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Steel frames and le Tour



 
 
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  #521  
Old July 18th 08, 10:40 PM posted to rec.bicycles.tech,rec.bicycles.racing
[email protected][_2_]
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Posts: 1,594
Default Steel frames and le Tour

On Jul 17, 4:10 pm, "Tom Kunich" cyclintom@yahoo. com wrote:
"Tuschinski" wrote in message

...



And indeed when you look at the actual numbers of
failures you find that a correctly built steel frame, even superlight
ones,
very seldom fail and when they do it is pretty plainly a workmanship or
material error.


Oh come on Tom, that's blatantly false. Back in the days, when we all
raced Reynolds/Columbus we broke frames. Some of it by crashing, some
by bad handling, some by bad manufacturers.


And yes, we also broke Alu frames. And now we break CF frames
*shrug*.


Such is life ^^


I don't follow you here. Well built steel frames seldom fail. Well built AL
frames (the super light ones) fail whether you take good care of them or
not. I have personally observed quite a few carbon fiber failures and these
bikes are EXPENSIVE.

And the total savings a My Time VX costs almost 4 times more than my
Basso Loto and they ride almost identically and weigh within a lb of each
other.


I used to have a Basso Ascot. It was my favorite bike ever. It died in
a collision with a car and I didn't do too well either. It was a great
frame, though. I think that it was the geometry that made the bike
feel really nice. I don't know if your Lotto has the same geometry as
my Ascot, but if it does, I know why you like it. I am sure that I
will also be able to get a great ride with frames of different
materials that have the same geometry as my Ascot. A lot of the times,
a cyclist may like a bike more because the geometry makes it feel
faster.

I believe , like Carl, that the feeling is just that and your speed
does not necessarily increase or decrease that much. However, it is
great to ride on a bike that has "that" feeling.

Andres
Ads
  #522  
Old July 18th 08, 11:35 PM posted to rec.bicycles.tech,rec.bicycles.racing
[email protected]
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Posts: 7,934
Default Steel frames and le Tour

On Thu, 17 Jul 2008 23:08:40 -0600, Bret Wade
wrote:

wrote:
On Thu, 17 Jul 2008 14:13:43 -0600, Bret Wade
wrote:

wrote:

The original question was whether a rider can _feel_ such tiny
changes--that same old laughable "noticeably robust forward thrust."
I wouldn't put it in those words but I have felt that sensation when
switching from a 4 lb Ti frame to a 2.5 lb Al frame. It felt faster from
the first pedal stroke. It was a team bike that I was somewhat skeptical
of riding, so it wasn't just wishful thinking. Others on the team had
similar experiences. I understand physics well enough to know that the
sensation was misleading.

Bret


Dear Bret,

Forgive a long-winded answer, but you're so refreshingly reasonable
that I want to avoid any offense.

What interests me is the idea that a 1.5 lb lighter frame "felt faster
from the first pedal stroke"--possibly a generalization or even
hyperbole, but it's what we have to work with.

I don't know the actual weights, but it was a whole team, so a 150
pound rider and a 16.5 pound bike would probably be in the ballpark.

That theoretical 166.5 pound bike and rider would drop to 165 pounds,
about 0.9%.

The bike itself would have dropped from 16.5 to 15.0 pounds, about
10%.

The bike might twitch from side to side or heave forward 10% easier.

But I gather that we agree that the speed and acceleration
improvements are going to be so small that a calculator is necessary
to see them.

In fact, they don't show up on my first effort:
http://bikecalculator.com/veloUS.html

I tried 400 watts, a 150 pound rider, 15 and 16.5 pound bikes,
tubulars, and drops.

Because the calculator has only 2-decimal precision, both bikes went
the same speed--27.85 mph.

(A quick look at the time for 20 miles reassured me that the
calculator is still grinding out infinitesimal details--43.08 minutes
versus 43.09 minutes, a 0.01 minute lead, 0.6 seconds.)

Let's send the bikes up the Alp d'Huez, which I have handy at 8.1% and
13.8 km (8.56 miles):
http://en.wikipedia.org/wiki/Alpe_d'Huez

The steep grade teases out a speed difference, but it's still nothing
that a rider could detect.

I get 41.03 minutes versus 41.33, a 0.3 minute or 18 second lead after
almost 2500 seconds. That's ~1% faster.

The speeds are 12.52 mph versus 12.43 mph.

Raise the power to 500 watts, and the time and difference shrink to
34.04 versus 34.27, a little under 14 seconds, at 15.09 versus 14.99
mph.

In other words, it takes the Alp d'Huez and a light, world-class rider
to produce a tenth of a mile per hour and 14-second difference with a
1.5 pound lighter bike.

So I'm glad that you understand the physics well enough to know that
the impression was probably misleading. In unblinded testing, it's
hard to tell which way our misperceptions will go. Just paying
attention (because we're testing) distorts what we think we feel. Evil
psychologists love to demonstrate how students will mis-measure the
same lumber with the same measuring tapes, according to whether
they've been told that it's important for the boards not to be too
long, for them not to be too short, or that the measurement accuracy
does (or doesn't) really matter.

Cheers,

Carl Fogel


Dear Carl,

No need to apologize, I understand that bad habits can be hard to break.
The hardest thing I've done in my life is break a pack a day Marlboro habit.

Anyway, I'll just point out that your very detailed analysis involves
steady state aerobic climbing whereas most "Wow, this bike is fast!"
moments will come during anaerobic accelerations. Not that I think the
result would be much different. A small change in total mass won't
affect either situation much.

The bike weighed 16 lbs, rider was 165 lbs and max power was 1350 watts.

Cheers,
Bret


Dear Bret,

It doesn't much matter whether we talk about a momentary acceleration
or steady-state cruising.

Heck, it doesn't much matter whether we're talking about a grandmother
setting off to the grocery store or a pro suddenly giving everything
he's got up the Alp d'Huez.

The mistaken belief that Newton's world changes dramatically for
really powerful riders or really steep hills keeps coming up in this
thread, so forgive me for ploughing through the same old stuff again.

***

160 + 16.0 = 176.0 lbs = 72.727 kg + 7.273 kg = 80.000 kg
160 + 17.5 = 177.5 lbs = 72.727 kg + 7.955 kg = 80.682 kg

177.5/176.0 = ~1.008, so acceleration should increase 1% in the real
world.

Sprint acceleration calculator:
http://www.analyticcycling.com/DiffE...n500_Page.html

First, let's see how much faster the 1.5-lb-lighter bike accelerates
from a standing start at 1350 watts up a convenient 8.1% stretch of
the Alp d'Huez.

Use max power 1350, avg power 1349.9, slope 0.081, and do it for a
distance of 10 meters (the very last field).

Then do it again for a max power of 100 watts and an average of 99.9.

1350 watts 100 watts
176.0 177.5 176.0 177.5
meters time time time time
1.0 0.3 0.3 1.1 1.1
2.5 0.6 0.6 2.4 2.4
5 1.2 1.2 4.2 4.2
10 2.1 2.1 7.6 7.6
15 2.8 2.8 10.9 11.0
20 3.3 3.3 14.3-14.4
25 3.9 3.9 17.6-17.8
50 6.4 6.4 34.4 34.7
100 10.6 10.7* 68.0 68.6
150 14.6 14.6 101.7 102.5
200 18.4 18.4 135.4 136.5
250 22.0-22.1 169.2 170.6
300 25.7-25.8 203.1 204.8

* shows how rounding can affect things

In other words, a 1.5-lb acceleration difference takes a long time up
an 8.1% grade to show up on a calculator that reads in tenths of a
second.

It takes 250 meters for a ~0.5% time difference to show up reliably on
a 0.1 second stopwatch for the powerful rider.

Neither rider is going to notice an off-the-line ~1% acceleration
increase with the seat of his pants.

If he's extrapolating from the change in how he can heave the 10%
lighter bike around, then he must have an impressive calculator inside
his head.

***

For steady-state cruising up the same hill, the speed differences are
even less than the acceleration differences.

Use 1350 watts, 8.1% grade, rider 160, bikes 16 and 17.6 lbs,
tubulars, hoods he
http://bikecalculator.com/veloUS.html

I get 27.99 mph versus 27.90 mph, 99.678% as fast. Once you accelerate
to cruising speed, the high speed wind drag effect reduces the ~1%
idealized mass difference to ~0.3%.

Now try grandma at 100 watts up the same 8.1% grade.

She goes 3.15 versus 3.17 mph.

***

As has been suggested, something besides the 1.5 lb frame difference
might account for the faster-from-the-first-pedal impression.

All of the technical possibilities (stiffer frame, different tires,
better aero, and so on) are dwarfed by the stubborn psychological
effect of trying a new bike.

Even the same thing with a different paint scheme will feel
"different" if we're told "go ahead and try this new [fill in the
blank]."

Trying something with an eye toward comparing it puts us in an
entirely different position than just using something familiar.

Cheers,

Carl Fogel
  #523  
Old July 18th 08, 11:40 PM posted to rec.bicycles.tech,rec.bicycles.racing
[email protected]
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Posts: 7,934
Default Steel frames and le Tour

On Fri, 18 Jul 2008 02:43:30 -0700, "Paul M. Hobson"
wrote:

wrote:
Dear Scott,

It's easy to lose track of such insignificant figures, so pardon this
correction.

In this sub-thread, the weight penalty was only 1 kg, 2.2 lbs, for an
imaginary elite rider putting out 400 watts up a 10% grade. It
produces a 0.18 km/h speed penalty, not the claimed 6 km/h.

My point was that the wildly exaggerated claim that 1 kg would slow a
pro down 6 km/h was absurd (and, as usual, presumably made in good
faith). To slow someone like that imaginary pro down 6 km/h with extra
weight on that climb, you have to perch an imaginary 50 kg podium girl
on his handlebar.


Carl:
What about another rider and bike?
http://tinyurl.com/6qo82g
g

\\paul


Dear Paul,

Nice photos!

The terrible thing is that Horner and his passenger would have passed
the likes of me up that hill.

Cheers,

Carl Fogel
  #524  
Old July 18th 08, 11:57 PM posted to rec.bicycles.tech,rec.bicycles.racing
Lou Holtman[_2_]
external usenet poster
 
Posts: 161
Default Steel frames and le Tour

wrote:
On Thu, 17 Jul 2008 23:08:40 -0600, Bret Wade
wrote:

wrote:
On Thu, 17 Jul 2008 14:13:43 -0600, Bret Wade
wrote:

wrote:

The original question was whether a rider can _feel_ such tiny
changes--that same old laughable "noticeably robust forward thrust."
I wouldn't put it in those words but I have felt that sensation when
switching from a 4 lb Ti frame to a 2.5 lb Al frame. It felt faster from
the first pedal stroke. It was a team bike that I was somewhat skeptical
of riding, so it wasn't just wishful thinking. Others on the team had
similar experiences. I understand physics well enough to know that the
sensation was misleading.

Bret
Dear Bret,

Forgive a long-winded answer, but you're so refreshingly reasonable
that I want to avoid any offense.

What interests me is the idea that a 1.5 lb lighter frame "felt faster
from the first pedal stroke"--possibly a generalization or even
hyperbole, but it's what we have to work with.

I don't know the actual weights, but it was a whole team, so a 150
pound rider and a 16.5 pound bike would probably be in the ballpark.

That theoretical 166.5 pound bike and rider would drop to 165 pounds,
about 0.9%.

The bike itself would have dropped from 16.5 to 15.0 pounds, about
10%.

The bike might twitch from side to side or heave forward 10% easier.

But I gather that we agree that the speed and acceleration
improvements are going to be so small that a calculator is necessary
to see them.

In fact, they don't show up on my first effort:
http://bikecalculator.com/veloUS.html

I tried 400 watts, a 150 pound rider, 15 and 16.5 pound bikes,
tubulars, and drops.

Because the calculator has only 2-decimal precision, both bikes went
the same speed--27.85 mph.

(A quick look at the time for 20 miles reassured me that the
calculator is still grinding out infinitesimal details--43.08 minutes
versus 43.09 minutes, a 0.01 minute lead, 0.6 seconds.)

Let's send the bikes up the Alp d'Huez, which I have handy at 8.1% and
13.8 km (8.56 miles):
http://en.wikipedia.org/wiki/Alpe_d'Huez

The steep grade teases out a speed difference, but it's still nothing
that a rider could detect.

I get 41.03 minutes versus 41.33, a 0.3 minute or 18 second lead after
almost 2500 seconds. That's ~1% faster.

The speeds are 12.52 mph versus 12.43 mph.

Raise the power to 500 watts, and the time and difference shrink to
34.04 versus 34.27, a little under 14 seconds, at 15.09 versus 14.99
mph.

In other words, it takes the Alp d'Huez and a light, world-class rider
to produce a tenth of a mile per hour and 14-second difference with a
1.5 pound lighter bike.

So I'm glad that you understand the physics well enough to know that
the impression was probably misleading. In unblinded testing, it's
hard to tell which way our misperceptions will go. Just paying
attention (because we're testing) distorts what we think we feel. Evil
psychologists love to demonstrate how students will mis-measure the
same lumber with the same measuring tapes, according to whether
they've been told that it's important for the boards not to be too
long, for them not to be too short, or that the measurement accuracy
does (or doesn't) really matter.

Cheers,

Carl Fogel

Dear Carl,

No need to apologize, I understand that bad habits can be hard to break.
The hardest thing I've done in my life is break a pack a day Marlboro habit.

Anyway, I'll just point out that your very detailed analysis involves
steady state aerobic climbing whereas most "Wow, this bike is fast!"
moments will come during anaerobic accelerations. Not that I think the
result would be much different. A small change in total mass won't
affect either situation much.

The bike weighed 16 lbs, rider was 165 lbs and max power was 1350 watts.

Cheers,
Bret


Dear Bret,

It doesn't much matter whether we talk about a momentary acceleration
or steady-state cruising.

Heck, it doesn't much matter whether we're talking about a grandmother
setting off to the grocery store or a pro suddenly giving everything
he's got up the Alp d'Huez.

The mistaken belief that Newton's world changes dramatically for
really powerful riders or really steep hills keeps coming up in this
thread, so forgive me for ploughing through the same old stuff again.

***

160 + 16.0 = 176.0 lbs = 72.727 kg + 7.273 kg = 80.000 kg
160 + 17.5 = 177.5 lbs = 72.727 kg + 7.955 kg = 80.682 kg

177.5/176.0 = ~1.008, so acceleration should increase 1% in the real
world.

Sprint acceleration calculator:
http://www.analyticcycling.com/DiffE...n500_Page.html

First, let's see how much faster the 1.5-lb-lighter bike accelerates
from a standing start at 1350 watts up a convenient 8.1% stretch of
the Alp d'Huez.

Use max power 1350, avg power 1349.9, slope 0.081, and do it for a
distance of 10 meters (the very last field).

Then do it again for a max power of 100 watts and an average of 99.9.

1350 watts 100 watts
176.0 177.5 176.0 177.5
meters time time time time
1.0 0.3 0.3 1.1 1.1
2.5 0.6 0.6 2.4 2.4
5 1.2 1.2 4.2 4.2
10 2.1 2.1 7.6 7.6
15 2.8 2.8 10.9 11.0
20 3.3 3.3 14.3-14.4
25 3.9 3.9 17.6-17.8
50 6.4 6.4 34.4 34.7
100 10.6 10.7* 68.0 68.6
150 14.6 14.6 101.7 102.5
200 18.4 18.4 135.4 136.5
250 22.0-22.1 169.2 170.6
300 25.7-25.8 203.1 204.8

* shows how rounding can affect things

In other words, a 1.5-lb acceleration difference takes a long time up
an 8.1% grade to show up on a calculator that reads in tenths of a
second.

It takes 250 meters for a ~0.5% time difference to show up reliably on
a 0.1 second stopwatch for the powerful rider.

Neither rider is going to notice an off-the-line ~1% acceleration
increase with the seat of his pants.

If he's extrapolating from the change in how he can heave the 10%
lighter bike around, then he must have an impressive calculator inside
his head.

***

For steady-state cruising up the same hill, the speed differences are
even less than the acceleration differences.

Use 1350 watts, 8.1% grade, rider 160, bikes 16 and 17.6 lbs,
tubulars, hoods he
http://bikecalculator.com/veloUS.html

I get 27.99 mph versus 27.90 mph, 99.678% as fast. Once you accelerate
to cruising speed, the high speed wind drag effect reduces the ~1%
idealized mass difference to ~0.3%.

Now try grandma at 100 watts up the same 8.1% grade.

She goes 3.15 versus 3.17 mph.

***

As has been suggested, something besides the 1.5 lb frame difference
might account for the faster-from-the-first-pedal impression.

All of the technical possibilities (stiffer frame, different tires,
better aero, and so on) are dwarfed by the stubborn psychological
effect of trying a new bike.

Even the same thing with a different paint scheme will feel
"different" if we're told "go ahead and try this new [fill in the
blank]."

Trying something with an eye toward comparing it puts us in an
entirely different position than just using something familiar.

Cheers,

Carl Fogel



You can stop now Carl. You take away peoples illusions and beliefs with
your straightforward calculation. I someway this ****es them off. You
are arguing now with people who don't want to belief. No point in that.
'...... anaerobic accelerations.....' Geezes what crap is that?

Lou
  #525  
Old July 19th 08, 12:16 AM posted to rec.bicycles.tech,rec.bicycles.racing
Tom Kunich
external usenet poster
 
Posts: 6,456
Default Steel frames and le Tour

wrote in message
...
On Jul 17, 4:10 pm, "Tom Kunich" cyclintom@yahoo. com wrote:

And the total savings a My Time VX costs almost 4 times more than my
Basso Loto and they ride almost identically and weigh within a lb of each
other.


I used to have a Basso Ascot. It was my favorite bike ever. It died in
a collision with a car and I didn't do too well either. It was a great
frame, though. I think that it was the geometry that made the bike
feel really nice. I don't know if your Lotto has the same geometry as
my Ascot, but if it does, I know why you like it. I am sure that I
will also be able to get a great ride with frames of different
materials that have the same geometry as my Ascot. A lot of the times,
a cyclist may like a bike more because the geometry makes it feel
faster.

I believe , like Carl, that the feeling is just that and your speed
does not necessarily increase or decrease that much. However, it is
great to ride on a bike that has "that" feeling.


I had a Basso Gap as my first high end bike and it was a great bike after I
replaced the new Dura Ace headset with a new Campy headset that didn't have
a high speed wobble...

I'm tall - 6'4" and ride a 61 or 62 cm bike and some other VERY famous bikes
ride like crap in these sizes. I've had a large collection of increasingly
expensive bikes and yet none of them are any better than the Basso. Though
some of them are just as good.

The Bassos have always been good to me.

  #526  
Old July 19th 08, 01:06 AM posted to rec.bicycles.tech,rec.bicycles.racing
SLAVE of THE STATE
external usenet poster
 
Posts: 1,774
Default Steel frames and le Tour

On Jul 18, 3:57*pm, Lou Holtman wrote:

'...... anaerobic accelerations.....' Geezes what crap is that?


Are you retarded?

If someone goes from a "cruise" of say 100W, then up to an
unsustainable peak of 1350W, and with any reasonable probability the
speed increased, what would you like to call it?

  #527  
Old July 19th 08, 02:56 AM posted to rec.bicycles.tech,rec.bicycles.racing
Bret Wade[_2_]
external usenet poster
 
Posts: 172
Default Steel frames and le Tour

Lou Holtman wrote:
wrote:
On Thu, 17 Jul 2008 23:08:40 -0600, Bret Wade
wrote:

wrote:
On Thu, 17 Jul 2008 14:13:43 -0600, Bret Wade
wrote:

wrote:

The original question was whether a rider can _feel_ such tiny
changes--that same old laughable "noticeably robust forward thrust."
I wouldn't put it in those words but I have felt that sensation
when switching from a 4 lb Ti frame to a 2.5 lb Al frame. It felt
faster from the first pedal stroke. It was a team bike that I was
somewhat skeptical of riding, so it wasn't just wishful thinking.
Others on the team had similar experiences. I understand physics
well enough to know that the sensation was misleading.

Bret
Dear Bret,

Forgive a long-winded answer, but you're so refreshingly reasonable
that I want to avoid any offense.

What interests me is the idea that a 1.5 lb lighter frame "felt faster
from the first pedal stroke"--possibly a generalization or even
hyperbole, but it's what we have to work with.

I don't know the actual weights, but it was a whole team, so a 150
pound rider and a 16.5 pound bike would probably be in the ballpark.

That theoretical 166.5 pound bike and rider would drop to 165 pounds,
about 0.9%.

The bike itself would have dropped from 16.5 to 15.0 pounds, about
10%.

The bike might twitch from side to side or heave forward 10% easier.

But I gather that we agree that the speed and acceleration
improvements are going to be so small that a calculator is necessary
to see them.

In fact, they don't show up on my first effort:
http://bikecalculator.com/veloUS.html

I tried 400 watts, a 150 pound rider, 15 and 16.5 pound bikes,
tubulars, and drops.

Because the calculator has only 2-decimal precision, both bikes went
the same speed--27.85 mph.

(A quick look at the time for 20 miles reassured me that the
calculator is still grinding out infinitesimal details--43.08 minutes
versus 43.09 minutes, a 0.01 minute lead, 0.6 seconds.)

Let's send the bikes up the Alp d'Huez, which I have handy at 8.1% and
13.8 km (8.56 miles):
http://en.wikipedia.org/wiki/Alpe_d'Huez

The steep grade teases out a speed difference, but it's still nothing
that a rider could detect.

I get 41.03 minutes versus 41.33, a 0.3 minute or 18 second lead after
almost 2500 seconds. That's ~1% faster.

The speeds are 12.52 mph versus 12.43 mph.

Raise the power to 500 watts, and the time and difference shrink to
34.04 versus 34.27, a little under 14 seconds, at 15.09 versus 14.99
mph.

In other words, it takes the Alp d'Huez and a light, world-class rider
to produce a tenth of a mile per hour and 14-second difference with a
1.5 pound lighter bike.

So I'm glad that you understand the physics well enough to know that
the impression was probably misleading. In unblinded testing, it's
hard to tell which way our misperceptions will go. Just paying
attention (because we're testing) distorts what we think we feel. Evil
psychologists love to demonstrate how students will mis-measure the
same lumber with the same measuring tapes, according to whether
they've been told that it's important for the boards not to be too
long, for them not to be too short, or that the measurement accuracy
does (or doesn't) really matter.

Cheers,

Carl Fogel
Dear Carl,

No need to apologize, I understand that bad habits can be hard to
break. The hardest thing I've done in my life is break a pack a day
Marlboro habit.

Anyway, I'll just point out that your very detailed analysis involves
steady state aerobic climbing whereas most "Wow, this bike is fast!"
moments will come during anaerobic accelerations. Not that I think
the result would be much different. A small change in total mass
won't affect either situation much.

The bike weighed 16 lbs, rider was 165 lbs and max power was 1350 watts.

Cheers,
Bret


Dear Bret,

It doesn't much matter whether we talk about a momentary acceleration
or steady-state cruising.

Heck, it doesn't much matter whether we're talking about a grandmother
setting off to the grocery store or a pro suddenly giving everything
he's got up the Alp d'Huez.
The mistaken belief that Newton's world changes dramatically for
really powerful riders or really steep hills keeps coming up in this
thread, so forgive me for ploughing through the same old stuff again.

***

160 + 16.0 = 176.0 lbs = 72.727 kg + 7.273 kg = 80.000 kg 160 + 17.5
= 177.5 lbs = 72.727 kg + 7.955 kg = 80.682 kg

177.5/176.0 = ~1.008, so acceleration should increase 1% in the real
world.

Sprint acceleration calculator:
http://www.analyticcycling.com/DiffE...n500_Page.html

First, let's see how much faster the 1.5-lb-lighter bike accelerates
from a standing start at 1350 watts up a convenient 8.1% stretch of
the Alp d'Huez.

Use max power 1350, avg power 1349.9, slope 0.081, and do it for a
distance of 10 meters (the very last field).

Then do it again for a max power of 100 watts and an average of 99.9.

1350 watts 100 watts
176.0 177.5 176.0 177.5
meters time time time time
1.0 0.3 0.3 1.1 1.1
2.5 0.6 0.6 2.4 2.4
5 1.2 1.2 4.2 4.2
10 2.1 2.1 7.6 7.6
15 2.8 2.8 10.9 11.0
20 3.3 3.3 14.3-14.4
25 3.9 3.9 17.6-17.8
50 6.4 6.4 34.4 34.7
100 10.6 10.7* 68.0 68.6
150 14.6 14.6 101.7 102.5
200 18.4 18.4 135.4 136.5
250 22.0-22.1 169.2 170.6
300 25.7-25.8 203.1 204.8

* shows how rounding can affect things

In other words, a 1.5-lb acceleration difference takes a long time up
an 8.1% grade to show up on a calculator that reads in tenths of a
second.

It takes 250 meters for a ~0.5% time difference to show up reliably on
a 0.1 second stopwatch for the powerful rider.

Neither rider is going to notice an off-the-line ~1% acceleration
increase with the seat of his pants.

If he's extrapolating from the change in how he can heave the 10%
lighter bike around, then he must have an impressive calculator inside
his head.

***

For steady-state cruising up the same hill, the speed differences are
even less than the acceleration differences.

Use 1350 watts, 8.1% grade, rider 160, bikes 16 and 17.6 lbs,
tubulars, hoods he
http://bikecalculator.com/veloUS.html

I get 27.99 mph versus 27.90 mph, 99.678% as fast. Once you accelerate
to cruising speed, the high speed wind drag effect reduces the ~1%
idealized mass difference to ~0.3%.

Now try grandma at 100 watts up the same 8.1% grade.

She goes 3.15 versus 3.17 mph.

***

As has been suggested, something besides the 1.5 lb frame difference
might account for the faster-from-the-first-pedal impression.

All of the technical possibilities (stiffer frame, different tires,
better aero, and so on) are dwarfed by the stubborn psychological
effect of trying a new bike.

Even the same thing with a different paint scheme will feel
"different" if we're told "go ahead and try this new [fill in the
blank]."
Trying something with an eye toward comparing it puts us in an
entirely different position than just using something familiar.

Cheers,

Carl Fogel



You can stop now Carl. You take away peoples illusions and beliefs with
your straightforward calculation.


What illusions? I specifically said that a small change in mass doesn't
have much affect.

I someway this ****es them off.


I'm not mad.

You are arguing now with people who don't want to belief.


We're not arguing.

No point in that.


No.

'...... anaerobic accelerations.....' Geezes what crap is that?


That crap is the **** that will kill them in uphill sprint finishes.

Bret
  #528  
Old July 19th 08, 03:24 AM posted to rec.bicycles.tech,rec.bicycles.racing
[email protected]
external usenet poster
 
Posts: 7,934
Default Steel frames and le Tour

On Fri, 18 Jul 2008 14:40:56 -0700 (PDT), "
wrote:

On Jul 17, 4:10 pm, "Tom Kunich" cyclintom@yahoo. com wrote:
"Tuschinski" wrote in message

...



And indeed when you look at the actual numbers of
failures you find that a correctly built steel frame, even superlight
ones,
very seldom fail and when they do it is pretty plainly a workmanship or
material error.


Oh come on Tom, that's blatantly false. Back in the days, when we all
raced Reynolds/Columbus we broke frames. Some of it by crashing, some
by bad handling, some by bad manufacturers.


And yes, we also broke Alu frames. And now we break CF frames
*shrug*.


Such is life ^^


I don't follow you here. Well built steel frames seldom fail. Well built AL
frames (the super light ones) fail whether you take good care of them or
not. I have personally observed quite a few carbon fiber failures and these
bikes are EXPENSIVE.

And the total savings a My Time VX costs almost 4 times more than my
Basso Loto and they ride almost identically and weigh within a lb of each
other.


I used to have a Basso Ascot. It was my favorite bike ever. It died in
a collision with a car and I didn't do too well either. It was a great
frame, though. I think that it was the geometry that made the bike
feel really nice. I don't know if your Lotto has the same geometry as
my Ascot, but if it does, I know why you like it. I am sure that I
will also be able to get a great ride with frames of different
materials that have the same geometry as my Ascot. A lot of the times,
a cyclist may like a bike more because the geometry makes it feel
faster.

I believe , like Carl, that the feeling is just that and your speed
does not necessarily increase or decrease that much. However, it is
great to ride on a bike that has "that" feeling.

Andres


Dear Andres,

The day after I removed the 7 pounds of weights from my bike, I went
for my usual afternoon ride.

I didn't notice any surge in speed or acceleration when I lost the 7
pounds.

In fact, I didn't even have a twinge of boy-I'd-like-a-lighter-bike!

I suspect that a whole new bike might have felt (and looked) different
enough in various ways (tires, wheels, geometry, saddle, brakes, and
so on) to make me easy prey for a salesman.

But just strapping the extra weight onto the same old bike without
changing anything else left me with nothing more than the very suspect
feeling that the bike felt "heavier".

Much of that "heavier" feeling was probably just the vibration damping
of the extra rubber-encased 7 pounds on the top tube. (After all, it
amounted to only a 3.2% weight increase.)

The rest of the "heavier" feeling was probably due to all the extra
attention that I paid (does it feel heavier? lighter? how does it
normally feel?), plus the unavoidable knowledge that there were
_seven_ whole pounds sitting right there in plain sight whenever I
looked down at the speedometer.

Some posters might want to try the experiment of just adding a few
extra pounds to their familiar bike and comparing whatever difference
they "feel" to whatever happens to their actual times around a
familiar route.

Cheers,

Carl Fogel
  #529  
Old July 19th 08, 03:53 AM posted to rec.bicycles.tech,rec.bicycles.racing
Tom Kunich
external usenet poster
 
Posts: 6,456
Default Steel frames and le Tour

"Bret Wade" wrote in message
m...
Lou Holtman wrote:

You can stop now Carl. You take away peoples illusions and beliefs with
your straightforward calculation.


What illusions? I specifically said that a small change in mass doesn't
have much affect.

I someway this ****es them off.


I'm not mad.

You are arguing now with people who don't want to belief.


We're not arguing.

No point in that.


No.

'...... anaerobic accelerations.....' Geezes what crap is that?


That crap is the **** that will kill them in uphill sprint finishes.


Seems to be sort of weird that the people claiming the math explains
everything are those who don't seem able to understand the entire point of
the conversation.



  #530  
Old July 19th 08, 03:54 AM posted to rec.bicycles.tech,rec.bicycles.racing
[email protected]
external usenet poster
 
Posts: 7,934
Default Steel frames and le Tour

On Sat, 19 Jul 2008 00:57:07 +0200, Lou Holtman
wrote:

wrote:
On Thu, 17 Jul 2008 23:08:40 -0600, Bret Wade
wrote:

wrote:
On Thu, 17 Jul 2008 14:13:43 -0600, Bret Wade
wrote:

wrote:

The original question was whether a rider can _feel_ such tiny
changes--that same old laughable "noticeably robust forward thrust."
I wouldn't put it in those words but I have felt that sensation when
switching from a 4 lb Ti frame to a 2.5 lb Al frame. It felt faster from
the first pedal stroke. It was a team bike that I was somewhat skeptical
of riding, so it wasn't just wishful thinking. Others on the team had
similar experiences. I understand physics well enough to know that the
sensation was misleading.

Bret
Dear Bret,

Forgive a long-winded answer, but you're so refreshingly reasonable
that I want to avoid any offense.

What interests me is the idea that a 1.5 lb lighter frame "felt faster
from the first pedal stroke"--possibly a generalization or even
hyperbole, but it's what we have to work with.

I don't know the actual weights, but it was a whole team, so a 150
pound rider and a 16.5 pound bike would probably be in the ballpark.

That theoretical 166.5 pound bike and rider would drop to 165 pounds,
about 0.9%.

The bike itself would have dropped from 16.5 to 15.0 pounds, about
10%.

The bike might twitch from side to side or heave forward 10% easier.

But I gather that we agree that the speed and acceleration
improvements are going to be so small that a calculator is necessary
to see them.

In fact, they don't show up on my first effort:
http://bikecalculator.com/veloUS.html

I tried 400 watts, a 150 pound rider, 15 and 16.5 pound bikes,
tubulars, and drops.

Because the calculator has only 2-decimal precision, both bikes went
the same speed--27.85 mph.

(A quick look at the time for 20 miles reassured me that the
calculator is still grinding out infinitesimal details--43.08 minutes
versus 43.09 minutes, a 0.01 minute lead, 0.6 seconds.)

Let's send the bikes up the Alp d'Huez, which I have handy at 8.1% and
13.8 km (8.56 miles):
http://en.wikipedia.org/wiki/Alpe_d'Huez

The steep grade teases out a speed difference, but it's still nothing
that a rider could detect.

I get 41.03 minutes versus 41.33, a 0.3 minute or 18 second lead after
almost 2500 seconds. That's ~1% faster.

The speeds are 12.52 mph versus 12.43 mph.

Raise the power to 500 watts, and the time and difference shrink to
34.04 versus 34.27, a little under 14 seconds, at 15.09 versus 14.99
mph.

In other words, it takes the Alp d'Huez and a light, world-class rider
to produce a tenth of a mile per hour and 14-second difference with a
1.5 pound lighter bike.

So I'm glad that you understand the physics well enough to know that
the impression was probably misleading. In unblinded testing, it's
hard to tell which way our misperceptions will go. Just paying
attention (because we're testing) distorts what we think we feel. Evil
psychologists love to demonstrate how students will mis-measure the
same lumber with the same measuring tapes, according to whether
they've been told that it's important for the boards not to be too
long, for them not to be too short, or that the measurement accuracy
does (or doesn't) really matter.

Cheers,

Carl Fogel
Dear Carl,

No need to apologize, I understand that bad habits can be hard to break.
The hardest thing I've done in my life is break a pack a day Marlboro habit.

Anyway, I'll just point out that your very detailed analysis involves
steady state aerobic climbing whereas most "Wow, this bike is fast!"
moments will come during anaerobic accelerations. Not that I think the
result would be much different. A small change in total mass won't
affect either situation much.

The bike weighed 16 lbs, rider was 165 lbs and max power was 1350 watts.

Cheers,
Bret


Dear Bret,

It doesn't much matter whether we talk about a momentary acceleration
or steady-state cruising.

Heck, it doesn't much matter whether we're talking about a grandmother
setting off to the grocery store or a pro suddenly giving everything
he's got up the Alp d'Huez.

The mistaken belief that Newton's world changes dramatically for
really powerful riders or really steep hills keeps coming up in this
thread, so forgive me for ploughing through the same old stuff again.

***

160 + 16.0 = 176.0 lbs = 72.727 kg + 7.273 kg = 80.000 kg
160 + 17.5 = 177.5 lbs = 72.727 kg + 7.955 kg = 80.682 kg

177.5/176.0 = ~1.008, so acceleration should increase 1% in the real
world.

Sprint acceleration calculator:
http://www.analyticcycling.com/DiffE...n500_Page.html

First, let's see how much faster the 1.5-lb-lighter bike accelerates
from a standing start at 1350 watts up a convenient 8.1% stretch of
the Alp d'Huez.

Use max power 1350, avg power 1349.9, slope 0.081, and do it for a
distance of 10 meters (the very last field).

Then do it again for a max power of 100 watts and an average of 99.9.

1350 watts 100 watts
176.0 177.5 176.0 177.5
meters time time time time
1.0 0.3 0.3 1.1 1.1
2.5 0.6 0.6 2.4 2.4
5 1.2 1.2 4.2 4.2
10 2.1 2.1 7.6 7.6
15 2.8 2.8 10.9 11.0
20 3.3 3.3 14.3-14.4
25 3.9 3.9 17.6-17.8
50 6.4 6.4 34.4 34.7
100 10.6 10.7* 68.0 68.6
150 14.6 14.6 101.7 102.5
200 18.4 18.4 135.4 136.5
250 22.0-22.1 169.2 170.6
300 25.7-25.8 203.1 204.8

* shows how rounding can affect things

In other words, a 1.5-lb acceleration difference takes a long time up
an 8.1% grade to show up on a calculator that reads in tenths of a
second.

It takes 250 meters for a ~0.5% time difference to show up reliably on
a 0.1 second stopwatch for the powerful rider.

Neither rider is going to notice an off-the-line ~1% acceleration
increase with the seat of his pants.

If he's extrapolating from the change in how he can heave the 10%
lighter bike around, then he must have an impressive calculator inside
his head.

***

For steady-state cruising up the same hill, the speed differences are
even less than the acceleration differences.

Use 1350 watts, 8.1% grade, rider 160, bikes 16 and 17.6 lbs,
tubulars, hoods he
http://bikecalculator.com/veloUS.html

I get 27.99 mph versus 27.90 mph, 99.678% as fast. Once you accelerate
to cruising speed, the high speed wind drag effect reduces the ~1%
idealized mass difference to ~0.3%.

Now try grandma at 100 watts up the same 8.1% grade.

She goes 3.15 versus 3.17 mph.

***

As has been suggested, something besides the 1.5 lb frame difference
might account for the faster-from-the-first-pedal impression.

All of the technical possibilities (stiffer frame, different tires,
better aero, and so on) are dwarfed by the stubborn psychological
effect of trying a new bike.

Even the same thing with a different paint scheme will feel
"different" if we're told "go ahead and try this new [fill in the
blank]."

Trying something with an eye toward comparing it puts us in an
entirely different position than just using something familiar.

Cheers,

Carl Fogel



You can stop now Carl. You take away peoples illusions and beliefs with
your straightforward calculation. I someway this ****es them off. You
are arguing now with people who don't want to belief. No point in that.
'...... anaerobic accelerations.....' Geezes what crap is that?

Lou


Dear Lou,

Well, it's the kind of thing that I'd have come up with myself before
I looked into things.

Bret seems quite reasonable to me. He felt _something_ different, and
so did his whole team, so if it doesn't make sense with 350 watt
examples, maybe it was because of the 1350 watt sprint?

Until you work through some of these things, it's normal to think that
a lot of power or a really steep hill or a standing start or
_something_ will explain all the big jumps and falling-off-the-back
and other things that seem so obvious.

Remember, it took an awfully long time before people decided that
hefty objects dropped from a tower fall at about the same rate. And we
still have to explain on RBT that heavier riders coast downhill faster
because the power from gravity pulling on their extra mass rises
faster than their wind drag does.

That's why I keep working through the examples suggested by other
posters. (I keep wondering why they don't try playing with the
calculators themselves--it's not that hard.)

What if the Alp d'Huez really did produce a dramatically different
result for 7 extra pounds? What if a 1200-foot climb in 2.9 miles
somehow exaggerated the effect of extra weight? Does a 1350 watt burst
by a sprinter change the outcome that a 350 watt rider will see?

It turns out that F = M * A is dreadfully stubborn.

Armstrong could have carried a 7-lb handicap up the Alp d'Huez before
he slowed down to Ullrich's speed.

People really do see jumps, but they're due to either massively
mismatched power or one rider jumping a fraction of a second ahead of
the other, not 1, 2.2, or even 7-lb weight differences. The greater
the power, the _less_ the actual difference because wind drag isn't
linear.

Riders do fall off the back. But if you can't keep up while drafting
on the flats, you certainly haven't got the power to pull ahead.

They usually fall off when the pack hits a climb. The guys in back
have been hanging on because they could keep up while putting out 10%
to 20% less power. That advantage dwindles rapidly as the pack slows
down on the hill. That's when the guys who were in front show the real
power difference and pull away. That's why it's called being
"dropped"--they don't just creep away at 180 meters per hour (0.18
km/h), they pull away at ten times that speed (a whopping 1.8 km/h,
which should remind us how tiny the differences are in bicycling).

When that happens, it's human to blame it on the extra weight. After
all, every bicycle magazine and article weighs every part to the
nearest gram.

I expect that many posters believe in good faith that they're feeling
speed or acceleration when they're just feeling how much easier a
lighter bike is to heave back and forth and tip side to side. That
feeling is an order of magnitude greater than the acceleration or
speed change, so it's hard reason yourself out of it. An analogy would
be how fast does 75 mph feel on the highway? In a bouncy short
wheelbase jeep with deep-tread tires, 75 mph feels much "faster" than
the same 75 mph in a limousine (or 500 mph in a jetliner).

Cheers,

Carl Fogel
 




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