>The reference to use is The Compendium of Physical Activities which
>>can be downloaded from
>>http://prevention.sph.sc.edu/tools/compendium.htm. This uses METs
>>which are 1 kcal/kg/hr so you have to multiply by your weight and
>>normalise for speed to get the answer. Walking is about 3.0 METs and
>>cycling 4-8 but the cycling speed means per mile cycling wins big time
>>while per hour walking wins (although you don't go nearly as far).
>
> Except the question was in response to a scenario where Pete walking
> his bike had overtaken his friend riding in the lowest available gear.
> We all know cycling is more efficient in general, the question was
> whether that's still true on steep uneven ground where walking may be
> quicker.
>

Efficiency is normally taken as the energy needed to travel a distance, not
speed otherwise a Hummer would be classed as more efficient than a bicycle.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Peter Clinch]

Tony Raven wrote:

> Efficiency is normally taken as the energy needed to travel a distance, not
> speed otherwise a Hummer would be classed as more efficient than a bicycle.

I think that's already been accepted and understood here. The point is
that when you throw rough ground into the equation there is a lot of
inefficiency thrown in to the cycling because the bike and rider has to
spend a lot of power moving up and down as well as along (why a full sus
bike is faster downhill with the gravitational acceleration than a
rigid, but it doesn't work so well when climbing at very low speed).

The question is, is that up-and-down loss of efficiency bigger than the
inherent inefficiency of walking. Since this was a grass field which
isn't all that /rough/, I would suspect not in this case, but OTOH the
grass gives a lot more friction to a constantly contacting bike wheel
than a walker's feet which are typically above it for almost the whole time.

I don't know. I suspect it's not the straightforward answer of a smooth
road though (but on that smooth road again the messy Real World caveat
that you can only burn energy at /any/ efficiency if the relevant
muscles are still up to it, and if your cycling muscles are knackered
and the walking ones aren't that could be a moot point).

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[[email protected]]

On Sep 7, 6:33 pm, Tony Raven > wrote:
> " > wrote groups.com:
>
>
>
> > On Sep 7, 2:38 pm, Tony Raven > wrote:
> >> Artemisia > wrote
> >> :
>
> >> > Tony Raven wrote:
>
> >> >> Cycling is a more efficient way of moving than walking so cycling
> >> >> up will use less energy
>
> >> > Is cycling more efficient than walking under all circumstances? Are
> >> > you speaking from experience?
>
> >> No I'm speaking from the research evidence. Walking takes about 40%
> >> more calories per mile than cycling for commuting and the difference
> >> can be much more. If you had a really heavy bike it might equal
> >> things out a bit on a hill but it would have to be really
> >> heavy.http://ffden-2.phys.uaf.edu/211.fall2000.web.projects/J%
> >> 20Krizek/humanpower%20page%203.html
>
> > But you are assuming that the "research evidence" about general
> > cycling (including level and downhill riding) also applies to the
> > specific case of cycling up a steep hill. Clearly there are such large
> > and fundamental differences in the physics that this hypothesis is at
> > best...a hypothesis. It's not an implausible null hypothesis when the
> > slope is reasonably shallow and the surface firm, but I don't see any
> > reasonable basis for it in steep and soft conditions (and anecdotal
> > evidence suggests it is wrong).
>
> > In soft mud (or sand, see below) there is no question that cycling can
> > be harder work, even on the level. Again, that is exactly as expected
> > from simple physical principles.
>
> >http://www.japanprobe.com/?p=2585
>
> Yes I am sure you can come up with all sorts of scenarios - boulder
> fields, scree slopes, deep snow, overhanging rock faces.... where cycling
> is less efficient than walking but that was not the tenor of the original
> question not did I feel it necessary to caveat every possibility in my
> original reply. But please feel free to point out my omissions.

The first obvious omission is the weight of the bicycle (as you admit
below) which is a significant penalty for the cyclist, and the second
one is the possible softness of the ground which on a grassy field
where a walker overtakes a cyclist seems hard to ignore!

>
> Meanwhile perhaps you could elucidate for us what the "large and
> fundamental differences in the physics" (other than the weight of the
> bike) are and why the angle of a typical road surface should reverse the
> efficiency relationship between cycling and walking.

as I've mentioned, the original poster was specifically talking about
off-road cycling. I repeat here for your edification:
---
On Sep 7, 2:09 am, Artemisia > wrote:
> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?
---

I really find it hard to believe that an intelligent and experienced
off-road cyclist could seriously dispute that in the situation as
described, it may indeed be more energy efficient to walk.

James

[Clive George]

"Artemisia" > wrote in message
...
> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on a
> trike?
>
> I'm thinking perhaps the only advantage of trying to pedal up my hills is
> the inconvenience of trying to stand up out of a recumbent...

You're on-road on your trike, which is a bit of a different place.

But more importantly with the trike you've got something you can't do on any
bike : stop and sit there. So you pedal until you're puffed, put the brakes
on (with locking device/velcro as appropriate) and sit there relaxing, coz
you can.

(And pushing a recumbent trike uphill is liable to be extremely tedious too)

cheers,
clive

[Tony Raven[_2_]]

Peter Clinch > wrote in
:
>
> I think that's already been accepted and understood here.

Apparently not as Alan clearly said "We all know cycling is more
efficient in general, the question was whether
that's still true on steep uneven ground where walking may be quicker."

> The point
> is that when you throw rough ground into the equation there is a lot
> of inefficiency thrown in to the cycling because the bike and rider
> has to spend a lot of power moving up and down as well as along (why a
> full sus bike is faster downhill with the gravitational acceleration
> than a rigid, but it doesn't work so well when climbing at very low
> speed).
>
> The question is, is that up-and-down loss of efficiency bigger than
> the inherent inefficiency of walking. Since this was a grass field
> which isn't all that /rough/, I would suspect not in this case, but
> OTOH the grass gives a lot more friction to a constantly contacting
> bike wheel than a walker's feet which are typically above it for
> almost the whole time.
>
> I don't know. I suspect it's not the straightforward answer of a
> smooth
> road though (but on that smooth road again the messy Real World
> caveat
> that you can only burn energy at /any/ efficiency if the relevant
> muscles are still up to it, and if your cycling muscles are knackered
> and the walking ones aren't that could be a moot point).

But I doubt that rough grassy fields are relevant to Artemesia's original
question. Yes there are lots of ways you can make the bike less
efficient - throw in steps or a scree slope for example - but generally
none relevant to the originally posed question.

As for tired muscles, the evidence is that the efficiency does not
change, the muscles just get limited in the energy throughput, consuming
less energy and putting out less energy.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[[email protected]]

On Sep 6, 7:09 pm, Artemisia > wrote:
> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?
>
> I'm thinking perhaps the only advantage of trying to pedal up my hills
> is the inconvenience of trying to stand up out of a recumbent...
>
> EFR
> Ile de France

Cycling (particularly on a recumbent!) is not a weight bearing
exercise like walking. That is to say, cycling up a hill requires you
to only move your center of mass up the slope, not carry it. When you
carry something up a hill you need to not only move it up the slope,
you need to support it's weight the whole time too. Think about
carrying rocks up a hill with a wheelbarrow vs a backpack. When
cycling the center of mass stays pretty still and thus follows the
slope of the hill without too much extra energy spent. Walking makes
the center of mass bob up and down a bit which uses energy that
cycling doesn't. Cycling has the added weight of the bike, and the
resistance of the drivetrain, rolling resistance, and wind resistance,
but in terms of calories per distance at slow speeds where wind and
rolling resistance are minimal, cycling will always be more efficient.
At high speeds where the exponential wind resistance is much greater,
one needs to expend a lot more energy to overcome this resistance, and
then walking is more efficient in terms of calories per distance. A
lot slower too!

Now in the case of a steep hill with grass and thus relatively high
rolling resistance, it may be that the increased rolling resistance
more than makes up for the difference of cycling not being a weight
bearing exercise. Gearing and what is a comfortable range of cadence
and force generation for the leg muscles comes into play too.

If you try pushing someone on a bike on a flat feild of grass you can
see how much resistance there is. And since it seems that riding up
this hill vs walking was more or less a wash despite the extra rolling
resistance, this suggests to me that cycling is that much easier than
walking by the same amount of effort it took to push the person on the
grass. (That made sense to me at least...)

Joseph

[Peter Clinch]

wrote:

> I really find it hard to believe that an intelligent and experienced
> off-road cyclist could seriously dispute that in the situation as
> described, it may indeed be more energy efficient to walk.

I guess it could be the case that technically fewer joules came into
play, but we'd gone a long way up a big hill and our spinning muscles
were well spun. It was getting quite boring spinning them more, and
however /efficient/ they were at getting me up, they were tired.

But even if fewer joules came into play I wouldn't say it was relevant
to the simpler basic question of "was I better off walking or cycling at
the time?". Walking was the winner, it was subjectively easier, and
objectively quicker.

Biological and psychological factors of muscle tiredness trump "oh well,
it's just force times distance, you can't break the laws of physics you
know!" as far as /my/ body is concerned!

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Tony Raven[_2_]]

" > wrote in
oups.com:

>
> The first obvious omission is the weight of the bicycle (as you admit
> below) which is a significant penalty for the cyclist,

However if you are walking with the bicycle you still have to lift its
weight up the elevation so that drops out the equation. It only matters if
the choice is between walking up the hill without the bicycle vs cycling up
the hill with.

>
> I really find it hard to believe that an intelligent and experienced
> off-road cyclist could seriously dispute that in the situation as
> described, it may indeed be more energy efficient to walk.
>

According to measurements done by Schwalbe using SRM power cranks on a 500m
uphill grade a gravel surface increases the power needed by ~30% and a
grass meadow increased it by ~80%, depending on tyre width and pressure, so
still probably well inside the walking efficiency. [For safety adds
caveats of boggy ground, ground littered with big boulders etc etc]

I have already said that there are lots of caveats I omitted to my original
response to Artemesia's post starting this thread (<46e03452$0$7753
>). Knowing Artemesia's cycling styles from her
posting history here I doubt very much that any of the scenarios being
posted to attack my original answer are of any relevance to her cycling.
YMMV


--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Peter Clinch]

Tony Raven wrote:
> Peter Clinch > wrote in
> :
>> I think that's already been accepted and understood here.
>
> Apparently not as Alan clearly said "We all know cycling is more
> efficient in general, the question was whether
> that's still true on steep uneven ground where walking may be quicker."

I was just composing a reply to that myself when I read it again, and
relaised that it doesn't make it clear he doesn't understand the issue.

> But I doubt that rough grassy fields are relevant to Artemesia's original
> question.

It emphatically isn't, but that wasn't what Alan was talking about.
Thread drift, if you can imagine such a thing! ;-)

> As for tired muscles, the evidence is that the efficiency does not
> change, the muscles just get limited in the energy throughput, consuming
> less energy and putting out less energy.

Which is what I've supposed all along, but do you want to get the top of
the hill in the most optimally energy efficient way, or the most
subjectively /comfortable/ way right there and then? I, and I suspect
Artemesia, and the majority of other cyclists will prefer the most
subjectively comfortable way, even if it's slower. And especially if
it's quicker.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Tony Raven[_2_]]

Peter Clinch > wrote in
:
>
> Which is what I've supposed all along, but do you want to get the top
> of the hill in the most optimally energy efficient way, or the most
> subjectively /comfortable/ way right there and then? I, and I suspect
> Artemesia, and the majority of other cyclists will prefer the most
> subjectively comfortable way, even if it's slower. And especially if
> it's quicker.
>

Ah but that's a debate about effectiveness, not efficiency ;-)

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Peter Clinch]

Tony Raven wrote:

> Ah but that's a debate about effectiveness, not efficiency ;-)

Indeed, but I will go so far as to suggest the possibility that
Artemesia is primarily interested in "effectiveness", even if she /said/
"efficiency".

There are times when it's useful not to be wearing one's physics hat...

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Tony Raven[_2_]]

Peter Clinch > wrote in news:5kd385F34a0gU1
@mid.individual.net:

> Tony Raven wrote:
>
>> Ah but that's a debate about effectiveness, not efficiency ;-)
>
> Indeed, but I will go so far as to suggest the possibility that
> Artemesia is primarily interested in "effectiveness", even if she /said/
> "efficiency".

No she was definitely wearing the physics hat with postulating "ideal"
cycles with infinitely low gears and not limited by falling over ;-)

>
> There are times when it's useful not to be wearing one's physics hat...
>

But physics hats are great for getting a thread going - almost as good as
polystyrene hats ;-)

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Artemisia[_2_]]

On 7 sep, 15:28, Peter Clinch > wrote:

> Which is what I've supposed all along, but do you want to get the top of
> the hill in the most optimally energy efficient way, or the most
> subjectively /comfortable/ way right there and then? I, and I suspect
> Artemesia, and the majority of other cyclists will prefer the most
> subjectively comfortable way, even if it's slower. And especially if
> it's quicker.

Exactly - I guess I didn't phrase my initial question correctly. I
should say, for the same speed and distance uphill, which will get me
less out of breathe, walking or cycling?

I hadn't considered the energy throughput, just the energy output.

Cheers,

EFR
Ile de France

[Tony Raven[_2_]]

Artemisia > wrote in news:1189175506.087339.182640
@d55g2000hsg.googlegroups.com:

> On 7 sep, 15:28, Peter Clinch > wrote:
>
>> Which is what I've supposed all along, but do you want to get the top of
>> the hill in the most optimally energy efficient way, or the most
>> subjectively /comfortable/ way right there and then? I, and I suspect
>> Artemesia, and the majority of other cyclists will prefer the most
>> subjectively comfortable way, even if it's slower. And especially if
>> it's quicker.
>
> Exactly - I guess I didn't phrase my initial question correctly. I
> should say, for the same speed and distance uphill, which will get me
> less out of breathe, walking or cycling?
>

For me walking because I can walk more slowly than I can cycle. It will
take longer and use more energy but I will be less out of breath doing it.


--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Artemisia[_2_]]

On 7 sep, 14:37, "Clive George" > wrote:

> But more importantly with the trike you've got something you can't do on any
> bike : stop and sit there. So you pedal until you're puffed, put the brakes
> on (with locking device/velcro as appropriate) and sit there relaxing, coz
> you can.

Ah, but on the bike I just hop off , you see. When I get huffed, I
stop by the roadside, standing and visible. It's easy to walk the bike
along with me. Whereas that becomes a lot harder with the trike. So
overall, the hill may be easier with the bike, insofar as it's a walk,
with stops whenever needed.

I'm trying to figure out if the trike is an advantage or an
unnecessary bother on the morning commute.

Apart from that, I could also take the bus. ;°>

EFR
Ile de France

[Artemisia[_2_]]

On 7 sep, 14:44, "

> Now in the case of a steep hill with grass and thus relatively high
> rolling resistance, it may be that the increased rolling resistance
> more than makes up for the difference of cycling not being a weight
> bearing exercise.

I should mention that in the case of my particular hill, there's no
grass; its all smooth tarmac. Its just dark and windey and infernally
steep and there are cars on it. You can tell how steep it is by how
much the cars are stinking - I get practically asphyxiated whenever
I'm passed by one.

But I can see how the presence of grass would complicate the problem
in abstract.

EFR
Ile de France

[Clive George]

"Artemisia" > wrote in message
oups.com...
On 7 sep, 14:37, "Clive George" > wrote:

>> But more importantly with the trike you've got something you can't do on
>> any
>> bike : stop and sit there. So you pedal until you're puffed, put the
>> brakes
>> on (with locking device/velcro as appropriate) and sit there relaxing,
>> coz
>> you can.
>
>Ah, but on the bike I just hop off , you see. When I get huffed, I
>stop by the roadside, standing and visible. It's easy to walk the bike
>along with me. Whereas that becomes a lot harder with the trike. So
>overall, the hill may be easier with the bike, insofar as it's a walk,
>with stops whenever needed.

Yes, pushing the trike isn't good. So you don't do it. It's a different
approach - rather than walking, you stop, relax, then ride again. Or indeed
ride _really_ slowly - which you can, because there's no need for balancing.

>I'm trying to figure out if the trike is an advantage or an
>unnecessary bother on the morning commute.

I think the only way you'll find it out is by trying it. I reckon the trike
will be less efficient than the bike, but other factors may make it more
effective for you.

cheers,
clive

[Rob Morley]

In article . com>,
Artemisia
says...

> Exactly - I guess I didn't phrase my initial question correctly. I
> should say, for the same speed and distance uphill, which will get me
> less out of breathe, walking or cycling?
>
On a tadpole trike on road in the right gear I reckon pedalling should
easily win (especially if you factor the dismount/remount time into the
speed calculation), but if you pick the wrong gear you might get puffed.

[Tony Raven[_2_]]

Artemisia > wrote in news:1189176557.361981.144840
@r34g2000hsd.googlegroups.com:
>
> I should mention that in the case of my particular hill, there's no
> grass; its all smooth tarmac. Its just dark and windey and infernally
> steep and there are cars on it. You can tell how steep it is by how
> much the cars are stinking - I get practically asphyxiated whenever
> I'm passed by one.
>

You need one of these:
http://www.egopt.co.uk/

Users report double takes from people as they pedal seemingly effortlessly
up steep hills

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[gary2006uk]

On 7 Sep, 13:44, "
> wrote:
> On Sep 6, 7:09 pm, Artemisia > wrote:
>
> > Peter Clinch wrote:
>
> > > I recall one incident when a pal and I were taking our MTBs up a fairly
> > > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> > So isn't it actually more efficient energy use to walk uphill than to
> > pedal, even if you do have unimaginably low gears and no topple-over on
> > a trike?
>
> > I'm thinking perhaps the only advantage of trying to pedal up my hills
> > is the inconvenience of trying to stand up out of a recumbent...
>
> > EFR
> > Ile de France
>
> Cycling (particularly on a recumbent!) is not a weight bearing
> exercise like walking. That is to say, cycling up a hill requires you
> to only move your center of mass up the slope, not carry it. When you
> carry something up a hill you need to not only move it up the slope,
> you need to support it's weight the whole time too. Think about
> carrying rocks up a hill with a wheelbarrow vs a backpack. When
> cycling the center of mass stays pretty still and thus follows the
> slope of the hill without too much extra energy spent. Walking makes
> the center of mass bob up and down a bit which uses energy that
> cycling doesn't. Cycling has the added weight of the bike, and the
> resistance of the drivetrain, rolling resistance, and wind resistance,
> but in terms of calories per distance at slow speeds where wind and
> rolling resistance are minimal, cycling will always be more efficient.
> At high speeds where the exponential wind resistance is much greater,
> one needs to expend a lot more energy to overcome this resistance, and
> then walking is more efficient in terms of calories per distance. A
> lot slower too!
>
> Now in the case of a steep hill with grass and thus relatively high
> rolling resistance, it may be that the increased rolling resistance
> more than makes up for the difference of cycling not being a weight
> bearing exercise. Gearing and what is a comfortable range of cadence
> and force generation for the leg muscles comes into play too.
>
> If you try pushing someone on a bike on a flat feild of grass you can
> see how much resistance there is. And since it seems that riding up
> this hill vs walking was more or less a wash despite the extra rolling
> resistance, this suggests to me that cycling is that much easier than
> walking by the same amount of effort it took to push the person on the
> grass. (That made sense to me at least...)
>
> Joseph

cycling up steep hills is less efficient than walking.ive seen many
mountain bikers riding,legs spinning round,hardly moving,whilst
walking i have also passed bikers on the mountains.ive even seen
cyclists in very low gear on the road,in too low a gear,legs going
round like mad,hardly moving,very innefficient,one turn on my gear on
a racing bike leaves them standing.i think some of them dont want to
put any hard effort into cycling.ive also seen bikers on low gear
dawdling along,no physical effort being used,they cant be benifiting
physicaly in fitness riding that slow.god forbid if they ended up on a
hill on a cycle track.

[Tony Raven[_2_]]

gary2006uk > wrote in
oups.com:

> cycling up steep hills is less efficient than walking.ive seen many
> mountain bikers riding,legs spinning round,hardly moving,whilst
> walking i have also passed bikers on the mountains.ive even seen
> cyclists in very low gear on the road,in too low a gear,legs going
> round like mad,hardly moving,very innefficient,one turn on my gear on
> a racing bike leaves them standing.i think some of them dont want to
> put any hard effort into cycling.ive also seen bikers on low gear
> dawdling along,no physical effort being used,they cant be benifiting
> physicaly in fitness riding that slow.god forbid if they ended up on a
> hill on a cycle track.
>

You've mixed up lots of things that have nothing to do with efficiency
and some that do and you have the wrong way round. For example spinning
quickly is more, not less, efficient than your "one turn on my gear".
Speed has nothing to do with efficiency unless you are starting to go
fast enough to introduce air resistance. Those fast spinning cyclists
you deride are probably getting up that hill far more efficiently than
your wasteful technique.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Peter Clinch]

Tony Raven wrote:
> Artemisia > wrote in news:1189175506.087339.182640
> @d55g2000hsg.googlegroups.com:
>
>> On 7 sep, 15:28, Peter Clinch > wrote:
>>
>>> Which is what I've supposed all along, but do you want to get the top of
>>> the hill in the most optimally energy efficient way, or the most
>>> subjectively /comfortable/ way right there and then? I, and I suspect
>>> Artemesia, and the majority of other cyclists will prefer the most
>>> subjectively comfortable way, even if it's slower. And especially if
>>> it's quicker.
>> Exactly - I guess I didn't phrase my initial question correctly. I
>> should say, for the same speed and distance uphill, which will get me
>> less out of breathe, walking or cycling?

> For me walking because I can walk more slowly than I can cycle. It will
> take longer and use more energy but I will be less out of breath doing it.

But she says "at the same speed".

It's still not a black and white answer, because your muscles
aren't all working in a common pool in a precisely similar way
between the two modes so it's not just a case of working out the
energy needed.

There will be times when walking will work better, and there are
times when cycling will work better. Variables include the hill,
the wind, your tiredness, how fast you can hit the bottom of the
hill, how gung-ho you feel at the time, and so on.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Julian Gallop[_3_]]

Tony Raven wrote:
> gary2006uk > wrote in
> oups.com:
>
>
>>cycling up steep hills is less efficient than walking.ive seen many
>>mountain bikers riding,legs spinning round,hardly moving,whilst
>>walking i have also passed bikers on the mountains.ive even seen
>>cyclists in very low gear on the road,in too low a gear,legs going
>>round like mad,hardly moving,very innefficient,one turn on my gear on
>>a racing bike leaves them standing.i think some of them dont want to
>>put any hard effort into cycling.ive also seen bikers on low gear
>>dawdling along,no physical effort being used,they cant be benifiting
>>physicaly in fitness riding that slow.god forbid if they ended up on a
>>hill on a cycle track.
>>
>
>
> You've mixed up lots of things that have nothing to do with efficiency
> and some that do and you have the wrong way round. For example spinning
> quickly is more, not less, efficient than your "one turn on my gear".
> Speed has nothing to do with efficiency unless you are starting to go
> fast enough to introduce air resistance. Those fast spinning cyclists
> you deride are probably getting up that hill far more efficiently than
> your wasteful technique.
>
I think that when the gear becomes really low, the effort of rotating
the legs many times over a short distance becomes significant. Whereas
with walking, the stride length is not decreased very much.

Julian Gallop

[Tony Raven[_2_]]

Peter Clinch > wrote in
:
>
>> For me walking because I can walk more slowly than I can cycle. It
>> will take longer and use more energy but I will be less out of breath
>> doing it.
>
> But she says "at the same speed".
>

That's another reason - I'd fall off cycling at the speed I would walk ;-)

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[[email protected]]

On Sep 7, 10:25 pm, Tony Raven > wrote:
> " > wrote groups.com:
>
>
>
> > The first obvious omission is the weight of the bicycle (as you admit
> > below) which is a significant penalty for the cyclist,
>
> However if you are walking with the bicycle you still have to lift its
> weight up the elevation so that drops out the equation. It only matters if
> the choice is between walking up the hill without the bicycle vs cycling up
> the hill with.
>
>
>
> > I really find it hard to believe that an intelligent and experienced
> > off-road cyclist could seriously dispute that in the situation as
> > described, it may indeed be more energy efficient to walk.
>
> According to measurements done by Schwalbe using SRM power cranks on a 500m
> uphill grade a gravel surface increases the power needed by ~30% and a
> grass meadow increased it by ~80%, depending on tyre width and pressure, so
> still probably well inside the walking efficiency. [For safety adds
> caveats of boggy ground, ground littered with big boulders etc etc]

Why do you think this is well inside the walking efficiency?

> I have already said that there are lots of caveats I omitted to my original
> response to Artemesia's post starting this thread (<46e03452$0$7753
> >). Knowing Artemesia's cycling styles from her
> posting history here I doubt very much that any of the scenarios being
> posted to attack my original answer are of any relevance to her cycling.

I'm happy to agree that on a proper road surface, riding up a steep
hill is likely to be clearly more efficient than pushing a bicycle
(and even walking without a bicycle, at least usually). Off-road, it
depends heavily on the conditions, and if the conditions are soft
enough (or slippery, something else we haven't mentioned) for walkers
to actually be overtaking cyclists then I think it is reasonable to
assume the reverse. I think most people who ride off-road in the UK
have encountered such situations.

Your claim "Cycling is a more efficient way of moving than walking so
cycling up will use less energy" is clearly false as a general
statement, and although it might seem picky to demand every detailed
caveat, the post it was replying to specifically described a situation
where it is at least possible, and perhaps likely, to be false. Worse,
you repeated the assertion in response to the specific question "Is
cycling more efficient than walking under all circumstances?" thus
apparently indicating that there were no caveats (other than the
weight of the bicycle, which as you are now keen to point out is not
relevant to walking v pushing)...

James

[Daniel Barlow]

wrote:
> I've found other references on the same lines that suggest that
> calories per hour for cycling and walking are about the same.

This sounds like an utterly meaningless comparison. Calories expended
while cycling can very from approximately nil (freewheeling) to many
many (anaerobic exercise while sprinting). Calories expended while
walking vary from whatever you expend simply by standing on two legs to
- well, probably a similar value of "many many", if you walk briskly
enough up sufficiently steep hills. Within these ranges, whatever
arbitrary figure you pick for "calories per hour walking" is bound to
have a match somewhere on the cycling graph.

There is no free path to "more energy expended" that doesn't involve
working harder.


-dan

[Clive George]

"Daniel Barlow" > wrote in message
...

> There is no free path to "more energy expended" that doesn't involve
> working harder.

Awww. There goes another plan for world domination :-(

cheers,
clive

[[email protected]]

On Sep 6, 11:09 am, Artemisia > wrote:
> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?
>
> I'm thinking perhaps the only advantage of trying to pedal up my hills
> is the inconvenience of trying to stand up out of a recumbent...
>
> EFR
> Ile de France

Dear Artemisia,

Bicycles often beat runners up steep roads. No runner could match
Armstrong zooming up the Alp d'Huez at an average speed of over 16 mph
(13 mph is the best that marathon runners do on the flats).

But even a paved road can eventually get so steep that the rider is
reduced to either heaving slowly with great force on pedals with
gearing too high, or else moving the feet in circles while covering no
more distance than a stride.

Once the feet travel as far in a circle as they would while walking,
you're at an overall effective 1-to-1 ratio, and it's hard to come up
with an explanation why this would be more effective than pushing the
bike up the same slope with the natural walking motion.

Dead spots in the pedal cycle don't help, either.

Contestants in the Fargo Street Hill Climb in Los Angeles never try
pushing up the hill, find it too difficult, climb on the bike, and
start to pedal.

Instead, the less successful contestants tack back and forth across
the street to reduce the slope and eventually come to a halt while
trying to turn back across the slope. Then they walk quite easily up
the hill that they couldn't pedal up.

Here's a video from the helmet of an older contestant, gearing
unknown, who gets a little ways up the hill, starts tacking back and
forth, eventually stops, pauses--and then walks straight up the hill
at about 2:52:

http://www.youtube.com/watch?v=d0mECFP76vA

Note that the video is much steadier as he walks straight up.

No one ever claims that it's easy to climb Fargo--even fellows who go
up it dozens of times are puffing and straining and spinning. But any
reasonably active person can push a bike to the top without the
dramatics--that's why there's no Fargo Hill Climb for pedestrians.

Spectators simply walk up the hill--no one finds it easier to pedal up
the sidewalk.

Of course, the point at which walking and pushing the bike is more
efficient/effective/rapid/et cetera depends on how steep the slope is,
how powerful the rider is, and how low the gearing is. I doubt that
I'd have gotten as far as the fellow who wore the camera on his helmet
for our benefit.

For more Fargo pictures:

http://www.lawheelmen.org/fargo.htm

A lone climber with more power and high gearing heaves all the way up
Fargo, mostly straight:

http://www.youtube.com/watch?v=_99hT57NAwo&NR=1

Cheers,

Carl Fogel

[Don Whybrow]

wrote:
>
> Here's a video from the helmet of an older contestant, gearing
> unknown, who gets a little ways up the hill, starts tacking back and
> forth, eventually stops, pauses--and then walks straight up the hill
> at about 2:52:
>
> http://www.youtube.com/watch?v=d0mECFP76vA
>
> Note that the video is much steadier as he walks straight up.

It looks to me that the camera is mounted in the bike, not the helmet.


--
Don Whybrow

Sequi Bonum Non Time

Discordianism: Where reality is a figment of your imagination

[Tony Raven[_2_]]

Don Whybrow > wrote in news:5ke9n9F3aog0U1
@mid.individual.net:
>>
>> http://www.youtube.com/watch?v=d0mECFP76vA
>>
>> Note that the video is much steadier as he walks straight up.
>
> It looks to me that the camera is mounted in the bike, not the helmet.
>
>

Definitely mounted on the bars. The give away is where the camera is
looking right at the point where the turns start up against the kerbs.
Which makes the walking one the steadiness of a leaned over bike (check the
horizon) being wheeled up the hill. You need to pay a lot of attention to
be able to shoot a steady video while walking. The pro's use all sorts of
counterbalanced inertial gizmos to float the camera free of the body
movement.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tony Raven[_2_]]

wrote in
oups.com:
>
> Once the feet travel as far in a circle as they would while walking,
> you're at an overall effective 1-to-1 ratio, and it's hard to come up
> with an explanation why this would be more effective than pushing the
> bike up the same slope with the natural walking motion.
>

Its quite easy to explain. While cycling the only thing moving to first
order is your legs going in circles and most of the energy used in that
goes into forward motion. When walking with each step you lift your
upper body up which uses energy and then at the end of the step it drops
back down again. Unfortunately muscles don't work in reverse to recover
the potential energy as the body drops down so it is lost and a source of
significant inefficiency.

Try walking on the flat concentrating on keeping your upper body still as
you move forward and you will quickly realise just how unnatural a way of
walking it is. Do the same with cycling and for most people it is the
natural way sat on the saddle. Even if you stand on the pedals and move
your body up and down as you pedal, the down comes from pushing the pedal
down with your body weight which is converting its potential energy into
forward motion.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Artemisia]

wrote:

> Here's a video from the helmet of an older contestant, gearing
> unknown, who gets a little ways up the hill, starts tacking back and
> forth, eventually stops, pauses--and then walks straight up the hill
> at about 2:52:
>
> http://www.youtube.com/watch?v=d0mECFP76vA

Thanks for that extremely interesting footage. It illustrates the crux
of my question. The guy is actually going a much greater _distance_ on
his bike because he needs to weave back and forth across the angle of
the rise.

Are there no trikes in this competition? I'd be most curious to see how
the tricycle fares in this situation in comparison to the cyclists and
pedestrians.


> A lone climber with more power and high gearing heaves all the way up
> Fargo, mostly straight:
>
> http://www.youtube.com/watch?v=_99hT57NAwo&NR=1

And he's immensely fit, and chapeau; but you see that by going straight
(assuming that one can stay upright), he is much faster than the ped
who's also going straight.

Cheers,

EFR
Ile de France

[Simon Brooke]

in message >, Artemisia
') wrote:

> wrote:
>
>> Here's a video from the helmet of an older contestant, gearing
>> unknown, who gets a little ways up the hill, starts tacking back and
>> forth, eventually stops, pauses--and then walks straight up the hill
>> at about 2:52:
>>
>> http://www.youtube.com/watch?v=d0mECFP76vA
>
> Thanks for that extremely interesting footage. It illustrates the crux
> of my question. The guy is actually going a much greater _distance_ on
> his bike because he needs to weave back and forth across the angle of
> the rise.

He's ridiculously overgeared for this climb. OK, it's a special situation,
and you probably don't normally have your bike set up to deal with that
special situation - but if you're going to a particular competition where
getting up that hill is what you're competing to do, fitting lower gears
makes sense.

> Are there no trikes in this competition? I'd be most curious to see how
> the tricycle fares in this situation in comparison to the cyclists and
> pedestrians.

Bikes have an effective lower limit speed - the speed at which you can no
longer balance and stay upright. Trikes don't have that problem. Fit lower
gears and spin, and the only thing that limits your climbing ability is
traction.

--
(Simon Brooke) http://www.jasmine.org.uk/~simon/

:: Wisdom is better than weapons of war ::
:: Ecclesiastes 9:18 ::

[[email protected]]

On Sep 8, 10:56 am, Artemisia > wrote:
> wrote:
> > Here's a video from the helmet of an older contestant, gearing
> > unknown, who gets a little ways up the hill, starts tacking back and
> > forth, eventually stops, pauses--and then walks straight up the hill
> > at about 2:52:
>
> > http://www.youtube.com/watch?v=d0mECFP76vA
>
> Thanks for that extremely interesting footage. It illustrates the crux
> of my question. The guy is actually going a much greater _distance_ on
> his bike because he needs to weave back and forth across the angle of
> the rise.
>
> Are there no trikes in this competition? I'd be most curious to see how
> the tricycle fares in this situation in comparison to the cyclists and
> pedestrians.
>
> > A lone climber with more power and high gearing heaves all the way up
> > Fargo, mostly straight:
>
> > http://www.youtube.com/watch?v=_99hT57NAwo&NR=1
>
> And he's immensely fit, and chapeau; but you see that by going straight
> (assuming that one can stay upright), he is much faster than the ped
> who's also going straight.
>
> Cheers,
>
> EFR
> Ile de France

Dear Artemisia,

I suspect that rider would go much faster up Fargo Street if he simply
walked up it, pushing his bike, with the same amount of effort--he's
heaving with all his might with every pedal stroke, barely able to
keep the pedals moving past the dead spots.

Most of these discussions of bicycles versus walking on extreme slopes
end up mentioning that the pedestrian can start and stop without much
trouble at any given point, while the bicyclist is in constant fear of
stopping and being utterly unable to get going again--loss of forward
motion means getting off and pushing the bike up the hill.

A cruel way to illustrate the practical disadvantages of the bicycle
on such extreme slopes is to add some roots and ledges to the smooth
pavement. A curb six inches highthat a pedestrian simply steps over
without breaking stride looms like six-foot fence to the bicyclist.

Bicycles are machines that rely on smooth and relatively level
surfaces that allow them to eliminate most friction and to apply huge
leverage. With most friction eliminated, we trade force for distance,
applying a small force to propel us a long distance.

For example, on level ground with a high 53x11 gear on a 700c tire
about 2120 mm in circumference and a 175 mm crank, the rear tire moves
9.3 times as far as the rider's foot. Pushing the pedal a full turn
(43.67 inches, just under four feet) moves you almost 34 feet. Once
you get up to speed, an unhurried cadence of about 52 rpm produces 20
mph--as long as there's no hill.

On a hill like Fargo Street, you can't even stand on the pedals and
stay in place with such high gearing. Gravity is trying to roll you
back down the hill with the same 9.3 to 1 leverage acting in reverse
against you.

To pedal up such hills, riders must either heave with enormous force
against gearing that's too high or else use ultra-low gearing that
reduces them to walking speeds. Once you give up the leverage
advantage of gearing and are no longer trading force for distance,
you're fighting your way up the hill at a speed so low that the
advantage of rolling has become inconsequential.

(Consider how far you'd coast up Fargo Street if you stopped pedaling--
not significantly farther than you'd go if you suddenly stopped
walking.)

For the same 700c wheel and 175 mm crank, a 20 front x 38 rear
produces a roughly 1-to-1 overall pedal-to-tire movement (14.0 gear
inches for riders who prefer that reckoning). At 48 rpm, you'd grind
up Fargo Street at 2 mph. Your feet would be moving in unnatural
circles in steps nearly fourteen inches high, fighting dead spots
every step of the way, and traveling just as far as they would if you
were walking naturally and pushing the bike.

I doubt that the Fargo Street contestants will ever start pushing
their bikes up that hill for a better workout or to impress the
spectators.

Cheers,

Carl Fogel

[Tony Raven[_2_]]

Simon Brooke > wrote in
:

>
> Bikes have an effective lower limit speed - the speed at which you can
> no longer balance and stay upright.

There is another limit which is the ability to keep the front wheel on the
ground and not loop out backwards. Like balance, experience helps a lot
with better weight distribution control between rear wheel traction and
front wheel staying down. More of an issue off road where surface
irregularities help the front wheel lift and the rear wheel need weight for
traction.


--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tony Raven[_2_]]

wrote in news:1189273789.418108.208290
@y42g2000hsy.googlegroups.com:

>
> I suspect that rider would go much faster up Fargo Street if he simply
> walked up it, pushing his bike, with the same amount of effort--he's
> heaving with all his might with every pedal stroke, barely able to
> keep the pedals moving past the dead spots.

You continue your confused analysis of the situation mixing up efficiency
and effectiveness and many other things. The sample you chose is just a
poor choice of gearing.

Cyclists in the UK regularly cross the Hardnott and Wrynose Passes each
weekend which are the same gradient as Fargo St but climb the best part
of 1000ft and have no width to weave about. Every year 800 cyclists
cross them as part of the Fred Whitton Challenge where they hit the
passes 100 miles and 12,000ft of ascent into the ride. Its even been done
on a tandem.

Yes there are limits to what you can cycle up but also what you can walk
up and on the downhill side cycling wins big time. So the fact you can
find one cyclist who can't get up Fargo St in too big a gear says little
about the relative efficiencies or effectiveness.
http://www.fredwhittonchallenge.org.uk/images/hardknott-big.jpg
http://www.fredwhittonchallenge.org.uk/images/wrynose-big.jpg
http://www.bikeit.eclipse.co.uk/localrides/ride2/index.htm
http://www.bikeit.eclipse.co.uk/fredwhitton2006/index.htm

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Mike A Schwab]

On Sep 7, 12:43 am, Artemisia > wrote:
> On 7 sep, 02:17, "Roger Zoul" > wrote:
>
> > Can one cycle up a 45 degree slope? Isn't that 100% grade?
>
> Well if it can't even be done, then it can't be as efficient, can it?
>
> EFR
> Ile de France

A vertical cliff face would be infinite % grade.

[[email protected]]

On Sep 8, 1:08 pm, Tony Raven > wrote:
> wrote in news:1189273789.418108.208290
> @y42g2000hsy.googlegroups.com:
>
>
>
> > I suspect that rider would go much faster up Fargo Street if he simply
> > walked up it, pushing his bike, with the same amount of effort--he's
> > heaving with all his might with every pedal stroke, barely able to
> > keep the pedals moving past the dead spots.
>
> You continue your confused analysis of the situation mixing up efficiency
> and effectiveness and many other things. The sample you chose is just a
> poor choice of gearing.
>
> Cyclists in the UK regularly cross the Hardnott and Wrynose Passes each
> weekend which are the same gradient as Fargo St but climb the best part
> of 1000ft and have no width to weave about. Every year 800 cyclists
> cross them as part of the Fred Whitton Challenge where they hit the
> passes 100 miles and 12,000ft of ascent into the ride. Its even been done
> on a tandem.
>
> Yes there are limits to what you can cycle up but also what you can walk
> up and on the downhill side cycling wins big time. So the fact you can
> find one cyclist who can't get up Fargo St in too big a gear says little
> about the relative efficiencies or effectiveness.http://www.fredwhittonchallenge.org.uk/images/hardknott-big.jpghttp://www.fredwhittonchallenge.org.uk/images/wrynose-big.jpghttp://www.bikeit.eclipse.co.uk/localrides/ride2/index.htmhttp://www.bikeit.eclipse.co.uk/fredwhitton2006/index.htm
>
> --
> Tony
>
> " I would never die for my beliefs because I might be wrong."
> Bertrand Russell

Dear Tony,

All cyclists reach a practical point at which they can't pedal up the
slope, given their fitness and gearing.

Consider the ultimate example, which ignores practical problems like
getting started, going fast enough to stay upright, and avoiding
stalling on small obstacles, namely a pedal-operated elevator using
whatever overall gearing the rider prefers to raise the rider up a
geared track.

Why would pedaling and putting the power through transmission losses
be more efficient/effective/et cetera than just climbing a ladder? How
does enforcing a much narrower range of speed and cadence improve
things?

The natural motion of climbing would seem to avoid the huge effort
needed to get past dead spots at a low cadence and the considerable
inefficiency of thrashing legs at a much higher cadence than
comfortable climbing--the human leg, freed of the rigid connection
through a geared chain, has an automatic and infinitely variable
"gearing".

Cheers,

Carl Fogel

[Tony Raven[_2_]]

wrote in news:1189282212.500032.53880
@y42g2000hsy.googlegroups.com:
>
> Why would pedaling and putting the power through transmission losses
> be more efficient/effective/et cetera than just climbing a ladder? How
> does enforcing a much narrower range of speed and cadence improve
> things?
>

Go back and read my previous response to you about upper body movement for
your answer.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tom Keats]

In article >,
Tony Raven > writes:
> wrote in
> oups.com:
>>
>> Once the feet travel as far in a circle as they would while walking,
>> you're at an overall effective 1-to-1 ratio, and it's hard to come up
>> with an explanation why this would be more effective than pushing the
>> bike up the same slope with the natural walking motion.
>>
>
> Its quite easy to explain. While cycling the only thing moving to first
> order is your legs going in circles and most of the energy used in that
> goes into forward motion. When walking with each step you lift your
> upper body up which uses energy and then at the end of the step it drops
> back down again. Unfortunately muscles don't work in reverse to recover
> the potential energy as the body drops down so it is lost and a source of
> significant inefficiency.
>
> Try walking on the flat concentrating on keeping your upper body still as
> you move forward and you will quickly realise just how unnatural a way of
> walking it is. Do the same with cycling and for most people it is the
> natural way sat on the saddle. Even if you stand on the pedals and move
> your body up and down as you pedal, the down comes from pushing the pedal
> down with your body weight which is converting its potential energy into
> forward motion.

Ah, but when riding a diamond-frame upright bike up a steep hump,
especially if the bike is heavily rearward laden, the front wheel
tends to lift up, and a lot of upper body effort is involved in
just keeping the front wheel down on the ground. That's what
MTB bar-ends are meant for.

So much consideration is given about left/right balance
in terms of riding a bicycle; and so little is given about
fore/aft balance.

For a seated rider, the steeper the ascent, the more
upper-body effort is required to keep the bike from
flipping over backwards.

Now, I've hauled some heavy bikes up some fairly
steep hills, and I can avow it's a task. Most of
the times in which I've so opted, it was because
it was just too ugly to get mixed-up in motorized
traffic in those circumstances -- otherwise I'd
be worse-off than a pedestrian in the midst of
faster-moving traffic.

Bike lanes in those circumstances are blessings.
But if there aren't any bike lanes, and you have
steepish rollers or hills to deal with, and non-
cycling-conducive conditions -- might as well hoof
it for that stretch, and survive. Even if it means
getting a 40+ lb bike up a 10+% grade, by pulling
it up by the handlebar, as well as pushing it up
by the saddle. And that ain't no fun. In fact
it makes ya feel like a plough horse. Which, as
an hard-working Sagittarian, I already am, so
that's okay for me.

Getting a light bike up a steep hill is peanuts,
when you can appropriately adjust your fore/aft
balance, and appropriately weight the front &
rear wheels. And pace yourself. A lot of riders
go nutz trying to get up that hill fast even though
they're in a low gear -- they spin faster than they
would in a higher gear on the level, and wear themselves
out.

Getting a /load/ up a steep hill can be a challenge.
Especially when the load is on the rear of your bike,
and your bike keeps wanting to wheelie.

The concept of fore/aft balance in cycling is
IMO too neglected. But that's what gets bike
riders up hills.

It gets us down hills too.

That's part of why a bicycle saddle is not a
stationary seat. We need to be able to shift
our weights around on our bikes -- left/right,
fore/aft, up/down. We are not nailed-down to
our bicycles; we have freedom of movement at
our avail. Actually, lots of it. It's like
a dance. So a saddle is not a chair.

Bicycles are balanced in 3 dimensions,
in a 3 dimensional world.

Anyway, there indeed are some steep uphill streets
on which I begrudingly push/pull/otherwise-cajole
my heavy bike, rather than do 2 MPH in the adjacent
car traffic. I /could/ ride on the sidewalk at
2 MPH, but when I legally cross the intersections
as a pedestrian, I have the upper hand in terms of
fault and liability.

I'll tell ya this much -- I am so sick & tired of
only being able to get 14-28T 6-spd freewheels.
I wish I could get at least a 32.

And seatedly riding a conventional diamond-frame
bike up a steep hill indeed does involve some
upper body effort, just to keep the front wheel
down on the ground.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Tony Raven[_2_]]

(Tom Keats) wrote in :
>
> Ah, but when riding a diamond-frame upright bike up a steep hump,
> especially if the bike is heavily rearward laden, the front wheel
> tends to lift up, and a lot of upper body effort is involved in
> just keeping the front wheel down on the ground. That's what
> MTB bar-ends are meant for.
>

Yes, as I've said multiple times before in this thread, we can all dream
up scenarios where one is better than the other but the basic starting
point is still that cycling is more efficient than walking before you add
in other factors such as steps.....

>
> For a seated rider, the steeper the ascent, the more
> upper-body effort is required to keep the bike from
> flipping over backwards.
>

Only really a problem IME off-road where you are having to balance rear
wheel traction with front wheel weighting. On road I've very rarely had
a problem and a cobbled 33% grade is the steepest I've climbed (in a very
low gear!)


> Now, I've hauled some heavy bikes up some fairly
> steep hills, and I can avow it's a task.

As it would be if you were carrying the same load up the same hill on
foot.

>
> Bike lanes in those circumstances are blessings.
> But if there aren't any bike lanes, and you have
> steepish rollers or hills to deal with, and non-
> cycling-conducive conditions -- might as well hoof
> it for that stretch, and survive. Even if it means
> getting a 40+ lb bike up a 10+% grade, by pulling
> it up by the handlebar, as well as pushing it up
> by the saddle. And that ain't no fun. In fact
> it makes ya feel like a plough horse. Which, as
> an hard-working Sagittarian, I already am, so
> that's okay for me.
>

That's not heavy. I used to tandem up 15% grades with a young daughter
on the back and towing a Bob trailer of camping gear and I'm no spring
chicken and not a good hill climber. Why you couldn't cycle a 40lb bike
up a 10% grade puzzles me unless you had the wrong gearing.

>
> I'll tell ya this much -- I am so sick & tired of
> only being able to get 14-28T 6-spd freewheels.
> I wish I could get at least a 32.

Have a look at building your own just replacing the 28 sprocket with a 32
or 34 nicked from a 7 speed Megarange. It'll be slightly thinner but
providing you use the six speed spacer it should work fine. You will
need two chain whips to disassemble the sprockets off the freewheel body
and probably better starting with new rather than trying to disassemble
one that has been tightened on by years of use.

>
> And seatedly riding a conventional diamond-frame
> bike up a steep hill indeed does involve some
> upper body effort, just to keep the front wheel
> down on the ground.
>

Personally I think very little of it is the effort of keeping the front
wheel down (other than on loose lumpy off-road) and most is to do with
using the upper body attached to the bars to push against with the legs
and get more leverage on the cranks. BICBW


--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tom Keats[_4_]]

In article >,
Tony Raven > writes:
> (Tom Keats) wrote in :
>>
>> Ah, but when riding a diamond-frame upright bike up a steep hump,
>> especially if the bike is heavily rearward laden, the front wheel
>> tends to lift up, and a lot of upper body effort is involved in
>> just keeping the front wheel down on the ground. That's what
>> MTB bar-ends are meant for.
>>
>
> Yes, as I've said multiple times before in this thread, we can all dream
> up scenarios where one is better than the other but the basic starting
> point is still that cycling is more efficient than walking before you add
> in other factors such as steps.....

I didn't mention steps.

>> For a seated rider, the steeper the ascent, the more
>> upper-body effort is required to keep the bike from
>> flipping over backwards.
>>
>
> Only really a problem IME off-road where you are having to balance rear
> wheel traction with front wheel weighting.

Try it on-road, with a big sack of spuds or flour
hanging over the outskirts of the milk crate on
your rear rack.

> On road I've very rarely had
> a problem and a cobbled 33% grade is the steepest I've climbed (in a very
> low gear!)

Yes, and I've done similar in environments where
antisocial car drivers weren't wont to aim at me.

>> Now, I've hauled some heavy bikes up some fairly
>> steep hills, and I can avow it's a task.
>
> As it would be if you were carrying the same load up the same hill on
> foot.
>
>>
>> Bike lanes in those circumstances are blessings.
>> But if there aren't any bike lanes, and you have
>> steepish rollers or hills to deal with, and non-
>> cycling-conducive conditions -- might as well hoof
>> it for that stretch, and survive. Even if it means
>> getting a 40+ lb bike up a 10+% grade, by pulling
>> it up by the handlebar, as well as pushing it up
>> by the saddle. And that ain't no fun. In fact
>> it makes ya feel like a plough horse. Which, as
>> an hard-working Sagittarian, I already am, so
>> that's okay for me.
>>
>
> That's not heavy. I used to tandem up 15% grades with a young daughter
> on the back and towing a Bob trailer of camping gear and I'm no spring
> chicken and not a good hill climber. Why you couldn't cycle a 40lb bike
> up a 10% grade puzzles me unless you had the wrong gearing.

Heh. Well, bully for you, I guess.
I'm such a weakling.

>> I'll tell ya this much -- I am so sick & tired of
>> only being able to get 14-28T 6-spd freewheels.
>> I wish I could get at least a 32.
>
> Have a look at building your own just replacing the 28 sprocket with a 32
> or 34 nicked from a 7 speed Megarange. It'll be slightly thinner but
> providing you use the six speed spacer it should work fine. You will
> need two chain whips to disassemble the sprockets off the freewheel body
> and probably better starting with new rather than trying to disassemble
> one that has been tightened on by years of use.

I'm talking about ready-to-go, old-style, screw-on
HyperGlides. You can't take those things apart very
easily, and when you do, an whole bunch of little
bearing balls spill out and flow across your floor
like baby spiders from a cactus that shouldn't have
been smuggled-in from Mexico.

>> And seatedly riding a conventional diamond-frame
>> bike up a steep hill indeed does involve some
>> upper body effort, just to keep the front wheel
>> down on the ground.

> Personally I think very little of it is the effort of keeping the front
> wheel down

I differ in that opinion, or for that matter,
experience.

> (other than on loose lumpy off-road) and most is to do with
> using the upper body attached to the bars to push against with the legs
> and get more leverage on the cranks. BICBW

On less-steep hills, a seated rider can shove-back in the
saddle and sort of attempt to become recumbent, and push
more forward than downward on the pedals. That actually
puts /more/ weight & traction on the rear wheel. I doubt
that would work very well on your 15% grades.

As for steadying the (stiff) upper body on the handlebar
to direct a rider's force into the cranks -- wouldn't
that consume effort? Not that I agree that that's
what happens. No, I must still suspect that on an ascent,
the rider is balancing his bicycle fore/aft as well as
right/left, and that's a very dynamic process.

In other words, I contend a seated ascending rider is
/not/ just going through the same motions as a rider
on flatland, only slower by dint of lower gearing.


cheers,
Tom
--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Tom Keats]

In article . com>,
writes:

> Dear Artemisia,
>
> I suspect that rider would go much faster up Fargo Street if he simply
> walked up it, pushing his bike, with the same amount of effort--he's
> heaving with all his might with every pedal stroke, barely able to
> keep the pedals moving past the dead spots.
^^^^^^^^^^

What causes those "dead spots" anyways?

Is it physiological, or mechanical, or both,
or neither?

If (the legs of) a rider going up a steep grade
experiences dead spots, it occurs to me that the
drivers on a steam locomotive going up a steep
grade might also experience similar dead spots.

Anyways, I rather dislike those dead spots.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Clive George]

"Tom Keats" > wrote in message
...

>>> I'll tell ya this much -- I am so sick & tired of
>>> only being able to get 14-28T 6-spd freewheels.
>>> I wish I could get at least a 32.
>>
>> Have a look at building your own just replacing the 28 sprocket with a 32
>> or 34 nicked from a 7 speed Megarange. It'll be slightly thinner but
>> providing you use the six speed spacer it should work fine. You will
>> need two chain whips to disassemble the sprockets off the freewheel body
>> and probably better starting with new rather than trying to disassemble
>> one that has been tightened on by years of use.
>
> I'm talking about ready-to-go, old-style, screw-on
> HyperGlides. You can't take those things apart very
> easily, and when you do, an whole bunch of little
> bearing balls spill out and flow across your floor
> like baby spiders from a cactus that shouldn't have
> been smuggled-in from Mexico.

I've never met a freewheel - yes, the old-style type you're talking about -
where one couldn't remove the sprockets separately.

cheers,
clive

[Rob Morley]

In article >, Tom Keats
says...
forward motion.
>
> Ah, but when riding a diamond-frame upright bike up a steep hump,
> especially if the bike is heavily rearward laden, the front wheel
> tends to lift up, and a lot of upper body effort is involved in
> just keeping the front wheel down on the ground.

What exactly are you supposed to push against to keep the front wheel
down?

[Steve Gravrock]

On 2007-09-09, Rob Morley > wrote:
> In article >, Tom Keats
> says...
> forward motion.
>>
>> Ah, but when riding a diamond-frame upright bike up a steep hump,
>> especially if the bike is heavily rearward laden, the front wheel
>> tends to lift up, and a lot of upper body effort is involved in
>> just keeping the front wheel down on the ground.
>
> What exactly are you supposed to push against to keep the front wheel
> down?

You don't push against anything. You pull up on the handlebars, which
has the effect of pulling your upper body down and forward.

[[email protected]]

On Sep 8, 2:52 pm, Tony Raven > wrote:
> wrote in news:1189282212.500032.53880
> @y42g2000hsy.googlegroups.com:
>
>
>
> > Why would pedaling and putting the power through transmission losses
> > be more efficient/effective/et cetera than just climbing a ladder? How
> > does enforcing a much narrower range of speed and cadence improve
> > things?
>
> Go back and read my previous response to you about upper body movement for
> your answer.
>
> --
> Tony
>
> " I would never die for my beliefs because I might be wrong."
> Bertrand Russell

Dear Tony,

I'm sorry, but it didn't seem very convincing the first time.

The notion that bicyclists are not moving their upper bodies (or, to
be more accurate, using the muscles of their upper bodies) is
strange.

Consider the forces on the handlebars as you chug up a steep slope
with flexed arms.

Or consider trying to chug up that slope with only the tips of your
forefingers touching the bars for insignificant steering movements.

Or replace the metal handlebars with some springs strong enough to
allow steering, but flexible enough to show what kind of forces your
upper body is putting on the bars.

Cheers,

Carl Fogel

[Tony Raven[_2_]]

wrote in
ups.com:

> On Sep 8, 2:52 pm, Tony Raven > wrote:
>> wrote in news:1189282212.500032.53880
>> @y42g2000hsy.googlegroups.com:
>>
>>
>>
>> > Why would pedaling and putting the power through transmission
>> > losses be more efficient/effective/et cetera than just climbing a
>> > ladder? How does enforcing a much narrower range of speed and
>> > cadence improve things?
>>
>> Go back and read my previous response to you about upper body
>> movement for your answer.
>>
>> --
>> Tony
>>
>> " I would never die for my beliefs because I might be wrong."
>> Bertrand Russell
>
> Dear Tony,
>
> I'm sorry, but it didn't seem very convincing the first time.
>
> The notion that bicyclists are not moving their upper bodies (or, to
> be more accurate, using the muscles of their upper bodies) is
> strange.
>

You misunderstand the physics of the situation. Its nothing to do with
upper body muscle use, its to do with upper body vertical movement (think
potential energy). Lifting your body upwards with every step consumes
energy, having it fall back down at the end of every step doesn't recover
that energy (unlike the downstroke of the pedal under body weight while
standing on the pedals). The energy loss walking will almost certainly
be through the leg muscles having to work harder. As I said, try walking
without having your upper body move up and down.


--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Ryan Cousineau]

In article >, (Tom Keats)
wrote:

> In article >,
> Tony Raven > writes:
> > wrote in
> > oups.com:
> >>
> >> Once the feet travel as far in a circle as they would while walking,
> >> you're at an overall effective 1-to-1 ratio, and it's hard to come up
> >> with an explanation why this would be more effective than pushing the
> >> bike up the same slope with the natural walking motion.

> I'll tell ya this much -- I am so sick & tired of
> only being able to get 14-28T 6-spd freewheels.
> I wish I could get at least a 32.

Change out your 6-speed for a 7-speed Megarange. Unless you currently
have a set of indexed shifters you're loath to switch to the friction
setting, there's no downside.

Or maybe a chain you're very fond of,

--
Ryan Cousineau http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

[[email protected]]

On Sep 9, 3:47 am, (Tom Keats) wrote:
> In article . com>,
> writes:
>
> > Dear Artemisia,
>
> > I suspect that rider would go much faster up Fargo Street if he simply
> > walked up it, pushing his bike, with the same amount of effort--he's
> > heaving with all his might with every pedal stroke, barely able to
> > keep the pedals moving past the dead spots.
>
> ^^^^^^^^^^
>
> What causes those "dead spots" anyways?
>
> Is it physiological, or mechanical, or both,
> or neither?
>
> If (the legs of) a rider going up a steep grade
> experiences dead spots, it occurs to me that the
> drivers on a steam locomotive going up a steep
> grade might also experience similar dead spots.
>
> Anyways, I rather dislike those dead spots.
>
> cheers,
> Tom
>
> --
> Nothing is safe from me.
> I'm really at:
> tkeats curlicue vcn dot bc dot ca

Dear Tom,

If you're sitting, your hips are fixed on the bicycle seat relative to
the pedals, just like your locomotive example, and the same thing
happens. The connecting rod ofn of your leg cannot push with much
effect against the pedal at top dead center, just as a car engine's
connecting rod can't push with much effect on a piston at top dead
center.

The car engine uses its massive flywheel effect to "coast" past tdc.

The bicyclist simply uses the extra joints (hip, knee, ankle) in his
wiggle-able leg and its faint momentum to nudge the pedals past top
and bottom dead center.

Just how faint the momentum and available leverage is can be
demonstrated by stopping on a hill in a modest gear and trying to get
going again with pedals in an awkward position--you're stuck until you
spin the pedal back through the freewheel to a position with more
overall leverage.

This is one reason that we stand up to pedal when the going gets
tough. By standing, we allow our hips to move forward and backward and
also side to side, as we hunt for a better angle. Another reason for
standing is that it straightens our posture closer to the erect and
natural walking-running stance--your muscles and joints combine to
work better when you're upright than when you're in the bicyclist's
normal seated semi-crouching posture.

Here's a nice graph of the forces actually measured at the pedal that
illustrates the dead spots:

http://www.analyticcycling.com/PedalForcesAtPedal_Page.html

Here's a Robert Chung chart of Kautz's data for torque on the pedal:

http://anonymous.coward.free.fr/rbr/kautz.png

As for locomotives, they usually get around the dead spots by having
two drive shafts arranged so that they're never both at a dead spot.
Even single-cylinder engines get past the dead spots by simply
"coasting" over the dead spots with massive flywheel momentum.

Unfortunately, the two drive shafts of a bicycle are arranged so that
they hit top and bottom dead center at the same time, and bicycles
with freewheels have scarcely any flywheel effect.

Our legs have no natural flywheel action and stop spinning as soon as
we stop trying to pedal--it takes constant power to churn those big
chunks of meat and bone up and donwn.

The bicycle crank and pedals have scarcely any flywheel effect, being
extremely light compared to the mass of the bike and rider and
extremely slow. At a frantic 120 rpm with a 175 mm crank, the pedals
move in a circle at just under 5 mph.

Cheers,

Carl Fogel

[Tony Raven[_2_]]

wrote in news:1189406557.259000.67980
@r34g2000hsd.googlegroups.com:

>
> Unfortunately, the two drive shafts of a bicycle are arranged so that
> they hit top and bottom dead center at the same time, and bicycles
> with freewheels have scarcely any flywheel effect.
>

There was a design of crank where the crank could move a few degrees
relative to the chainwheel so that taking it over TDC was made easier.
They made great claims about efficiency improvements IIRC but they don't
seem to have survived the test of real life.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tom Keats]

In article >,
Ryan Cousineau > writes:
> In article >, (Tom Keats)
> wrote:
>
>> In article >,
>> Tony Raven > writes:
>> > wrote in
>> > oups.com:
>> >>
>> >> Once the feet travel as far in a circle as they would while walking,
>> >> you're at an overall effective 1-to-1 ratio, and it's hard to come up
>> >> with an explanation why this would be more effective than pushing the
>> >> bike up the same slope with the natural walking motion.
>
>> I'll tell ya this much -- I am so sick & tired of
>> only being able to get 14-28T 6-spd freewheels.
>> I wish I could get at least a 32.
>
> Change out your 6-speed for a 7-speed Megarange.

Who's got 'em? Everywhere I've gone when needing to
update my freewheel, only has those steenkin' 6-spd
14-28s. Sometimes I feel like drop-kickin' 'em into
the next universe (or at least, Burnaby.) No doubt
they'd eventually return by similar means.

> Unless you currently
> have a set of indexed shifters you're loath to switch to the friction
> setting, there's no downside.

Heh. I took out the clicks on my thumbies in order to
have friction shifting.

> Or maybe a chain you're very fond of,

I'm not very fond of my current Z Chain. Which is
also all you can get when all you can get is an
all-you-can-get 14-28. :-p

Well, I can always resort to the inner ring if I'd
ever really have to. The middle ring and the 28T
generally gets me up most of the local humps. At
least, the 10%+ ones ;-)

I just dislike the ignominy of having to shift to the
granny ring. Having a 32 or 34 back there while
staying in the middle ring, is comforting to my ego.

And when coming home from a hard-working shift of
hand-bombing freight out of shipping containers,
and subsequently grinding up the South Hill, it'd
be nice to be able to take it a little easy. Maybe
even drop my cadence, and pleasantly mash in somewhat
lower gears a little.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Peter Clinch]

Clive George wrote:

> Yes, pushing the trike isn't good. So you don't do it.

Was wondering about that, and it struck me that pulling it with a bit of
tape might actually work. It might not, of course, especially if the
steering wants to lock sideways.

> It's a different
> approach - rather than walking, you stop, relax, then ride again. Or
> indeed ride _really_ slowly - which you can, because there's no need for
> balancing.

The only clear problem is the extra time that might involve. I prefer
to get walking rather than wait until I can pedal on, but that's me and
isn't necessarily anyone else...

>
>> I'm trying to figure out if the trike is an advantage or an
>> unnecessary bother on the morning commute.
>
> I think the only way you'll find it out is by trying it. I reckon the
> trike will be less efficient than the bike, but other factors may make
> it more effective for you.

<aol> Yup! </aol>

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Peter Clinch]

Tony Raven wrote:
> Simon Brooke > wrote in
> :
>
>> Bikes have an effective lower limit speed - the speed at which you can
>> no longer balance and stay upright.
>
> There is another limit which is the ability to keep the front wheel on the
> ground and not loop out backwards.

Assuming you're on one of those ridiculous top-heavy "upright"
contraptions, that is[1]... ;-)

Pete.

[1] though it's never been an issue on the 8 Freight!
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Tony Raven[_2_]]

Peter Clinch > wrote in
:
>
> Assuming you're on one of those ridiculous top-heavy "upright"
> contraptions, that is[1]... ;-)

1 million lemmings can't be wrong ;-)

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tom]

Tom Keats > wrote:
> In article >,
> Ryan Cousineau > writes:
>>
>> Change out your 6-speed for a 7-speed Megarange.
>
> Who's got 'em? Everywhere I've gone when needing to
> update my freewheel, only has those steenkin' 6-spd
> 14-28s.

SJS have them:
http://www.sjscycles.co.uk/cid/PQSK7BAVQ3NCA2I9UEJ2OZ4WYGP2NPMM/category-Freewheels-7-speed-79.htm

Tom
--
Return address is dead. Real address is at
http://www.happy-penguin.info/address.jpg

[Roger Merriman]

Julian Gallop > wrote:

> Tony Raven wrote:
> > gary2006uk > wrote in
> > oups.com:
> >
> >
> >>cycling up steep hills is less efficient than walking.ive seen many
> >>mountain bikers riding,legs spinning round,hardly moving,whilst
> >>walking i have also passed bikers on the mountains.ive even seen
> >>cyclists in very low gear on the road,in too low a gear,legs going
> >>round like mad,hardly moving,very innefficient,one turn on my gear on
> >>a racing bike leaves them standing.i think some of them dont want to
> >>put any hard effort into cycling.ive also seen bikers on low gear
> >>dawdling along,no physical effort being used,they cant be benifiting
> >>physicaly in fitness riding that slow.god forbid if they ended up on a
> >>hill on a cycle track.
> >>
> >
> >
> > You've mixed up lots of things that have nothing to do with efficiency
> > and some that do and you have the wrong way round. For example spinning
> > quickly is more, not less, efficient than your "one turn on my gear".
> > Speed has nothing to do with efficiency unless you are starting to go
> > fast enough to introduce air resistance. Those fast spinning cyclists
> > you deride are probably getting up that hill far more efficiently than
> > your wasteful technique.
> >
> I think that when the gear becomes really low, the effort of rotating
> the legs many times over a short distance becomes significant. Whereas
> with walking, the stride length is not decreased very much.
>
> Julian Gallop

no walk up a steep hill and your stride is much less, by steep i mean
30% and over.

you also have to shift your weight, both are done much more automaticly
than on a bike, where one is more aware of it.

roger
--
www.rogermerriman.com

[[email protected]]

The book, "Bicycling Science" addresses this exact problem. They try
to figure out at what gradient walking becomes more efficient than
cycling. I think the figure they arrived at was around twenty percent
and they confirmed this with actual evidence--for steep and/or rough
routes, cyclists and runners will frequently take about the same
amount of time to complete the course. If you think about it, as the
grade gets steeper, more and more energy is put into simply overcoming
the force of gravity. Meanwhile, maximum speed drops so that the
raised gearing and lower frictional forces that normally give the
bicycle such an advantage are no longer a factor.

On Sep 6, 7:09 pm, Artemisia > wrote:
> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?
>
> I'm thinking perhaps the only advantage of trying to pedal up my hills
> is the inconvenience of trying to stand up out of a recumbent...
>
> EFR
> Ile de France

[Alan Braggins]

In article >, Tony Raven wrote:
>
>There was a design of crank where the crank could move a few degrees
>relative to the chainwheel so that taking it over TDC was made easier.
>They made great claims about efficiency improvements IIRC but they don't
>seem to have survived the test of real life.

Rotor seems to still be going, though they do make other products
(now including a more conventional crankset).
http://www.roadcyclinguk.com/news/article/mps/UAN/1611/V/1/SP/

Their new stem was announced fairly recently
http://www.roadcyclinguk.com/news/article/mps/UAN/2542/V/1/SP/

Reviews seem to say the dead-spot eliminating cranks do work, but that
it's not clear whether it's worth the extra cost/weight/complexity.
http://www.cyclingnews.com/tech.php?id=tech/2006/reviews/rotor_rsx4_mtb
http://www.bikemagic.com/news/article/mps/UAN/3966/

[[email protected]]

On 9 Sep, 09:44, Tony Raven > wrote:
> (Tom Keats) wrote :
>
>
>
> > Ah, but when riding a diamond-frame upright bike up a steep hump,
> > especially if the bike is heavily rearward laden, the front wheel
> > tends to lift up, and a lot of upper body effort is involved in
> > just keeping the front wheel down on the ground. That's what
> > MTB bar-ends are meant for.
>
> Yes, as I've said multiple times before in this thread, we can all dream
> up scenarios where one is better than the other but the basic starting
> point is still that cycling is more efficient than walking before you add
> in other factors such as steps.....

I don't think you're right, Tony. From experience of being faster on
foot than a cyclist up some hills in the South Downs (and she's fitter
than me), it seems pretty clear that there is a gradient above which
it's more efficient to walk/run. As we were both maxed out in terms of
energy expenditure (we were racing!) that would imply to me that both
efficiency and effectiveness were better for walking.

Also have a look at this article: http://www.springerlink.com/content/bt3tm8ckrjt4fg54/

--

TimP

[Tony Raven[_2_]]

wrote in
ups.com:
>
> I don't think you're right, Tony. From experience of being faster on
> foot than a cyclist up some hills in the South Downs (and she's fitter
> than me), it seems pretty clear that there is a gradient above which
> it's more efficient to walk/run. As we were both maxed out in terms of
> energy expenditure (we were racing!) that would imply to me that both
> efficiency and effectiveness were better for walking.
>
> Also have a look at this article:
> http://www.springerlink.com/content/bt3tm8ckrjt4fg54/
>

I've only had time for a very brief scan of the paper but it seems to be
saying there is a small zone in which walking can be more efficient than
cycling. This is at higher gradients and velocities below 1m/s or 2.25mph
(and above 0.1m/s) - a velocity below which most people cannot stay
balanced on a bicycle anyway. Above that speed Fig 2b seems to indicate,
subject to further study, that cycling is the most efficient.

I may change my mind when I've had time to read it properly.


--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[[email protected]]

On 10 Sep, 15:01, Tony Raven > wrote:
> wrote roups.com:
>
>
>
> > I don't think you're right, Tony. From experience of being faster on
> > foot than a cyclist up some hills in the South Downs (and she's fitter
> > than me), it seems pretty clear that there is a gradient above which
> > it's more efficient to walk/run. As we were both maxed out in terms of
> > energy expenditure (we were racing!) that would imply to me that both
> > efficiency and effectiveness were better for walking.
>
> > Also have a look at this article:
> >http://www.springerlink.com/content/bt3tm8ckrjt4fg54/
>
> I've only had time for a very brief scan of the paper but it seems to be
> saying there is a small zone in which walking can be more efficient than
> cycling. This is at higher gradients and velocities below 1m/s or 2.25mph
> (and above 0.1m/s) - a velocity below which most people cannot stay
> balanced on a bicycle anyway. Above that speed Fig 2b seems to indicate,
> subject to further study, that cycling is the most efficient.
>
> I may change my mind when I've had time to read it properly.

Well, as you wrote before:

Tony Raven wrote:
> Efficiency is normally taken as the energy needed to travel a distance, not
> speed otherwise a Hummer would be classed as more efficient than a bicycle.

Indeed.

The rest of the article describes the most efficient method of
travelling up different inclines. Walking is described as being the
most efficient above ~15%.

[Roger Merriman]

Tony Raven > wrote:

> wrote in
> ups.com:
> >
> > I don't think you're right, Tony. From experience of being faster on
> > foot than a cyclist up some hills in the South Downs (and she's fitter
> > than me), it seems pretty clear that there is a gradient above which
> > it's more efficient to walk/run. As we were both maxed out in terms of
> > energy expenditure (we were racing!) that would imply to me that both
> > efficiency and effectiveness were better for walking.
> >
> > Also have a look at this article:
> > http://www.springerlink.com/content/bt3tm8ckrjt4fg54/
> >
>
> I've only had time for a very brief scan of the paper but it seems to be
> saying there is a small zone in which walking can be more efficient than
> cycling. This is at higher gradients and velocities below 1m/s or 2.25mph
> (and above 0.1m/s) - a velocity below which most people cannot stay
> balanced on a bicycle anyway. Above that speed Fig 2b seems to indicate,
> subject to further study, that cycling is the most efficient.
>
that would seem to match with my experance. this said the window is
small.

> I may change my mind when I've had time to read it properly.

roger
--
www.rogermerriman.com

[Ryan Cousineau]

In article >,
(Tom Keats) wrote:

> In article >,
> Ryan Cousineau > writes:
> > In article >, (Tom Keats)
> > wrote:
> >
> >> In article >,
> >> Tony Raven > writes:
> >> > wrote in
> >> > oups.com:
> >> >>
> >> >> Once the feet travel as far in a circle as they would while walking,
> >> >> you're at an overall effective 1-to-1 ratio, and it's hard to come up
> >> >> with an explanation why this would be more effective than pushing the
> >> >> bike up the same slope with the natural walking motion.
> >
> >> I'll tell ya this much -- I am so sick & tired of
> >> only being able to get 14-28T 6-spd freewheels.
> >> I wish I could get at least a 32.
> >
> > Change out your 6-speed for a 7-speed Megarange.
>
> Who's got 'em? Everywhere I've gone when needing to
> update my freewheel, only has those steenkin' 6-spd
> 14-28s. Sometimes I feel like drop-kickin' 'em into
> the next universe (or at least, Burnaby.) No doubt
> they'd eventually return by similar means.

!? Hm. Try phoning Sports Junkies in Port Moody, and if Bikes on the
Drive doesn't have it, they're missing their market.

Otherwise, the Internet has lots of them.

But that's weird: the 11-34 7s should be one of the most common
freewheels around.

--
Ryan Cousineau http://www.wiredcola.com/
"I don't want kids who are thinking about going into mathematics
to think that they have to take drugs to succeed." -Paul Erdos

[Tony Raven[_2_]]

wrote in
oups.com:
>
> Well, as you wrote before:
>
> Tony Raven wrote:
>> Efficiency is normally taken as the energy needed to travel a
>> distance, not speed otherwise a Hummer would be classed as more
>> efficient than a bicycle.

You are misinterpreting things rather a lot. I said speed is not the same
as efficiency which is very different from saying that walking is only more
efficient, according to this paper, over a narrow range of (low) speeds.

>
> Indeed.
>
> The rest of the article describes the most efficient method of
> travelling up different inclines. Walking is described as being the
> most efficient above ~15%.
>

They also point out that there is an unexpectedly high energy cost of the
gradient in their cycle experiments that they cannot explain. Having
dismissed possible ones such as rolling resistance and air resistance they
come down to inefficient pedaling on a slope or the efforts to control the
bike on a short narrow treadmill.




--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[[email protected]]

On 10 Sep, 16:59, Tony Raven > wrote:
> wrote groups.com:
>
>
>
> > Well, as you wrote before:
>
> > Tony Raven wrote:
> >> Efficiency is normally taken as the energy needed to travel a
> >> distance, not speed otherwise a Hummer would be classed as more
> >> efficient than a bicycle.
>
> You are misinterpreting things rather a lot. I said speed is not the same
> as efficiency which is very different from saying that walking is only more
> efficient, according to this paper, over a narrow range of (low) speeds.

No I'm not. You've repeatedly posted that cycling is inherently more
efficient, with the caveat that you're not trying to cycle up stairs
etc. Others, including myself, posted that they have personal
experience of situations where pushing the bike or walking was more
efficient/effective. The paper showed evidence of where this can be
the case.

The situation I referred to where I was faster on foot than a friend
on a bike was on a hill that was sufficiently steep that I was
basically walking rather than running - and the cyclist was going
slower. Agreed, if she had been more powerful she might have been able
to get some momentum going, but she couldn't. Looks like she was stuck
in that area of the graph where walking was more efficient.

[_[_2_]]

On Mon, 10 Sep 2007 16:24:29 -0000, wrote:

> On 10 Sep, 16:59, Tony Raven > wrote:
>> wrote groups.com:
>>
>>
>>
>>> Well, as you wrote before:
>>
>>> Tony Raven wrote:
>>>> Efficiency is normally taken as the energy needed to travel a
>>>> distance, not speed otherwise a Hummer would be classed as more
>>>> efficient than a bicycle.
>>
>> You are misinterpreting things rather a lot. I said speed is not the same
>> as efficiency which is very different from saying that walking is only more
>> efficient, according to this paper, over a narrow range of (low) speeds.
>
> No I'm not. You've repeatedly posted that cycling is inherently more
> efficient, with the caveat that you're not trying to cycle up stairs
> etc. Others, including myself, posted that they have personal
> experience of situations where pushing the bike or walking was more
> efficient/effective. The paper showed evidence of where this can be
> the case.
>
> The situation I referred to where I was faster on foot than a friend
> on a bike was on a hill that was sufficiently steep that I was
> basically walking rather than running - and the cyclist was going
> slower. Agreed, if she had been more powerful she might have been able
> to get some momentum going, but she couldn't. Looks like she was stuck
> in that area of the graph where walking was more efficient.

Looks as though you are saying that Tony's exception doesn't include your
situation - similar to arguing that one bit of the split hair is bigger.

[[email protected]]

On 10 Sep, 17:32, _ >
wrote:
> On Mon, 10 Sep 2007 16:24:29 -0000, wrote:
> > On 10 Sep, 16:59, Tony Raven > wrote:
> >> wrote groups.com:
>
> >>> Well, as you wrote before:
>
> >>> Tony Raven wrote:
> >>>> Efficiency is normally taken as the energy needed to travel a
> >>>> distance, not speed otherwise a Hummer would be classed as more
> >>>> efficient than a bicycle.
>
> >> You are misinterpreting things rather a lot. I said speed is not the same
> >> as efficiency which is very different from saying that walking is only more
> >> efficient, according to this paper, over a narrow range of (low) speeds.
>
> > No I'm not. You've repeatedly posted that cycling is inherently more
> > efficient, with the caveat that you're not trying to cycle up stairs
> > etc. Others, including myself, posted that they have personal
> > experience of situations where pushing the bike or walking was more
> > efficient/effective. The paper showed evidence of where this can be
> > the case.
>
> > The situation I referred to where I was faster on foot than a friend
> > on a bike was on a hill that was sufficiently steep that I was
> > basically walking rather than running - and the cyclist was going
> > slower. Agreed, if she had been more powerful she might have been able
> > to get some momentum going, but she couldn't. Looks like she was stuck
> > in that area of the graph where walking was more efficient.
>
> Looks as though you are saying that Tony's exception doesn't include your
> situation - similar to arguing that one bit of the split hair is bigger.

<sigh>

Tony's caveat was regarding unsuitable terrain like mud, gravel or
stairs - let's see: "boulder fields, scree slopes, deep snow,
overhanging rock faces" - none of which apply here. Anyway the
situation on the hill that I described is pretty much exactly the same
as the one described at the beginning of the thread (and repeated by
others throughout).

The paper indicates that, in terms of J/kg/m, above a certain gradient
the most efficient method of getting up the hill is to walk. It just
happens that the optimal speed for that to happen is - surprise! -
within the normal range of speed for walking. Well I never.

I guess the reason is because of the "dead spots" encountered when the
crank is at some angles, referred to elsewhere in the thread. I
further suppose it's because when you're having to cycle slowly
because of the gradient, you can't use your momentum to carry through
these angles on the crank that are biomechanically inefficient. A
racer would probably be able to produce a sufficient power output to
build up momentum, and thus avoid the problem.

[Tony Raven[_2_]]

wrote in
oups.com:
>
> No I'm not. You've repeatedly posted that cycling is inherently more
> efficient, with the caveat that you're not trying to cycle up stairs
> etc. Others, including myself, posted that they have personal
> experience of situations where pushing the bike or walking was more
> efficient/effective. The paper showed evidence of where this can be
> the case.
>
> The situation I referred to where I was faster on foot than a friend
> on a bike was on a hill that was sufficiently steep that I was
> basically walking rather than running - and the cyclist was going
> slower. Agreed, if she had been more powerful she might have been able
> to get some momentum going, but she couldn't. Looks like she was stuck
> in that area of the graph where walking was more efficient.
>

You are doing it again - confusing the relative speeds at which activity
takes place as evidence of efficiency. If another friend had run up the
slope and beaten both of you, by your measure they would have been more
efficient whereas the paper you are citing rules out running completely as
an efficient way of hill climbing. I repeat the relative speeds at which
you and your friend went up that slope are irrelevant as an indicator of
efficiency.

And I doubt she was stuck in the area on the graph where walking was more
efficient as a) very few cyclists can balance on a hill at speeds of 2mph
or less and b) if you were walking faster than that then you were
definitely in the region of the graph where cycling is more efficient.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Tony Raven[_2_]]

wrote in
ups.com:

>
> I guess the reason is because of the "dead spots" encountered when the
> crank is at some angles, referred to elsewhere in the thread. I
> further suppose it's because when you're having to cycle slowly
> because of the gradient, you can't use your momentum to carry through
> these angles on the crank that are biomechanically inefficient. A
> racer would probably be able to produce a sufficient power output to
> build up momentum, and thus avoid the problem.
>

No need to guess, the authors discuss it. After ruling out air and
rolling resistance they say:

"Only other two potential reasons can be claimed to explain the
relatively high vertical cost of gradient cycling: (1) a lower
transmission efficiency than W (walking) and R (running), as caused, for
instance, by an impaired push on the pedals on steep gradients, and/or
(2) a notable increase in co-contractions of postural muscles, necessary
to stabilize and control the bicycle while riding on a narrow and short
treadmill at slow speeds."

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[[email protected]]

On 10 Sep, 18:13, Tony Raven > wrote:
> I repeat the relative speeds at which
> you and your friend went up that slope are irrelevant as an indicator of
> efficiency.

That's not necessarily true. We were both likely putting out the same
amount of power, as we can run/cycle at similar speeds - I don't know,
150W. We were racing up the hill. My 150W got me higher up the hill in
a given time than hers did, so I consumed less energy per unit height
than she did.

I appreciate, though, that if running rather than cycling enabled me
to produce more power, that would be a difference in effectiveness
rather than efficiency.

Anyway I'm going out to run up Primrose Hill :P

[_[_2_]]

On Mon, 10 Sep 2007 17:28:15 -0000, wrote:


> That's not necessarily true. We were both likely putting out the same
> amount of power, as we can run/cycle at similar speeds - I don't know,
> 150W. We were racing up the hill. My 150W got me higher up the hill in
> a given time than hers did, so I consumed less energy per unit height
> than she did.
>

Well, that's comparing apples with the kind of apple spelt "O-R-A-N-G-E".

[[email protected]]

On 10 Sep, 12:55, wrote:
> The book, "Bicycling Science" addresses this exact problem. They try
> to figure out at what gradient walking becomes more efficient than
> cycling. I think the figure they arrived at was around twenty percent
> and they confirmed this with actual evidence--for steep and/or rough
> routes, cyclists and runners will frequently take about the same
> amount of time to complete the course. If you think about it, as the
> grade gets steeper, more and more energy is put into simply overcoming
> the force of gravity. Meanwhile, maximum speed drops so that the
> raised gearing and lower frictional forces that normally give the
> bicycle such an advantage are no longer a factor.
>
> On Sep 6, 7:09 pm, Artemisia > wrote:
>
>
>
> > Peter Clinch wrote:
>
> > > I recall one incident when a pal and I were taking our MTBs up a fairly
> > > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> > So isn't it actually more efficient energy use to walk uphill than to
> > pedal, even if you do have unimaginably low gears and no topple-over on
> > a trike?
>
> > I'm thinking perhaps the only advantage of trying to pedal up my hills
> > is the inconvenience of trying to stand up out of a recumbent...


Examine the limiting case:-

With the lowest possible gearing, namely Infinity to One
(or zero inches if you like), your legs will
spin round and round expending energy and no progress will
be made. The efficienty will be zero - the losses 100%.

Then imagine changing the gearing slightly so that some
progress is made the losses are then slightly less than
100%.

Raising the gearing further will eventually
reach the same efficiency as walking.

As the gearing is raised even further the efficiency will be
greater than that of walking and we are in the realm
of the normal bicycle.

I think therefore that

"> > So isn't it actually more efficient energy use to walk uphill
than to
> > pedal, even if you do have unimaginably low gears and no topple-over on
> > a trike?"

is indeed true.


Douglas.

[Paul O]

wrote:
> On 10 Sep, 12:55, wrote:
>> The book, "Bicycling Science" addresses this exact problem. They try
>> to figure out at what gradient walking becomes more efficient than
>> cycling. I think the figure they arrived at was around twenty percent
>> and they confirmed this with actual evidence--for steep and/or rough
>> routes, cyclists and runners will frequently take about the same
>> amount of time to complete the course. If you think about it, as the
>> grade gets steeper, more and more energy is put into simply overcoming
>> the force of gravity. Meanwhile, maximum speed drops so that the
>> raised gearing and lower frictional forces that normally give the
>> bicycle such an advantage are no longer a factor.
>>
>> On Sep 6, 7:09 pm, Artemisia > wrote:
>>
>>
>>
>>> Peter Clinch wrote:
>>> > I recall one incident when a pal and I were taking our MTBs up a fairly
>>> > steep grassy field. I got bored at walking pace, and decided I'd walk.
>>> > While walking, I soon overtook my pal, still spinning happily in 1st...
>>> So isn't it actually more efficient energy use to walk uphill than to
>>> pedal, even if you do have unimaginably low gears and no topple-over on
>>> a trike?
>>> I'm thinking perhaps the only advantage of trying to pedal up my hills
>>> is the inconvenience of trying to stand up out of a recumbent...
>
>
> Examine the limiting case:-
>
> With the lowest possible gearing, namely Infinity to One
> (or zero inches if you like), your legs will
> spin round and round expending energy and no progress will
> be made. The efficienty will be zero - the losses 100%.
>
> Then imagine changing the gearing slightly so that some
> progress is made the losses are then slightly less than
> 100%.
>
> Raising the gearing further will eventually
> reach the same efficiency as walking.
>
> As the gearing is raised even further the efficiency will be
> greater than that of walking and we are in the realm
> of the normal bicycle.
>
> I think therefore that
>
> "> > So isn't it actually more efficient energy use to walk uphill
> than to
>>> pedal, even if you do have unimaginably low gears and no topple-over on
>>> a trike?"
>
> is indeed true.
>
>
> Douglas.
>
Douglas,
Brilliant! Best post of the month!

--

Paul D Oosterhout
I work for SAIC (but I don't speak for SAIC)

[[email protected]]

On 10 Sep, 19:12, _ >
wrote:
> On Mon, 10 Sep 2007 17:28:15 -0000, wrote:
> > That's not necessarily true. We were both likely putting out the same
> > amount of power, as we can run/cycle at similar speeds - I don't know,
> > 150W. We were racing up the hill. My 150W got me higher up the hill in
> > a given time than hers did, so I consumed less energy per unit height
> > than she did.
>
> Well, that's comparing apples with the kind of apple spelt "O-R-A-N-G-E".

Only if you're *S*T*U*P*I*D*

[_[_2_]]

On Mon, 10 Sep 2007 20:54:08 -0000, wrote:

> On 10 Sep, 19:12, _ >
> wrote:
>> On Mon, 10 Sep 2007 17:28:15 -0000, wrote:
>>> That's not necessarily true. We were both likely putting out the same
>>> amount of power, as we can run/cycle at similar speeds - I don't know,
>>> 150W. We were racing up the hill. My 150W got me higher up the hill in
>>> a given time than hers did, so I consumed less energy per unit height
>>> than she did.
>>
>> Well, that's comparing apples with the kind of apple spelt "O-R-A-N-G-E".
>
> Only if you're *S*T*U*P*I*D*

I was referring to the apparent drawing of a conclusion from two situations
that differ in more than one relevant characteristic.

[[email protected]]

On 10 Sep, 20:33, Paul O > wrote:
> wrote:
> > On 10 Sep, 12:55, wrote:
> >> The book, "Bicycling Science" addresses this exact problem. They try
> >> to figure out at what gradient walking becomes more efficient than
> >> cycling. I think the figure they arrived at was around twenty percent
> >> and they confirmed this with actual evidence--for steep and/or rough
> >> routes, cyclists and runners will frequently take about the same
> >> amount of time to complete the course. If you think about it, as the
> >> grade gets steeper, more and more energy is put into simply overcoming
> >> the force of gravity. Meanwhile, maximum speed drops so that the
> >> raised gearing and lower frictional forces that normally give the
> >> bicycle such an advantage are no longer a factor.
>
> >> On Sep 6, 7:09 pm, Artemisia > wrote:
>
> >>> Peter Clinch wrote:
> >>> > I recall one incident when a pal and I were taking our MTBs up a fairly
> >>> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> >>> > While walking, I soon overtook my pal, still spinning happily in 1st...
> >>> So isn't it actually more efficient energy use to walk uphill than to
> >>> pedal, even if you do have unimaginably low gears and no topple-over on
> >>> a trike?
> >>> I'm thinking perhaps the only advantage of trying to pedal up my hills
> >>> is the inconvenience of trying to stand up out of a recumbent...
>
> > Examine the limiting case:-
>
> > With the lowest possible gearing, namely Infinity to One
> > (or zero inches if you like), your legs will
> > spin round and round expending energy and no progress will
> > be made. The efficienty will be zero - the losses 100%.
>
> > Then imagine changing the gearing slightly so that some
> > progress is made the losses are then slightly less than
> > 100%.
>
> > Raising the gearing further will eventually
> > reach the same efficiency as walking.
>
> > As the gearing is raised even further the efficiency will be
> > greater than that of walking and we are in the realm
> > of the normal bicycle.
>
> > I think therefore that
>
> > "> > So isn't it actually more efficient energy use to walk uphill
> > than to
> >>> pedal, even if you do have unimaginably low gears and no topple-over on
> >>> a trike?"
>
> > is indeed true.
>
> > Douglas.
>
> Douglas,
> Brilliant! Best post of the month!
>

Illumination of the month I might go for.

Brilliant! Not at all. I was taught that at school mumble
mumble mumble years ago.

"The important thing is asking the right questions."
Me.

[[email protected]]

On 11 Sep, 01:36, wrote:
> On 10 Sep, 20:33, Paul O > wrote:
>
>
>
>
>
> > wrote:
> > > On 10 Sep, 12:55, wrote:
> > >> The book, "Bicycling Science" addresses this exact problem. They try
> > >> to figure out at what gradient walking becomes more efficient than
> > >> cycling. I think the figure they arrived at was around twenty percent
> > >> and they confirmed this with actual evidence--for steep and/or rough
> > >> routes, cyclists and runners will frequently take about the same
> > >> amount of time to complete the course. If you think about it, as the
> > >> grade gets steeper, more and more energy is put into simply overcoming
> > >> the force of gravity. Meanwhile, maximum speed drops so that the
> > >> raised gearing and lower frictional forces that normally give the
> > >> bicycle such an advantage are no longer a factor.
>
> > >> On Sep 6, 7:09 pm, Artemisia > wrote:
>
> > >>> Peter Clinch wrote:
> > >>> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > >>> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > >>> > While walking, I soon overtook my pal, still spinning happily in 1st...
> > >>> So isn't it actually more efficient energy use to walk uphill than to
> > >>> pedal, even if you do have unimaginably low gears and no topple-over on
> > >>> a trike?
> > >>> I'm thinking perhaps the only advantage of trying to pedal up my hills
> > >>> is the inconvenience of trying to stand up out of a recumbent...
>
> > > Examine the limiting case:-
>
> > > With the lowest possible gearing, namely Infinity to One
> > > (or zero inches if you like), your legs will
> > > spin round and round expending energy and no progress will
> > > be made. The efficienty will be zero - the losses 100%.
>
> > > Then imagine changing the gearing slightly so that some
> > > progress is made the losses are then slightly less than
> > > 100%.
>
> > > Raising the gearing further will eventually
> > > reach the same efficiency as walking.
>
> > > As the gearing is raised even further the efficiency will be
> > > greater than that of walking and we are in the realm
> > > of the normal bicycle.
>
> > > I think therefore that
>
> > > "> > So isn't it actually more efficient energy use to walk uphill
> > > than to
> > >>> pedal, even if you do have unimaginably low gears and no topple-over on
> > >>> a trike?"
>
> > > is indeed true.
>
> > > Douglas.
>
> > Douglas,
> > Brilliant! Best post of the month!
>
> Illumination of the month I might go for.
>
> Brilliant! Not at all. I was taught that at school mumble
> mumble mumble years ago.
>
> "The important thing is asking the right questions."
> Me.- Hide quoted text -

Bad form etc.

Brilliance is recognising this effect while not being able to
fix a puncture. (or anything else!!!!!!!!!!)
Sacre bleu!

e.g.
"EFR
Ile de France "

[CoyoteBoy]

On 10 Sep, 15:01, Tony Raven > wrote:
> wrote roups.com:
>
>
>
> > I don't think you're right, Tony. From experience of being faster on
> > foot than a cyclist up some hills in the South Downs (and she's fitter
> > than me), it seems pretty clear that there is a gradient above which
> > it's more efficient to walk/run. As we were both maxed out in terms of
> > energy expenditure (we were racing!) that would imply to me that both
> > efficiency and effectiveness were better for walking.
>
> > Also have a look at this article:
> >http://www.springerlink.com/content/bt3tm8ckrjt4fg54/
>
> I've only had time for a very brief scan of the paper but it seems to be
> saying there is a small zone in which walking can be more efficient than
> cycling. This is at higher gradients and velocities below 1m/s or 2.25mph
> (and above 0.1m/s) - a velocity below which most people cannot stay
> balanced on a bicycle anyway. Above that speed Fig 2b seems to indicate,
> subject to further study, that cycling is the most efficient.
>
> I may change my mind when I've had time to read it properly.
>
> --
> Tony
>
> " I would never die for my beliefs because I might be wrong."
> Bertrand Russell

I'm with you on this.

[[email protected]]

On 10 Sep, 23:58, _ >
wrote:
> On Mon, 10 Sep 2007 20:54:08 -0000, wrote:
> > On 10 Sep, 19:12, _ >
> > wrote:
> >> On Mon, 10 Sep 2007 17:28:15 -0000, wrote:
> >>> That's not necessarily true. We were both likely putting out the same
> >>> amount of power, as we can run/cycle at similar speeds - I don't know,
> >>> 150W. We were racing up the hill. My 150W got me higher up the hill in
> >>> a given time than hers did, so I consumed less energy per unit height
> >>> than she did.
>
> >> Well, that's comparing apples with the kind of apple spelt "O-R-A-N-G-E".
>
> > Only if you're *S*T*U*P*I*D*
>
> I was referring to the apparent drawing of a conclusion from two situations
> that differ in more than one relevant characteristic.

God, I thought Tony was patronising and dull, but in comparison with
you he's a breath of fresh air. Come back!

[[email protected]]

On Sep 10, 12:14 am, Tony Raven > wrote:
> wrote roups.com:
>
>
>
>
>
> > On Sep 8, 2:52 pm, Tony Raven > wrote:
> >> wrote in news:1189282212.500032.53880
> >> @y42g2000hsy.googlegroups.com:
>
> >> > Why would pedaling and putting the power through transmission
> >> > losses be more efficient/effective/et cetera than just climbing a
> >> > ladder? How does enforcing a much narrower range of speed and
> >> > cadence improve things?
>
> >> Go back and read my previous response to you about upper body
> >> movement for your answer.
>
> >> --
> >> Tony
>
> >> " I would never die for my beliefs because I might be wrong."
> >> Bertrand Russell
>
> > Dear Tony,
>
> > I'm sorry, but it didn't seem very convincing the first time.
>
> > The notion that bicyclists are not moving their upper bodies (or, to
> > be more accurate, using the muscles of their upper bodies) is
> > strange.
>
> You misunderstand the physics of the situation. Its nothing to do with
> upper body muscle use, its to do with upper body vertical movement (think
> potential energy). Lifting your body upwards with every step consumes
> energy, having it fall back down at the end of every step doesn't recover
> that energy (unlike the downstroke of the pedal under body weight while
> standing on the pedals). The energy loss walking will almost certainly
> be through the leg muscles having to work harder. As I said, try walking
> without having your upper body move up and down.
>
> --
> Tony
>
> " I would never die for my beliefs because I might be wrong."
> Bertrand Russell- Hide quoted text -
>
> - Show quoted text -

Dear Tony,

I think that you misunderstand the physics of walking up a steep
slope, where the rise and fall of level walking turns into more of a
stairstep than a sinusoidal motion.

Cheers,

Carl Fogel

[[email protected]]

On Sep 10, 1:14 am, Tony Raven > wrote:
> wrote in news:1189406557.259000.67980
> @r34g2000hsd.googlegroups.com:
>
>
>
> > Unfortunately, the two drive shafts of a bicycle are arranged so that
> > they hit top and bottom dead center at the same time, and bicycles
> > with freewheels have scarcely any flywheel effect.
>
> There was a design of crank where the crank could move a few degrees
> relative to the chainwheel so that taking it over TDC was made easier.
> They made great claims about efficiency improvements IIRC but they don't
> seem to have survived the test of real life.
>
> --
> Tony
>
> " I would never die for my beliefs because I might be wrong."
> Bertrand Russell

Dear Tony,

I suppose that it would be something like the independent Power Crank
(or possibly Rotor Crank--I get them mixed up), where the crank arms
can move independently.

It's hard to see how even letting each crank move independently will
help the dead spot, since the rotary crank still passes through it
with little or no power applied.

Aa treadle design like this might get around the dead spot (I'm not
sure), but as you say, it never survived the test of real life:

http://i9.tinypic.com/4taqys4.jpg

Cheers,

Carl Fogel

[Rob Morley]

In article om>,
says...

> Aa treadle design like this might get around the dead spot (I'm not
> sure), but as you say, it never survived the test of real life:
>
> http://i9.tinypic.com/4taqys4.jpg
>
All you need is some sort of ratcheted spring that winds up on the
highest torque part of the stroke then unwinds around the dead spot.
The fact that it hasn't been implemented suggests that it's a solution
looking for a problem.

[[email protected]]

On Sep 9, 3:47 am, (Tom Keats) wrote:
> In article . com>,
> writes:
>
> > Dear Artemisia,
>
> > I suspect that rider would go much faster up Fargo Street if he simply
> > walked up it, pushing his bike, with the same amount of effort--he's
> > heaving with all his might with every pedal stroke, barely able to
> > keep the pedals moving past the dead spots.
>
> ^^^^^^^^^^
>
> What causes those "dead spots" anyways?
>
> Is it physiological, or mechanical, or both,
> or neither?
>
> If (the legs of) a rider going up a steep grade
> experiences dead spots, it occurs to me that the
> drivers on a steam locomotive going up a steep
> grade might also experience similar dead spots.
>
> Anyways, I rather dislike those dead spots.
>
> cheers,
> Tom
>
> --
> Nothing is safe from me.
> I'm really at:
> tkeats curlicue vcn dot bc dot ca

Dear Tom,

Utterly off topic, but you mentioned locomotives and dead spots . . .

So here's a post about an 1894 steam-powered bicycle with a locomotive-
style transmission, complete with movie of a reconstruction chugging
along:

http://groups.google.com/group/rec.bicycles.tech/msg/2588df400d5ced14

Ch-ch-ch-cheers,

Carl Fogel

[Ben C]

On 2007-09-12, Rob Morley > wrote:
> In article om>,
> says...
>
>> Aa treadle design like this might get around the dead spot (I'm not
>> sure), but as you say, it never survived the test of real life:
>>
>> http://i9.tinypic.com/4taqys4.jpg
>>
> All you need is some sort of ratcheted spring that winds up on the
> highest torque part of the stroke then unwinds around the dead spot.

Or a fixed-gear bike.

[[email protected]]

On Sep 10, 3:42 pm, wrote:

> Our legs have no natural flywheel action and stop spinning as soon as
> we stop trying to pedal--it takes constant power to churn those big
> chunks of meat and bone up and donwn.

But obviously very very little power, as anyone who has ever broken a
chain or dropped a gear will know. It also takes power to lift a foot
up higher than ground level only to put it down again when walking.
Which do you think is a greater waste of power, and why? Have you any
quantitative estimates of either effect on which to base a comparison?

James

[Rob Morley]

In article >, Ben C
says...
> On 2007-09-12, Rob Morley > wrote:
> > In article om>,
> > says...
> >
> >> Aa treadle design like this might get around the dead spot (I'm not
> >> sure), but as you say, it never survived the test of real life:
> >>
> >> http://i9.tinypic.com/4taqys4.jpg
> >>
> > All you need is some sort of ratcheted spring that winds up on the
> > highest torque part of the stroke then unwinds around the dead spot.
>
> Or a fixed-gear bike.
>
What that does is use the flywheel effect of the rear wheel to pull your
legs past the dead spot, which you don't need anyway if you pedal in
circles rather than squares. What fixed wheel does not do is smooth the
power delivery to the wheel.

[POHB]

On 11 Sep, 01:36, wrote:
> > > Examine the limiting case:-
>
> > > With the lowest possible gearing, namely Infinity to One
> > > (or zero inches if you like), your legs will
> > > spin round and round expending energy and no progress will
> > > be made. The efficienty will be zero - the losses 100%.
>
> > > Then imagine changing the gearing slightly so that some
> > > progress is made the losses are then slightly less than
> > > 100%.
>
> > > Raising the gearing further will eventually
> > > reach the same efficiency as walking.
>
> > > As the gearing is raised even further the efficiency will be
> > > greater than that of walking and we are in the realm
> > > of the normal bicycle.
>
> > > I think therefore that
>
> > > "> > So isn't it actually more efficient energy use to walk uphill
> > > than to
> > >>> pedal, even if you do have unimaginably low gears and no topple-over on
> > >>> a trike?"
>
> > > is indeed true.

I think your reasoning is flawed as it assumes that walking efficiency
is constant for all speeds. Actually at zero speed walking is also
100% inneficient as you are spending energy keeping upright but making
no forward movement. As walking speed increases the efficiency also
increases, the same as cycling.

So, the question is how the two efficiency curves compare to each
other. If you plot efficiency on an increasing Y axis and speed on X,
which curve takes off most steeply and where (if ever) do they cross.
The concensus seems to be that the walking curve starts off more
steeply but the cycling curve crosses it at about normal walking pace
and then continues upwards.

[[email protected]]

On Sep 12, 1:22 am, " >
wrote:
> On Sep 10, 3:42 pm, wrote:
>
> > Our legs have no natural flywheel action and stop spinning as soon as
> > we stop trying to pedal--it takes constant power to churn those big
> > chunks of meat and bone up and donwn.
>
> But obviously very very little power, as anyone who has ever broken a
> chain or dropped a gear will know. It also takes power to lift a foot
> up higher than ground level only to put it down again when walking.
> Which do you think is a greater waste of power, and why? Have you any
> quantitative estimates of either effect on which to base a comparison?
>
> James

Dear James,

Dear James,

Let's consider a 33.3% grade and a rider whose weight and fitness
reduce him to using 1-to-1 overall gearing.

Obviously, some riders would need more gearing and others could use
higher gearing, but we need a specific example, and most posters would
consider a mile of 33.3% grade steep.

There are two ways to calculate slope as a percentage. In this case,
we mean a 33% grade where you gain 1 foot in height for every 3 feet
that you move forward and upward as measured by an odometer.

The other method of calculating slope as a percentage would gain 1
foot in height for every 3 _level_ feet forward and would call our
slope a 35.3% grade (1 / 2.83) instead of 33% (1 / 3.00). This
wouldn't matter much to the overall calculations, but it's best to
avoid confusion.

With 1-to-1 overall gearing, the foot travels just as far around the
pedal circle as the rear wheel moves forward. For a 2100 mm 700c tire
and a 175 mm crank, this means 20 x 38 gearing and a 350 mm high pedal
circle.

Pi * 350 mm gives an 1100 mm "stride" with each pedal cycle.

In other words, for each 1.1 meters up the 33.3% grade, you turn a
full pedal cycle, raising and lowering your left foot 350 mm relative
to its initial bottom dead center position on the 175 mm crank.

Here's a diagram with numbers:

http://i6.tinypic.com/6crrg3n.jpg

Half-way up the 1100 mm slope, the whole bicycle has risen 183 mm,
which is 33.3% of 550 mm.

Meanwhile, the left pedal has risen another 350 mm, from the bottom to
the top of the pedal cycle, so the pedal is 533 mm above its starting
position (183 + 350 = 533 mm total rise).

Then the left pedal descends back to the bottom of the pedal cycle,
reaching bottom dead center again at 1100 mm up the slope and dropping
166 mm from 533 mm down to 367 mm, which is 33.3% of 1100 mm.

In other words, the left foot rises much more sharply than the slope
for the first part of the pedal cycle.

Then it drops more gently about 6.5 inches from its highest point,
roughly the height of a stair step.

When walking, most people don't lift their feet as high as the step
_above_ the step that they plant their foot on, unless they're doing a
very strange goose-step.

Cheers,

Carl Fogel

[Tony Raven[_2_]]

wrote in
ups.com:

> In other words, the left foot rises much more sharply than the slope
> for the first part of the pedal cycle.
>
> Then it drops more gently about 6.5 inches from its highest point,
> roughly the height of a stair step.
>
> When walking, most people don't lift their feet as high as the step
> _above_ the step that they plant their foot on, unless they're doing a
> very strange goose-step.

Dearest Carl,

You've forgotten a significant factor in your estimations that makes your
conclusions wrong. When you lift your foot walking it takes energy to
do it. When you put it back down you don't regain that energy. On a
bicycle its different. The cranks are neutrally balanced if the weight
of your legs is the same. So when your left foot is going down, the
potential energy lost from its weight descending on the pedal is
transferred through the cranks to lift the weight of the right leg up.
To first order the energy expended in that revolution of the pedals is
only the energy needed to move the bike and rider up the slope and the
energy needed to overcome the friction in the bottom bracket and chain.
The energy component from the legs going round and round is to first
order negligible.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Ben C]

On 2007-09-13, Tony Raven > wrote:
> wrote in
> ups.com:
>
>> In other words, the left foot rises much more sharply than the slope
>> for the first part of the pedal cycle.
>>
>> Then it drops more gently about 6.5 inches from its highest point,
>> roughly the height of a stair step.
>>
>> When walking, most people don't lift their feet as high as the step
>> _above_ the step that they plant their foot on, unless they're doing a
>> very strange goose-step.
>
> Dearest Carl,
>
> You've forgotten a significant factor in your estimations that makes your
> conclusions wrong. When you lift your foot walking it takes energy to
> do it. When you put it back down you don't regain that energy. On a
> bicycle its different. The cranks are neutrally balanced if the weight
> of your legs is the same. So when your left foot is going down, the
> potential energy lost from its weight descending on the pedal is
> transferred through the cranks to lift the weight of the right leg up.

I'm not sure about this argument.

When you walk up steps you lift your leg up and then push down on the
step with it. The fact that your leg has weight means that you can push
down a little bit less hard. So you get the potential energy back in
spite of not having neutrally balanced cranks.

Actually of course your leg isn't really falling, if you're walking up
steps, but staying roughly where it is, while the rest of your body is
lifted up to join it on the next step. This doesn't really change
anything though: first you lift one leg to put it on the step in front
of you. Then you lift the weight of your body minus the weight of that
one leg to heave the rest of you up the step. So altogether you lifted
your whole weight up the step once, in two stages. No wasted lifting, at
least not in this basic picture of what's happening.

Another way of looking at it is this: suppose you rode the bike in such
a way that you lifted the up-leg with its own muscles instead of
allowing it to be pushed up by the pedal-- so on the upstroke your foot
hovered a tiny distance above the pedal at all times. Although you'd
have to put in a bit more energy to lift that leg, the leg that was
going down would go down with more force: whatever you were pushing with
_plus its own weight_. What you take from the up leg you give back to
the down leg. Whether the leg lifts itself or is lifted by the other leg
makes no difference, and for the purposes of the point being made here,
walking is just the same as cycling with up-leg self-lifting.

I'm not sure about Carl's argument either though. If you walk up steps
it doesn't make any difference to the energy expended as far as the
basic physics are concerned how high or shallow the steps are.

If walking up a slope is easier than riding up it (for the same weight,
Carl's 1:1 gear, etc.) then I think we need to look somewhere else for
the reason.

[Tony Raven[_2_]]

Ben C > wrote in
:

>
> I'm not sure about this argument.
>
> When you walk up steps you lift your leg up and then push down on the
> step with it. The fact that your leg has weight means that you can
> push down a little bit less hard. So you get the potential energy back
> in spite of not having neutrally balanced cranks.

That would be if you slid your foot onto the step but you don't, you lift
it above the step and then put it down. Likewise walking up a slope you
don't slide your foot up the slope but lift it off the surface, move it
up and then put it down again. Its the putting down bit that wastes
potential energy that is not wasted on a bike.

>
> I'm not sure about Carl's argument either though. If you walk up steps
> it doesn't make any difference to the energy expended as far as the
> basic physics are concerned how high or shallow the steps are.
>

It will matter unless the distance you lift your foot above the step
before putting it down is proportional to the step height. It is more
likely to be the same distance irrespective of the step height in which
case the energy lost will be inversely proportional to the height of the
step (because it will take more steps to climb a given height so the
energy lost will be the loss per step times the number of steps for a
given height).

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Ben C]

On 2007-09-13, Tony Raven > wrote:
> Ben C > wrote in
> :
>
>>
>> I'm not sure about this argument.
>>
>> When you walk up steps you lift your leg up and then push down on the
>> step with it. The fact that your leg has weight means that you can
>> push down a little bit less hard. So you get the potential energy back
>> in spite of not having neutrally balanced cranks.
>
> That would be if you slid your foot onto the step but you don't, you lift
> it above the step and then put it down. Likewise walking up a slope you
> don't slide your foot up the slope but lift it off the surface, move it
> up and then put it down again. Its the putting down bit that wastes
> potential energy that is not wasted on a bike.

I see what you're saying, yes. This could be mitigated by springy shoe
soles (I mean literally springy). You'd only need a slight spring in
them so it wouldn't feel like walking on a trampoline.

All the same, I don't think it's very much energy or that we need
springy shoes. Not that anyone was claiming that it was.

>> I'm not sure about Carl's argument either though. If you walk up steps
>> it doesn't make any difference to the energy expended as far as the
>> basic physics are concerned how high or shallow the steps are.
>>

> It will matter unless the distance you lift your foot above the step
> before putting it down is proportional to the step height. It is more
> likely to be the same distance irrespective of the step height in
> which case the energy lost will be inversely proportional to the
> height of the step (because it will take more steps to climb a given
> height so the energy lost will be the loss per step times the number
> of steps for a given height).

For walking yes. But just to clarify: for cycling, you get it all back
anyway so it doesn't matter that you're lifting your legs a bit higher.
This is what you said in the first place.

[[email protected]]

On Sep 14, 4:15 am, wrote:
> On Sep 12, 1:22 am, " >
> wrote:
>
> > On Sep 10, 3:42 pm, wrote:
>
> > > Our legs have no natural flywheel action and stop spinning as soon as
> > > we stop trying to pedal--it takes constant power to churn those big
> > > chunks of meat and bone up and donwn.
>
> > But obviously very very little power, as anyone who has ever broken a
> > chain or dropped a gear will know. It also takes power to lift a foot
> > up higher than ground level only to put it down again when walking.
> > Which do you think is a greater waste of power, and why? Have you any
> > quantitative estimates of either effect on which to base a comparison?
>
> > James
>
> Dear James,

[...]

> When walking, most people don't lift their feet as high as the step
> _above_ the step that they plant their foot on, unless they're doing a
> very strange goose-step.

So aside from writing down lots of rather arbitrary numbers, do you
actually have any evidence - or can you even produce a meaningful
quantitative estimate - of the supposed inefficiency of the pedalling
motion?

James

[Tom Keats[_5_]]

In article >,
Ryan Cousineau > writes:
> In article >,
> (Tom Keats) wrote:
>
>> In article >,
>> Ryan Cousineau > writes:

>> > Change out your 6-speed for a 7-speed Megarange.
>>
>> Who's got 'em? Everywhere I've gone when needing to
>> update my freewheel, only has those steenkin' 6-spd
>> 14-28s. Sometimes I feel like drop-kickin' 'em into
>> the next universe (or at least, Burnaby.) No doubt
>> they'd eventually return by similar means.
>
> !? Hm. Try phoning Sports Junkies in Port Moody,

I'd rather ride to there. There's this barber shop
on St Johns that does pretty good haircuts anyways.

> and if Bikes on the
> Drive doesn't have it, they're missing their market.
>
> Otherwise, the Internet has lots of them.
>
> But that's weird: the 11-34 7s should be one of the most common
> freewheels around.

The irony is, I'm fixing-up a foundling DiamondBack
Sorrento with one of those on it. I guess its OEM
stuff on the bike, and the luck o' the draw for me,
trying to get replacement components.

IME, the 14-28 6's are much more ubiquitous.
Oh, well -- they're the devil I know, anyway.

Maybe I'm predestined to not have those comfortably
low gears with which one can speed past walkers up
15%+ grades? ;)

Maybe that's like Lonsdale Ave in North Van.
Ooooh, I hate that odius climb. And not just
because of its steepness, but the crass, surrounding
environment. It's like Kingsway on a mountainside.
It's so very anti-inspiring. But there's used to
be a 7-Eleven up there, just across from the KFC,
that's been one of my luckiest Lotto 6/49 sources.
It's been a while since I've been up that way; I
don't know if those establishments still exist.

Yeah, those MegaRanges are around. Synchronicity
just denies me them. Every time I seek & need 'em,
all they've got are 14-28 6's. And Z-Chains :-p


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Artemisia]

Tom Keats wrote:
> But there's used to
> be a 7-Eleven up there, just across from the KFC,
> that's been one of my luckiest Lotto 6/49 sources.

So like a Sagittarian to be lucky at Lotto!

EFR
Ile de France

[CoyoteBoy]

On 6 Sep, 18:09, Artemisia > wrote:
> Peter Clinch wrote:
>
> > I recall one incident when a pal and I were taking our MTBs up a fairly
> > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > While walking, I soon overtook my pal, still spinning happily in 1st...
>
> So isn't it actually more efficient energy use to walk uphill than to
> pedal, even if you do have unimaginably low gears and no topple-over on
> a trike?
>
> I'm thinking perhaps the only advantage of trying to pedal up my hills
> is the inconvenience of trying to stand up out of a recumbent...
>
> EFR
> Ile de France

Was there a conclusion to this thread? Did anyone find evidence that
cycling at walking pace is in fact harder than walking at walking
pace? I only ask as a friend with back problems ends up in severe pain
trying to walk more a distance with his wife, but needs to do the same
quantity of exercise - I was trying to work out if cycling next to his
wife would pose the same energy/heart rate requirements etc and so be
equally beneficial. I know cycling in a straight line is extremely
easy in the granny ring at walking pace but then i dont find walking
hard either so i cant judge, im sure that after 3 miles of granny-ring
riding I'd be knackered lol.

[[email protected]]

On Sep 15, 10:58 pm, CoyoteBoy > wrote:

> Was there a conclusion to this thread? Did anyone find evidence that
> cycling at walking pace is in fact harder than walking at walking
> pace?

Nope, at least not on a road surface under plausible real world
conditions.

>I only ask as a friend with back problems ends up in severe pain
> trying to walk more a distance with his wife, but needs to do the same
> quantity of exercise - I was trying to work out if cycling next to his
> wife would pose the same energy/heart rate requirements etc and so be
> equally beneficial. I know cycling in a straight line is extremely
> easy in the granny ring at walking pace but then i dont find walking
> hard either so i cant judge, im sure that after 3 miles of granny-ring
> riding I'd be knackered lol.

You may have misunderstood the discussion. i don't think anyone ever
suggested that cycling at walking pace *on reasonably level ground*
would require similar effort to walking - the discussion was concerned
with climbing steep hills. Your friend will get almost no exercise
from this approach unless their route is a very steep one, and he may
find it awkward trying to go slowly enough.

When I had a slipped disk a few years ago, I could cycle much more
easily than walk. But I had no reason to travel at 3mph :-)

James

[peter]

On Sep 15, 6:58 am, CoyoteBoy > wrote:

> Was there a conclusion to this thread? Did anyone find evidence that
> cycling at walking pace is in fact harder than walking at walking
> pace? I only ask as a friend with back problems ends up in severe pain
> trying to walk more a distance with his wife, but needs to do the same
> quantity of exercise - I was trying to work out if cycling next to his
> wife would pose the same energy/heart rate requirements etc and so be
> equally beneficial.

They'll only be close to the same effort when going up a very steep
hill. When climbing hills of 30% grade or more, walkers/runners and
cyclists of similar fitness go up at about the same speed - both very
slowly. That may not help your friend much since paved surfaces that
are that steep aren't all that common and neither he nor his wife may
find such a climb enjoyable on a regular basis.

[Rob Morley]

In article om>,
CoyoteBoy
says...

> Was there a conclusion to this thread? Did anyone find evidence that
> cycling at walking pace is in fact harder than walking at walking
> pace? I only ask as a friend with back problems ends up in severe pain
> trying to walk more a distance with his wife, but needs to do the same
> quantity of exercise - I was trying to work out if cycling next to his
> wife would pose the same energy/heart rate requirements etc and so be
> equally beneficial.

What he needs is one of those bikes with hydraulic transmission. :-)

[CoyoteBoy]

On 16 Sep, 02:53, Rob Morley > wrote:
> In article om>,
> CoyoteBoy
> says...
>
> > Was there a conclusion to this thread? Did anyone find evidence that
> > cycling at walking pace is in fact harder than walking at walking
> > pace? I only ask as a friend with back problems ends up in severe pain
> > trying to walk more a distance with his wife, but needs to do the same
> > quantity of exercise - I was trying to work out if cycling next to his
> > wife would pose the same energy/heart rate requirements etc and so be
> > equally beneficial.
>
> What he needs is one of those bikes with hydraulic transmission. :-)

The other option was a turbo trainer but it would have been nicer to
have the exercise outside with his wife :)

[CoyoteBoy]

On 16 Sep, 00:04, " >
wrote:
> On Sep 15, 10:58 pm, CoyoteBoy > wrote:
>
> > Was there a conclusion to this thread? Did anyone find evidence that
> > cycling at walking pace is in fact harder than walking at walking
> > pace?
>
> Nope, at least not on a road surface under plausible real world
> conditions.
>
> >I only ask as a friend with back problems ends up in severe pain
> > trying to walk more a distance with his wife, but needs to do the same
> > quantity of exercise - I was trying to work out if cycling next to his
> > wife would pose the same energy/heart rate requirements etc and so be
> > equally beneficial. I know cycling in a straight line is extremely
> > easy in the granny ring at walking pace but then i dont find walking
> > hard either so i cant judge, im sure that after 3 miles of granny-ring
> > riding I'd be knackered lol.
>
> You may have misunderstood the discussion. i don't think anyone ever
> suggested that cycling at walking pace *on reasonably level ground*
> would require similar effort to walking - the discussion was concerned
> with climbing steep hills. Your friend will get almost no exercise
> from this approach unless their route is a very steep one, and he may
> find it awkward trying to go slowly enough.
>
> When I had a slipped disk a few years ago, I could cycle much more
> easily than walk. But I had no reason to travel at 3mph :-)
>
> James

I didnt really misunderstand the OP, more I was trying to drag more
out of it than originally was asked lol. The route is off-road and
fairly hilly but not very hilly. The friend has 2 compressed and
slipped lower discs and 3 vertebrae fused in his neck and has put up
with them as-is for longer than I care to think about, despite being
in agony silently. The problem is having recently had a heart problem
he has been told he needs to exercise (he isnt fat, just not fit) and
walking is leaving him in a lot of pain, so he is just avoiding
exercise all together - not ideal. Anything would be better than
nothing. I was going to loan my bike out as and when he needs it
(right size, give or take moving the saddle a smidge). I suppose his
wife could get her bike out too in order to have them both doing a
half-decent pace, but this is going to be a mammoth task to get them
both interested lol!

[CoyoteBoy]

On 16 Sep, 00:40, peter > wrote:
> On Sep 15, 6:58 am, CoyoteBoy > wrote:
>
> > Was there a conclusion to this thread? Did anyone find evidence that
> > cycling at walking pace is in fact harder than walking at walking
> > pace? I only ask as a friend with back problems ends up in severe pain
> > trying to walk more a distance with his wife, but needs to do the same
> > quantity of exercise - I was trying to work out if cycling next to his
> > wife would pose the same energy/heart rate requirements etc and so be
> > equally beneficial.
>
> They'll only be close to the same effort when going up a very steep
> hill. When climbing hills of 30% grade or more, walkers/runners and
> cyclists of similar fitness go up at about the same speed - both very
> slowly. That may not help your friend much since paved surfaces that
> are that steep aren't all that common and neither he nor his wife may
> find such a climb enjoyable on a regular basis.

It would be off-road riding through the local fields, but not very
steep. Probably 15 degrees or so for a short period but generally
fairly flat after that. I'll see if i can get them both on bikes :)

[[email protected]]

On Sep 16, 8:24 pm, CoyoteBoy > wrote:
>
> I didnt really misunderstand the OP, more I was trying to drag more
> out of it than originally was asked lol. The route is off-road and
> fairly hilly but not very hilly.

Well, soft ground certainly handicaps a cyclist more than a walker, so
maybe it's not such a completely unreasonable idea after all (but if
it's soft enough to matter, it will probably be very slippery and not
much fun for cycling).

When (very rarely rarely) out jogging with a slower companion, I
sometimes do a few extra detours to top up my exercise level.

James

[Tom Keats]

In article >,
Artemisia > writes:
> Tom Keats wrote:
>> But there's used to
>> be a 7-Eleven up there, just across from the KFC,
>> that's been one of my luckiest Lotto 6/49 sources.
>
> So like a Sagittarian to be lucky at Lotto!

I don't play it that often, and I've never "won"
more than $12. My luck manifests more in my being
able to occasionally royally screw-up, and yet have
people nevertheless still liking me.

I refuse to play poker. Poker isn't a sporting game,
it's a war -- the objective is to deprive your opponent
of what he has. Poker is too mean & cruel for me.

Sometimes I find $20 bills lying around. Canadian $20
bills are almost the same colour as grass. A Canadian
$20 bill lying on grass is easily overlooked by the
untrained eye. In the past I've lost $20 bills.
Sometimes I give my spare $20 bills to people sleeping
on bus stop benches; people who obviously travelled to/
ended-up here from Alberta or Ontario by whatever means,
because they were predilected to do so, and they're
compelled to follow their Lines of Destiny.

I guess it's more quismut than luck. What comes around,
goes around.

I figure society is a flowing current. Sometimes our belongings
get carried away by the current, and sometimes stuff
floats by in reaching distance. And sometimes stuff
floats by, just out of reach. Like those MegaRange
freewheels. Oh, well. At least the 14-28 HyperGlides
are easy to set up the shifting for, and I can get by
with 'em.


cheers,
Tom

--
Nothing is safe from me.
I'm really at:
tkeats curlicue vcn dot bc dot ca

[Chris Malcolm]

In uk.rec.cycling CoyoteBoy > wrote:
> On 6 Sep, 18:09, Artemisia > wrote:
>> Peter Clinch wrote:
>>
>> > I recall one incident when a pal and I were taking our MTBs up a fairly
>> > steep grassy field. I got bored at walking pace, and decided I'd walk.
>> > While walking, I soon overtook my pal, still spinning happily in 1st...
>>
>> So isn't it actually more efficient energy use to walk uphill than to
>> pedal, even if you do have unimaginably low gears and no topple-over on
>> a trike?
>>
>> I'm thinking perhaps the only advantage of trying to pedal up my hills
>> is the inconvenience of trying to stand up out of a recumbent...
>>
>> EFR
>> Ile de France

> Was there a conclusion to this thread? Did anyone find evidence that
> cycling at walking pace is in fact harder than walking at walking
> pace? I only ask as a friend with back problems ends up in severe pain
> trying to walk more a distance with his wife, but needs to do the same
> quantity of exercise - I was trying to work out if cycling next to his
> wife would pose the same energy/heart rate requirements etc and so be
> equally beneficial. I know cycling in a straight line is extremely
> easy in the granny ring at walking pace but then i dont find walking
> hard either so i cant judge, im sure that after 3 miles of granny-ring
> riding I'd be knackered lol.

I often have to cycle up long smooth steep hills while carrying a
heavy briefcase on which I'm uncomfortably over-exerted if I exceed
4-5mph for long. I also sometimes choose to walk the same route
carrying the same weight just for a change, and I suspect I can't
comfortably exceed 3mph on foot. It's certainly the case that when I'm
on foot I'm often overtaken by younger quicker walkers, whereas on the
bike I slowly but surely pass even the fastest walkers.

And of course when I'm on the bike I'm lifting its weight up the hill too!

One of those megarange granny gears greatly improved my comfort, and
slightly improved my speed, on those hills, because without it I
either struggled more slowly with an inefficiently slow cadence,
e.g. standing on the pedals, or I got off and pushed.

Incidentally, I can push the loaded bicycle up a hill a lot faster
then I could carry it, and can push it up hills carrying loads I'd
find it almost impossible to carry on my shoulders up hill. There's
clearly a saving in having the weight on wheels, regardless of how the
wheels are turned.

So my guess, based on these experiences, is that cycling up hill at a
walking speed in an appropriate gear is a bit easier than walking,
because the extra bicycle weight is more than swallowed by the wheel
effect, and the more weight you carry the bigger the
difference. Incidentally I weigh 130lbs.

--
Chris Malcolm DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]

[Roger Merriman]

> wrote:

> On Sep 16, 8:24 pm, CoyoteBoy > wrote:
> >
> > I didnt really misunderstand the OP, more I was trying to drag more
> > out of it than originally was asked lol. The route is off-road and
> > fairly hilly but not very hilly.
>
> Well, soft ground certainly handicaps a cyclist more than a walker, so
> maybe it's not such a completely unreasonable idea after all (but if
> it's soft enough to matter, it will probably be very slippery and not
> much fun for cycling).
>
if he has access to a mountain bike, with half decent tires that should
be okay, i'm assumeing parklands and such?

> When (very rarely rarely) out jogging with a slower companion, I
> sometimes do a few extra detours to top up my exercise level.
>
> James

roger

--
www.rogermerriman.com

[Roger Merriman]

CoyoteBoy > wrote:

> On 6 Sep, 18:09, Artemisia > wrote:
> > Peter Clinch wrote:
> >
> > > I recall one incident when a pal and I were taking our MTBs up a fairly
> > > steep grassy field. I got bored at walking pace, and decided I'd walk.
> > > While walking, I soon overtook my pal, still spinning happily in 1st...
> >
> > So isn't it actually more efficient energy use to walk uphill than to
> > pedal, even if you do have unimaginably low gears and no topple-over on
> > a trike?
> >
> > I'm thinking perhaps the only advantage of trying to pedal up my hills
> > is the inconvenience of trying to stand up out of a recumbent...
> >
> > EFR
> > Ile de France
>
> Was there a conclusion to this thread? Did anyone find evidence that
> cycling at walking pace is in fact harder than walking at walking
> pace? I only ask as a friend with back problems ends up in severe pain
> trying to walk more a distance with his wife, but needs to do the same
> quantity of exercise - I was trying to work out if cycling next to his
> wife would pose the same energy/heart rate requirements etc and so be
> equally beneficial. I know cycling in a straight line is extremely
> easy in the granny ring at walking pace but then i dont find walking
> hard either so i cant judge, im sure that after 3 miles of granny-ring
> riding I'd be knackered lol.

the other option is other forms of exersize that he could do, such as
swiming?

roger
--
www.rogermerriman.com

[Rob Morley]

In article >, Roger
Merriman
says...

> the other option is other forms of exersize that he could do, such as
> swiming?
>
Fused neck = face underwater? :-)

[Rob Morley]

In article >, Chris Malcolm
says...
> Incidentally I weigh 130lbs.
>
Get thee to ye pie shoppe forthwith. ;-)

[Roger Merriman]

Rob Morley > wrote:

> In article >, Roger
> Merriman
> says...
>
> > the other option is other forms of exersize that he could do, such as
> > swiming?
> >
> Fused neck = face underwater? :-)

ahh got to admit i did skim, i blame not enought sleep and no coffee one
of which shall be solved shortly.

roger
--
www.rogermerriman.com

[Tony Raven[_2_]]

In article >,
says...
> In article >, Roger
> Merriman
> says...
>
> > the other option is other forms of exersize that he could do, such as
> > swiming?
> >
> Fused neck = face underwater? :-)
>

Backstroke?

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Peter Clinch]

Tony Raven wrote:
> In article >,
> says...
>> In article >, Roger
>> Merriman
>> says...
>>
>>> the other option is other forms of exersize that he could do, such as
>>> swiming?
>>>
>> Fused neck = face underwater? :-)

> Backstroke?

I swim a fair bit, and do the backstroke by preference ('cause I don't
need any talent to get the breathing right!), and while it was my first
thought here one does need to be aware that the swimmer will need to be
supporting their own head to some degree. Depending on the exact nature
of "fused neck" that /might/ be a problem and will need thought, but if
keeping any strain off isn't going to be an issue I'd think it's quite
possibly a goer.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Tony Raven[_2_]]

In article >,
says...
>
> I swim a fair bit, and do the backstroke by preference ('cause I don't
> need any talent to get the breathing right!), and while it was my first
> thought here one does need to be aware that the swimmer will need to be
> supporting their own head to some degree. Depending on the exact nature
> of "fused neck" that /might/ be a problem and will need thought, but if
> keeping any strain off isn't going to be an issue I'd think it's quite
> possibly a goer.
>
> Pete.
>

If he can't support his head swimming backstroke then I doubt he could
support it either on all but the most upright posture bicycles.

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

[Peter Clinch]

Tony Raven wrote:

> If he can't support his head swimming backstroke then I doubt he could
> support it either on all but the most upright posture bicycles.

probably, which is why I raised it. However, with a different position
and circumstances (more disadvantageous with respect to gravity being at
right angles, but OTOH some support from buoyancy) probably a
suck-it-and-see.

on a bike, even a bolt-upright one, you've got additional problems like
looking behind you to think about. Actually, could be a problem with
backstroke too, but pootling into a pool-side a bit less traumatic than
saying hello to a truck doing 30.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Roger Merriman]

Peter Clinch > wrote:

> Tony Raven wrote:
>
> > If he can't support his head swimming backstroke then I doubt he could
> > support it either on all but the most upright posture bicycles.
>
> probably, which is why I raised it. However, with a different position
> and circumstances (more disadvantageous with respect to gravity being at
> right angles, but OTOH some support from buoyancy) probably a
> suck-it-and-see.
>
> on a bike, even a bolt-upright one, you've got additional problems like
> looking behind you to think about. Actually, could be a problem with
> backstroke too, but pootling into a pool-side a bit less traumatic than
> saying hello to a truck doing 30.
>
> Pete.

if he's at that point some of the recumbands i see around bushy park
would be better.

and he would need mirrors etc to go on road safely, though for slow
pottle in park not such a issue. just keeping pace with walking wife?

roger
--
www.rogermerriman.com

[Coyoteboy]

Roger Merriman wrote:
>>
> if he has access to a mountain bike, with half decent tires that should
> be okay, i'm assumeing parklands and such?
>
> roger
>

Well, bridle ways through fields. He would have access to full sus bike
and nice knobblies :)

[Roger Merriman]

Coyoteboy > wrote:

> Roger Merriman wrote:
> >>
> > if he has access to a mountain bike, with half decent tires that should
> > be okay, i'm assumeing parklands and such?
> >
> > roger
> >
>
> Well, bridle ways through fields. He would have access to full sus bike
> and nice knobblies :)

sounds like he has good friend then!

roger
--
www.rogermerriman.com