Steel frames and le Tour

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 ^^

On 14 jul, 02:10, A Muzi wrote:
"Lou Holtman" wrote
There are lots of examples of broken steel frames too. In fatigue
tests steel frames almost always break first.
Tom Kunich wrote:
But when they're running these tests they greatly overload these frames
in order to force failures. Because of the nature of steel this isn't an
honest test of their reliability. 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.

In steel frame failures, crashes overshadow defects, both material and
workmanship, by a large margin.

Most steel frame errors we see are benign, that is, we find a
half-flowed joint or lousy miter or a tube in backwards when doing other
unrelated repairs. The dramatic ones, such as fork tip held in by paint
or a column loose in crown ("braze omission") are quite rare.

Of surviving steel builders, defects seem to be much less frequent than
in the last century, just like every other manufactured thing (go Deming!).
--
Andrew Muzi
* www.yellowjersey.org/
* Open every day since 1 April, 1971
** Posted fromhttp://www.teranews.com**

Andrew, is that due to workmanship?

Or is it due to steel bikes not being raced competitvely so often,
where crashes are more common?
Or is it due to a smaller sample, so it doesnt show up so blatantly?

I'm not really doubting you here, just three uestions that pop up.

Btw, repairing a steel frame isn't THAT straight forward, it is only
cost effective if the frame itself is above a certain price (my own
experience, so anecdotical i guess^^). Not that many people who can
refit a tube/lug and being cheap about it^^.

On Jul 17, 1:47*am, wrote:
On Wed, 16 Jul 2008 19:00:39 -0700, "Off The Back"
wrote:
That's not much of a climb over 15 miles, and I certainly agree with your
point that the impact of bike mass is not very significant for steady-state
riding on mostly flat terrain, compared to other factors. But...

...I regularly ride a 1,200 ft climb (2.9 miles long) and am pretty
confident that I could detect the *effect* of a 7-lb difference in my bike.
And I'm positive I could detect the mass difference because of the change in
the bike's characteristics moving side-to-side and fore-and-aft beneath me.
I'd put money on it.

Mark
http://marcofanelli.blogspot.com

Dear Mark,

Hang on to your money.

*:-)

Again, the original question was whether a rider could detect a
"noticeably robust forward thrust" with a bike 7 pounds lighter.

Not side-to-side tipping, not handling, not how it feels when hefted
or rolled forward while walking next to it, not how it vibrates, but
how it _accelerates_.


Dear Carl:

A gentleman, if prudence requires him to decline
a wager, does not do it with the phrase
"Hang on to your money."

Mark asserted that he would be able to detect the
difference in the dynamic handling of the bike, and
that was the "bet" he made. The calculations you
showed do nothing to disprove this. Admittedly,
it would be hard to disprove, and thus hard to
adjudicate the bet, but you could simply say that
rather than pontificating at length and redefining the
question to be about your assertion rather than
Mark's.

For what it's worth, I think there are three places
where bike weight really matters:
1) You're riding up Alpe d'Huez
2) You race cyclocross.
3) You live in a third-floor walkup apartment.

While in any of these cases you might not be able
to feel the extra 7 lb in a blind test, it still matters.

Ben

On Jul 17, 10:47*am, "
wrote:
On Jul 17, 1:47*am, wrote:





On Wed, 16 Jul 2008 19:00:39 -0700, "Off The Back"
wrote:
That's not much of a climb over 15 miles, and I certainly agree with your
point that the impact of bike mass is not very significant for steady-state
riding on mostly flat terrain, compared to other factors. But...

...I regularly ride a 1,200 ft climb (2.9 miles long) and am pretty
confident that I could detect the *effect* of a 7-lb difference in my bike.
And I'm positive I could detect the mass difference because of the change in
the bike's characteristics moving side-to-side and fore-and-aft beneath me.
I'd put money on it.

Mark
http://marcofanelli.blogspot.com

Dear Mark,

Hang on to your money.

*:-)

Again, the original question was whether a rider could detect a
"noticeably robust forward thrust" with a bike 7 pounds lighter.

Not side-to-side tipping, not handling, not how it feels when hefted
or rolled forward while walking next to it, not how it vibrates, but
how it _accelerates_.

Dear Carl:

A gentleman, if prudence requires him to decline
a wager, does not do it with the phrase
"Hang on to your money."

dumbass-

He put in a smiley face. Doesn't that change everything?

It was that little 2% of extra ascii that made me really feel the
difference.

On Thu, 17 Jul 2008 05:54:22 -0700, jim beam
wrote:

wrote:
snip for clarity


Again, many indignant posters are confusing what they can detect by
tipping a bike, watching a reference rider,

ok, stop right there - yes, "watching" a reference rider. that's what
it's all about carl - being able to better the other guy.

[snip]

Dear Jim,

Sorry, that's not what it's all about.

The original question was whether a rider can _feel_ such tiny
changes--that same old laughable "noticeably robust forward thrust."

He can't, so lots of posters are frothing about everything else, with
nothing but bluster.

Cheers,

Carl Fogel

On Thu, 17 Jul 2008 09:31:08 GMT, John Forrest Tomlinson
wrote:

On Thu, 17 Jul 2008 02:58:44 -0600, wrote:



Dear John,

In other words, you embarrassed yourself by replying to my one-line
post with the complaint that I'm long winded.


In other words, you're still long-winded

Dear John,

Ah, so two lines to explain things to you for the umpteenth time is
long-winded!

I doubt you'll get to this second line, any more than your attention
span encompassed the thread where I did the test that you kept begging
for--you know, the one that you're afraid to do.

Cheers,

Carl Fogel

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

On Thu, 17 Jul 2008 09:27:44 -0700, "Off The Back"
wrote:

carlfogel wrote:
carl fogel wrote:
snip
Consider how trivial adding 7 pounds to the total weight is, compared
to the other factors that produced a 3 minute variation in 7
consecutive daily ride of ~46-49 minutes on 15.1 mile loop with a
400-foot climb. snip

That's not much of a climb over 15 miles, and I certainly agree with your
point that the impact of bike mass is not very significant for
steady-state
riding on mostly flat terrain, compared to other factors. But...

...I regularly ride a 1,200 ft climb (2.9 miles long) and am pretty
confident that I could detect the *effect* of a 7-lb difference in my
bike.
And I'm positive I could detect the mass difference because of the change
in
the bike's characteristics moving side-to-side and fore-and-aft beneath
me.
I'd put money on it.

Mark
http://marcofanelli.blogspot.com

Dear Mark,

Hang on to your money.

:-)

Again, the original question was whether a rider could detect a
"noticeably robust forward thrust" with a bike 7 pounds lighter.

Not side-to-side tipping, not handling, not how it feels when hefted
or rolled forward while walking next to it, not how it vibrates, but
how it _accelerates_.
snipped the physics lesson which I already understand

I'm glad at least that you agree that the side-to-side differences are
detectable. But think also about the periodic axial accelerations you and
your bike experience even when climbing at a steady-state *average* speed.
On slopes of any significance, these periodic accelerations correspond with
your pedal strokes. Anybody who climbs a lot develops a definite feel for
that dynamic. I'm still quite sure I can detect a 7-lbs mass change when
climbing out of the saddle on a 10% slope.

As for numbers for me, plug in 130 lbs and north of 300 W.

However, I will concede the following: if somehow you could eliminate the
"micro" accelerations (side-to-side and pedal-stroke-periodic axial) and
truly represent steady-state power output on a climb, then I agree with you
that the *sensation* of the speed difference would not be detectable. All
you would have to go by would be the passing of scenery, road surface, etc.

Mark
http://marcofanelli.blogspot.com

Dear Mark,

I think that we're on the same page. It's a pleasure to reply to
someone so reasonable.

Yes, as you and others point out, you can heave the lighter bike back
and forth or side to side (or up and down, if the hill is steep enough
that the front wheel comes up).

When I strapped 7 pounds of steel rods onto my top tube, I could
easily notice the difference when I heaved my bike up onto its back
wheel to roll it out of the crowded garage. Adding 7 pounds to ~27
pounds is about a 25% increase.

But, as we agree, the rider isn't likely to perceive the finish line
approaching only 4% faster with no reference rider or instruments.

(If I _had_ "noticed" a 4% speed reduction, I would have been dead
wrong--real life turns out to have some confounding factors.)

All the extra thrashing that we might notice can't move the center of
mass up the hill anything more than 4% faster (less in the real world,
where tire and wind drag reduce the effect).

And that's what started all this, a long time ago in another thread.

An article announced that switching from a 21-lb 10-year-old aluminum
bike to a $8500 14-lb 2008 carbon model produced a "noticeably robust
forward thrust" and made cruising speed "easy".

It only works if the rider is fooled by the way that the bike tips and
heaves underneath him. Otherwise, the "thrust" is reduced to an
awfully hard to notice ~4%.

Since 3,000 pound cars don't heave like bicycles, we don't notice the
~4% better acceleration when we drop off a 120 pound passenger and
therefore aren't fooled into thinking that a divorce would really save
on gas money.

***

So let's plug in your 130 pounds and north of 300 watts:
http://bikecalculator.com/veloUS.html

Let's try hoods, tubulars, 130 pound rider, 350 watts, and 14
versus 21 pounds up your 2.9 mile 7.84% hill.

1200/(2.9 * 5280) = 1200/15,312 feet = 7.84% grade

I get 12.43 mph versus 12.01 mph and 14.00 minutes versus 14.49
minutes.

That's 0.49 minutes, a penalty of ~30 seconds in ~14 minutes.

The heavy bike is 14.00/14.49 (96.6%) as fast as the lighter bike.

A 2.15 mph headwind (less than a bystander can feel on his cheek) will
slow the 14 lb bike down to the same 14.49 minute time as adding 7
pounds.

Cheers,

Carl Fogel

On Thu, 17 Jul 2008 09:47:50 -0700 (PDT), Dan O
wrote:

On Jul 17, 1:47 am, wrote:
On Wed, 16 Jul 2008 19:00:39 -0700, "Off The Back"



wrote:
carl fogel wrote:
snip
Consider how trivial adding 7 pounds to the total weight is, compared
to the other factors that produced a 3 minute variation in 7
consecutive daily ride of ~46-49 minutes on 15.1 mile loop with a
400-foot climb. snip

That's not much of a climb over 15 miles, and I certainly agree with your
point that the impact of bike mass is not very significant for steady-state
riding on mostly flat terrain, compared to other factors. But...

...I regularly ride a 1,200 ft climb (2.9 miles long) and am pretty
confident that I could detect the *effect* of a 7-lb difference in my bike.
And I'm positive I could detect the mass difference because of the change in
the bike's characteristics moving side-to-side and fore-and-aft beneath me.
I'd put money on it.

Mark
http://marcofanelli.blogspot.com

Dear Mark,

Hang on to your money.

:-)

Again, the original question was whether a rider could detect a
"noticeably robust forward thrust" with a bike 7 pounds lighter.

Not side-to-side tipping, not handling, not how it feels when hefted
or rolled forward while walking next to it, not how it vibrates, but
how it _accelerates_.

F = M * A or F/M = A

Given a constant power (and no wind or tire drag), the acceleration
changes as the reciprocal of the mass.

In other words, if you weigh 161 pounds and ride a 14 pound bike, the
total mass that you move up _any_ grade of _any_ length is 175 pounds.

Raise the bike's weight by 7 pounds and the 175 pound total increases
all of 4% to 182 pounds.

I agree that what really matters is the total weight that needs to be
moved, and also have disdain for mass-media hyperbole and BS, but
(just playing Devil's advocate for a second here) it seems to me that
you could push on the crank and feel some thrust of the bike sort of
moving forward out from under you a little, which I think does *feel*
different on a lighter bike - not that this is significant to actual
performance.

Dear Dan,

I think that we're on the same page here.

If you stand up, yes, you can probably heave the lighter bike back and
forth more easily, or tip it side to side quicker, or pop the front
wheel off the ground more often on a steep climb.

I think that we agree that the ~4% speed loss up a hill for adding 7
lbs will not be detectable as faster by the rider.

Cheers,

Carl Fogel

Off The Back wrote:
Rather, my cryptic comment was based on the easily-stocked results I found
for Donald--who does indeed race--and since I've also occupied Lantern
Rouge territory, I thought it best not to mention it. Ooops, just did!

In my defense the other half of the field were DNF (and it wasn't due to
designer EPO). Suffice to say a hard climb followed by a turn into a
strong headwind made me all too familiar with the situation I was
trying to explain to foggy Carl, although it probably had more to
do with my Chronic Wattage Deficiency condition than with the weight
of my bike.

Damn and now I've paraded my fatty master excuse which I promised not
to do. Oh well I'm sure Wim Vansevant has an excuse too.