Steel frames and le Tour

John Forrest Tomlinson wrote:
On Mon, 14 Jul 2008 00:37:34 -0700 (PDT), hizark21
wrote:

But
this illustrate how easily composite frames are damaged.

But they're not. You just don't get it.

Here's another example: a friend of mine was riding around warming up
at a race. He did a few sprints and something didn't feel right. He
looked carefully at the bike and saw the downtube was cracked.

Does that prove anything? The bike may/probably was damaged in an
earlier crash. So what?

Oh, byt the way, this was 1983 and the frame was Columbus SL.

Just so you know John, this anecdote only supports the CFRP naysayers
who prefer steel because it's failure is slow and noticeable -- not
catastrophic.

\\paul

--
Paul M. Hobson
..:change the f to ph to reply:.

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

carlfogel wrote:
My lighter keyboard provided the crucial margin of victory.

http://carcino.gen.nz/images/index.p...9a680/463c5922

SLAVE of THE STATE wrote:
Hi. Maybe I get your point. For example, your head is 100% up your ass.
But you seem not to sense it.

Or 98% or perhaps 102%.

wrote:
Keep up the good work! By the end of the Tour, you'll be ready for a full
12 month tour of duty in RBR.

You mean we're entitled to veteran benefits (unless McCain wins).

On Jul 18, 12:51 am, Donald Munro wrote:
wrote:
Keep up the good work! By the end of the Tour, you'll be ready for a full
12 month tour of duty in RBR.

You mean we're entitled to veteran benefits (unless McCain wins).

Google "stop loss policy". Sucker.


Ben
"The next day Colonel Cathcart was there, brimming
with tough pride in his new outfit and celebrating
his assumption of command by raising the number of
missions required from 25 to 30. Hungry Joe unpacked
his bags and rewrote the happy letters home."
-- Joseph Heller

wrote:
Keep up the good work! By the end of the Tour, you'll be ready for a
full 12 month tour of duty in RBR.

Donald Munro wrote:
You mean we're entitled to veteran benefits (unless McCain wins).

wrote:
"The next day Colonel Cathcart was there, brimming with tough pride in his
new outfit and celebrating his assumption of command by raising the number
of missions required from 25 to 30. Hungry Joe unpacked his bags and
rewrote the happy letters home."
-- Joseph Heller

I knew there'd be a catch.

On Sun, 13 Jul 2008 11:52:58 -0700 (PDT), Scott
wrote in regards
to steel frames in Le Tour de France:
I said I wouldn't be surprised if someone
were doing it this year. That's all. I wouldn't be surprised.

For some silly-ass reason, YOU decide to chime in to tell me, in
essence, I'm stupid for making my comment. Who's the asshole?

John Forrest Tomlinson wrote:
I said you'd be wrong. If you take that as meaning I was calling you
stupid, then that's your interpretation.

Wait, he's wrong that he wouldn't be surprised?

--
Paul M. Hobson
..:change the f to ph to reply:.

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
--
Paul M. Hobson
..:change the f to ph to reply:.

Tom Kunich wrote:
What's really funny is that Munro probably hasn't seen a race in 10
years.

"Donald Munro" wrote in message
SchwartzSoft the insult generator in the TOM9000 upgrade is useless, worse
than an XP to Vista upgrade. The competition is going to kill you during
the election season.

On Jul 16, 1:45 pm, "Tom Kunich" cyclintom@yahoo. com wrote:
Anyone else notice that he didn't dispute my guess?

SLAVE of THE STATE wrote:
Isn't Great Britain an island off the coast of Australia, another but
bigger island?

Anyway, from what I hear, there are no bike races in Britain, so we
can hardly fault Mr. Munro.

Didn't some French dudes have a race there about a year ago?

\\paul

--
Paul M. Hobson
..:change the f to ph to reply:.