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  #321  
Old October 21st 14, 01:46 AM posted to rec.bicycles.tech
James[_8_]
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Posts: 6,153
Default Gearing for steep hills

On 21/10/14 10:35, Joe Riel wrote:
Joe Riel writes:

James writes:

On 21/10/14 09:06, Joe Riel wrote:

In spring, while doing hill repeats with a Garmin, I compared my time up
the same climb multiple times. It's a fairly short, about a half mile,
and climbs a couple hundred feet. Invariably I find that I'm fastest up
in a rather big gear. I'm not trying to go fast, but rather maintain a
comfortably hard tempo. The gear that is the fastest is bigger than one
I'd normally use to climb the hill. Seems odd to me.


I thought we were talking about maintaining a high cadence going up
hill, not fastest speed up a short hill.


The point I was making is that the high cadence isn't necessarily the
fastest. As mentioned, I wasn't trying to go fast up the hill; I didn't
monitor my speed while climibing, just climbed at a comfortably hard
rate, essentially matching the effort I put out on longer climbs.
I was surprised that the I was faster in a bigger gear.

I suspect that with the higher cadence I get bored (for want of a better
term) and tend to slow down. With the bigger gear I have to work to
stay on top of it and so maintain a more even power output. Put
differently, with a high cadence it is more comfortable to slow down,
with a lower cadence, not so much.


As I understand it, a high cadence isn't necesarily the most efficient
or most effective. It may require a higher heart rate for the same
power output. For well trained athletes that can be advantageous if
doing saves muscle energy that can be employed later for some strategic
advantage.


In races I try to keep my cadence above 90. As it drops below 90 the
effort seems to start to increase dramatically. The legs get that "I'm
starting to labour here" feeling.

I actually watched my cadence during races, and as it drops toward 90
going up some hills, I selected the next lower gear, which keeps my
cadence between 90 and 100. This give the fastest and least tiring
approach.

Sure I could go faster in a bigger gear, and just keep thumping along.
It would then take longer to recover afterwards, and overall I'd be more
tired at the business end of the race.

Saving your body for an almighty effort at the end of a race is often
what gets you across the line in a better position.

--
JS
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  #322  
Old October 21st 14, 02:28 AM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default Dynohub drag

On Monday, October 20, 2014 3:25:07 PM UTC-7, James wrote:
On 21/10/14 01:31, jbeattie wrote:





What I'm getting at is that with a dyno light, you have an inherently


hobbled light.




Especially now with LEDs, I disagree.



If it is StVZO compliant, it is purposefully hobbled


in terms of its output.




Not at all. It's only "hobbled" in terms of how much light is allowed

to reach other road users eyes. IIRC, there's no limit on how much

light hits the road.



Mine for example, produces 80lux at 10m as the horizontal straight ahead

intensity.


What light are you using again? I'm not wanting to wire multiple headlights that flicker on climbs or fire-up after I'm off the stop. I've already got 3 LEDs that fire up at different speeds.

Whatever you may think of battery lights, I could strap my battery light back on the bike and ride for 11 hours with a reasonably well shaped 300 lumen beam -- not StVZO but not a Chinese flashlight either. No fuss, no muss -- no flickering, outages at stops. None of that. Well made US lights are not by definition round beam retina burners -- unless your running a trail light at maximum output. I don't know what your mates are running, but my battery lights have garnered no complaints from motorists or other cyclist. There was a bum on a park bench who complained about my flasher, but I was trying to chase him off anyway. Flashers are a different problem.

-- Jay Beattie.
  #323  
Old October 21st 14, 02:43 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default Dynohub drag

On 10/20/2014 8:29 AM, AMuzi wrote:
On 10/19/2014 9:11 PM, Sir Ridesalot wrote:

I remeber seeing ads by Soubitez (sp?) that had a standlight even
though that front mounted dynamo powered an incandescent bulb. I
distinctly remember the two pictures in the ad with one showing a
stopped bicycle at an intersection with no front light showing and
another image showing the standlight being visible to motorists.
So at least one well respected bicycle dynamo lighting manufacturer
back in the 1980s thought tthat a dynamo standlight was a good thing.


Worked as advertised but sold miserably. Lots of 'hey that's cool' but
precious few sales.


Do you know how the standlight was powered?

--
- Frank Krygowski
  #324  
Old October 21st 14, 03:07 AM posted to rec.bicycles.tech
James[_8_]
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Posts: 6,153
Default Dynohub drag

On 21/10/14 12:28, jbeattie wrote:
On Monday, October 20, 2014 3:25:07 PM UTC-7, James wrote:
On 21/10/14 01:31, jbeattie wrote:





What I'm getting at is that with a dyno light, you have an
inherently


hobbled light.




Especially now with LEDs, I disagree.



If it is StVZO compliant, it is purposefully hobbled


in terms of its output.




Not at all. It's only "hobbled" in terms of how much light is
allowed

to reach other road users eyes. IIRC, there's no limit on how
much

light hits the road.



Mine for example, produces 80lux at 10m as the horizontal straight
ahead

intensity.


What light are you using again?


http://www.xxcycle.com/busch-and-mul...ndi-04,,en.php

I'm not wanting to wire multiple
headlights that flicker on climbs or fire-up after I'm off the stop.
I've already got 3 LEDs that fire up at different speeds.


I have one head light and one tail light.

For twisting descents at night, a flood light would be nice, but it's
not difficult to slow a bit so the bike doesn't lean as much. That is
about the only down side for me. I would add a second headlight for
high beam mode, wired in series and with a bypass switch, if I did that
sort of riding frequently.

Whatever you may think of battery lights, I could strap my battery
light back on the bike and ride for 11 hours with a reasonably well
shaped 300 lumen beam -- not StVZO but not a Chinese flashlight
either.


That's nice. I fill a water bottle or two, get on my bike and ride.

The only battery I have to think about is in my Garmin - which would be
a real nuisance if I didn't want to download the data anyway.

Do you have a powered hub next to your bike and an octopus of cables
ready to plug everything in at the end of a ride?

--
JS
  #325  
Old October 21st 14, 03:16 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default Dynohub drag

On 10/20/2014 10:31 AM, jbeattie wrote:


What I'm getting at is that with a dyno light, you have an inherently hobbled light.

If it is StVZO compliant, it is purposefully hobbled in terms of its
output.

Not so. AFAIK, StVZO does not limit the number of lumens (i.e.
"output"). It imposes minimums for road illumination, not maximums.
It "hobbles" only in the same way that car headlights are "hobbled," to
not harm others. And in the process, it uses the lamp's output very
efficiently. That's a good thing.

Even if it is not StVZO compliant, it is hobbled by its limited input

voltage.

Also wrong. Sorry, Jay. The limitation on a typical dynamo is output
current, since they naturally (by design) put out a little over half an
amp, pretty much constant current. Voltage rises to match the load. If
there were enough benefit to running a standard dynamo at higher
voltage, it would be done by lamp manufacturers. Typical high output
LEDs need less than four volts anyway.

So, you have to agonize over reflectors, beam shapes, etc. because you have

to squeeze as much performance as possible out of a hobbled light.

Well, in the same sense that people who buy tires have to agonize over
longevity vs. rolling resistance vs. traction, etc. All equipment
decisions are compromises.

And the only reason most buyers of battery lights don't agonize over
reflectors, beam shapes, etc. is because their thought process stops
after "This one's on sale, and gee, it looks bright when I shine it in
my face!" Anyone who seriously shops for a light - battery or dynamo -
should be looking at the beam shots posted on the web.

I'll remind you that a survey of Paris-Brest-Paris riders a few years
ago found that dynamo light users were much more satisfied with their
lights than were battery light users. That doesn't match the idea of
"hobbled." And that was before dynamos did LEDs. If anything that
preference has probably gotten stronger.

Again, I'm sorry you got something that didn't match you unusual needs.
But your complaints apply to very few people; most of us don't go
walking our bikes up super-dark steep trails in the rain! If you'd
discussed that need here beforehand, you might have gotten some useful
advice.

As it was, the advice I gave was to arrange to try one out. I think it
would have been a useful move. In fact, I still think it would be a
useful move.

--
- Frank Krygowski
  #326  
Old October 21st 14, 04:23 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default Gearing for steep hills

On 10/20/2014 6:10 PM, Sir Ridesalot wrote:


That or the more common 42 - 24 was a large reason why many

people tried bicycling but gave it up. That low gear wasn't
low enough for many who were just getting into bicycling nor
was it low enough for many who wanted a lightweieght bicycle
for general running around, commuting or to run errands with.
I wonder if during tthe 1970s and 1980s bike nooms if a gear
of even 34 - 24 or 34 - 30 would have kept more would be bicyclists
in the sport? That in turn would h ave made for safer riding due
to far more bicyclists on the road.

I've read many times that hills are one of the big items that dissuade
people from cycling. In general, flat cities tend to have more cyclists
than hilly ones (although of course we'll hear about exceptions).

And I remember letting one friend of mine try my bike with its (then)
newly installed triple crank. His remark: "Wow! It doesn't matter if
there's a hill or not!" And he soon bought a bike with a triple.

But as with most technical aspects of bicycling, people don't understand
what's important, and few salesmen explain it. 12 speeds were always
portrayed as better than 10, 14 better than 12, etc., but few people
bothered to ask about how low the gears were. In fact, a lot of the
gear count was wasted (for non-competitors) on gears above 100 gear
inches. Much better to give them lower gears, even if seldom used.


--
- Frank Krygowski
  #327  
Old October 21st 14, 04:55 AM posted to rec.bicycles.tech
Sir Ridesalot
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Posts: 5,270
Default Gearing for steep hills

On Monday, October 20, 2014 11:23:13 PM UTC-4, Frank Krygowski wrote:
On 10/20/2014 6:10 PM, Sir Ridesalot wrote:





That or the more common 42 - 24 was a large reason why many


people tried bicycling but gave it up. That low gear wasn't

low enough for many who were just getting into bicycling nor

was it low enough for many who wanted a lightweieght bicycle

for general running around, commuting or to run errands with.

I wonder if during tthe 1970s and 1980s bike nooms if a gear

of even 34 - 24 or 34 - 30 would have kept more would be bicyclists

in the sport? That in turn would h ave made for safer riding due

to far more bicyclists on the road.



I've read many times that hills are one of the big items that dissuade

people from cycling. In general, flat cities tend to have more cyclists

than hilly ones (although of course we'll hear about exceptions).



And I remember letting one friend of mine try my bike with its (then)

newly installed triple crank. His remark: "Wow! It doesn't matter if

there's a hill or not!" And he soon bought a bike with a triple.



But as with most technical aspects of bicycling, people don't understand

what's important, and few salesmen explain it. 12 speeds were always

portrayed as better than 10, 14 better than 12, etc., but few people

bothered to ask about how low the gears were. In fact, a lot of the

gear count was wasted (for non-competitors) on gears above 100 gear

inches. Much better to give them lower gears, even if seldom used.





--

- Frank Krygowski


Yes, the high gear of just over 100 gear inches with the standard 52 x 14 combination on jmany road bikes was too high for a lot of people. Now theyre selling bicycles with a 53 chain ring and 12 or 11 teeth cogs as standard. In my opinion it'd be a lot better to have lower gears on the standard bikes for the general public and the higher gears for the more elite riders. It seems to me that over gearing many bicycles results in bicycles tthat a lot of people can never hope to use the high gears of - ever. That turns people off bicycling.

Far too many times i have people ask me where i'm going to ride. When i tell them and they ask if there are any hills tthey're usually put off because their bikes just don't have the low gears they need.

Changing from a 52 - 42 double to a 30 - 40 -50 triple is very expensive for a lot of people as it means getting a new crankset, bottom bracket (if it's a sealed unit) chain and many times a new rear mech. If they're really unlucky, they need a new fron mech too.I really believe that a lot of people are sold bicycles that are totally unsuited to their actual needs. Cyclo-cross bicycles with wided clearances and barzeons for racks etcetera are very popular here in town due to those bicycles being so versatile.

Cheers
  #328  
Old October 21st 14, 04:57 AM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default Dynohub drag

On Monday, October 20, 2014 7:16:42 PM UTC-7, Frank Krygowski wrote:
On 10/20/2014 10:31 AM, jbeattie wrote:





What I'm getting at is that with a dyno light, you have an inherently hobbled light.


If it is StVZO compliant, it is purposefully hobbled in terms of its

output.



Not so. AFAIK, StVZO does not limit the number of lumens (i.e.

"output"). It imposes minimums for road illumination, not maximums.

It "hobbles" only in the same way that car headlights are "hobbled," to

not harm others. And in the process, it uses the lamp's output very

efficiently. That's a good thing.



Even if it is not StVZO compliant, it is hobbled by its limited input


voltage.



Also wrong. Sorry, Jay. The limitation on a typical dynamo is output

current, since they naturally (by design) put out a little over half an

amp, pretty much constant current. Voltage rises to match the load. If

there were enough benefit to running a standard dynamo at higher

voltage, it would be done by lamp manufacturers. Typical high output

LEDs need less than four volts anyway.


Yes, if you want to wire up lights in series, you can do that. But, I believe StVZO limits a single light to 2.4 watts -- just because. And if you wire a bunch of lights in series, be content riding in the dark when your speed drops. But, hey, you don't need light when your riding slowly.






So, you have to agonize over reflectors, beam shapes, etc. because you have


to squeeze as much performance as possible out of a hobbled light.



Well, in the same sense that people who buy tires have to agonize over

longevity vs. rolling resistance vs. traction, etc. All equipment

decisions are compromises.


Right, and if a tire has no wet grip, it is a bad tire. It shouldn't be on the market. Its an UmmaGumma, yet with dyno lights, they can suck, and it's O.K. because they're special! And quirky!




And the only reason most buyers of battery lights don't agonize over

reflectors, beam shapes, etc. is because their thought process stops

after "This one's on sale, and gee, it looks bright when I shine it in

my face!" Anyone who seriously shops for a light - battery or dynamo -

should be looking at the beam shots posted on the web.



Have you bothered looking at decent battery lights? And by the way, I looked at on-line beam patterns -- many were disturbingly pitiful, but the SuperNova looked promising.

I'll remind you that a survey of Paris-Brest-Paris riders a few years

ago found that dynamo light users were much more satisfied with their

lights than were battery light users. That doesn't match the idea of

"hobbled." And that was before dynamos did LEDs. If anything that

preference has probably gotten stronger.


I'll remind you that my commute is not 600 miles. I'll remind you that most 24 hour mountain bike racers use battery lights. I'll remind you that virtually every cyclist I see every night (which is a lot of cyclists) use little 120 gram bar lights that produce plenty of light -- more than most dynos and with zero complexity.





Again, I'm sorry you got something that didn't match you unusual needs.

But your complaints apply to very few people; most of us don't go

walking our bikes up super-dark steep trails in the rain! If you'd

discussed that need here beforehand, you might have gotten some useful

advice.



As it was, the advice I gave was to arrange to try one out. I think it

would have been a useful move. In fact, I still think it would be a

useful move.



You're f****** nuts. NO store would give me a light to try, and only one had a display with a wheel and dyno where you could switch between the lights. Otherwise, it was little lights on peg-boards or in cabinets with shiny new wire-ends that the stores intended to keep shiny. What am I supposed to do? Go door to door asking for a dyno light?

And about my unusual needs -- almost any of the 500 lumen lights at the bike shop would suit my needs. But with dynos, I have to have an advanced degree to pick a light? Crap, with my battery light, I hit a fast downhill, and I just up the output. It's not like I have to stop and select a different light or add a light.

-- Jay Beattie.



  #329  
Old October 21st 14, 05:27 AM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default Gearing for steep hills

On Monday, October 20, 2014 5:46:09 PM UTC-7, James wrote:
On 21/10/14 10:35, Joe Riel wrote:

Joe Riel writes:




James writes:




On 21/10/14 09:06, Joe Riel wrote:




In spring, while doing hill repeats with a Garmin, I compared my time up


the same climb multiple times. It's a fairly short, about a half mile,


and climbs a couple hundred feet. Invariably I find that I'm fastest up


in a rather big gear. I'm not trying to go fast, but rather maintain a


comfortably hard tempo. The gear that is the fastest is bigger than one


I'd normally use to climb the hill. Seems odd to me.






I thought we were talking about maintaining a high cadence going up


hill, not fastest speed up a short hill.




The point I was making is that the high cadence isn't necessarily the


fastest. As mentioned, I wasn't trying to go fast up the hill; I didn't


monitor my speed while climibing, just climbed at a comfortably hard


rate, essentially matching the effort I put out on longer climbs.


I was surprised that the I was faster in a bigger gear.




I suspect that with the higher cadence I get bored (for want of a better


term) and tend to slow down. With the bigger gear I have to work to


stay on top of it and so maintain a more even power output. Put


differently, with a high cadence it is more comfortable to slow down,


with a lower cadence, not so much.




As I understand it, a high cadence isn't necesarily the most efficient


or most effective. It may require a higher heart rate for the same


power output. For well trained athletes that can be advantageous if


doing saves muscle energy that can be employed later for some strategic


advantage.






In races I try to keep my cadence above 90. As it drops below 90 the

effort seems to start to increase dramatically. The legs get that "I'm

starting to labour here" feeling.



I actually watched my cadence during races, and as it drops toward 90

going up some hills, I selected the next lower gear, which keeps my

cadence between 90 and 100. This give the fastest and least tiring

approach.



Sure I could go faster in a bigger gear, and just keep thumping along.

It would then take longer to recover afterwards, and overall I'd be more

tired at the business end of the race.



Saving your body for an almighty effort at the end of a race is often

what gets you across the line in a better position.


I used to ride with a guy who became world class (8th '95 world TT, USPro champ, dozens of domestic pro wins), and his cadence was probably 60-70 rpm tops on steep climbs, but that was back in the 42/21 days. Mine was even slower. It wasn't until Lance came along that everyone started spinning up hill -- probably for the best. I spin now just to survive and could never return to my Regina Oro 5sp 13-21 (or 19) of yore. Plenty of people could, though. The world is full of genetic freaks who appear to defy gravity. I avoid riding with them.

-- Jay Beattie.




  #330  
Old October 21st 14, 06:07 AM posted to rec.bicycles.tech
SMS
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Posts: 9,477
Default Dynohub drag

On 10/20/2014 8:57 PM, jbeattie wrote:

Yes, if you want to wire up lights in series, you can do that. But, I believe StVZO limits a single light to 2.4 watts -- just because. And if you wire a bunch of lights in series, be content riding in the dark when your speed drops. But, hey, you don't need light when your riding slowly.


you're

I'll remind you that my commute is not 600 miles. I'll remind you that most 24 hour mountain bike racers use battery lights. I'll remind you that virtually every cyclist I see every night (which is a lot of cyclists) use little 120 gram bar lights that produce plenty of light -- more than most dynos and with zero complexity.


I saw a dyno user a few weeks ago. Two dynos on the same Caltrain,
train, me and him. It must have set some sort of a record.

 




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