aluminum fat tubes, are they 'butted' also?

On Nov 28, 2:28*am, AMuzi wrote:
James wrote:
On 28/11/11 13:01, AMuzi wrote:
James wrote:
On 28/11/11 12:47, David Scheidt wrote:
wrote:
:On 28/11/11 11:33, Frank Krygowski wrote:
: Lou Holtman wrote:
: On 27 nov, 21:54, wrote:
: On 26/11/11 14:58, Frank Krygowski wrote:
:
:
:
: Can anyone here feel a difference riding a bike with butted
tubes?
:
: Does anyone here have two identical bikes except one has butted
tubes
: where the other has not?
:
: Probably not. But let's talk about benefits. Supposedly, there are
two
: benefits to using butted tubes: Weight reduction, and improved ride.

:How does the ride improve? More flex?

:I thought the purpose was to allow for a strong weld on slightly
thicker
:material, while making the tube lighter overall.

The purpose is to put material where the stresses are higher, and put
less material in the center of the tubes, where it's lower.

What makes the stress higher?

Various jointing methods, typically heating.

Heating may alter the material properties, but not the stress.

http://www.yellowjersey.org/PUCHMP1.JPG

--
Andrew Muzi
* www.yellowjersey.org/
* Open every day since 1 April, 1971

Looks like evidence the lugs had done their work and reduced the
stress levels at the joint but they are plain, not filed lugs so
perhaps they worked too well at their initial job but created
unecessarily high stress at the tube beond them.

On 29/11/11 05:52, Frank Krygowski wrote:
James wrote:
On 28/11/11 12:15, Frank Krygowski wrote:
James wrote:
On 28/11/11 11:33, Frank Krygowski wrote:
Lou Holtman wrote:
On 27 nov, 21:54, wrote:
On 26/11/11 14:58, Frank Krygowski wrote:



Can anyone here feel a difference riding a bike with butted tubes?

Does anyone here have two identical bikes except one has butted
tubes
where the other has not?


(And I notice
nobody has come forward saying they can detect the difference in ride.)

And I notice nobody has come forward with a pair of otherwise identical
bicycles.

Which probably means that there are other ways of achieving whatever
result one expects from butting.

I have no idea how your brain works to come to that conclusion.

I've owned about a dozen bicycles over the years, and no two alike.

Andrew Muzi probably has the best opportunity to test the theory.

IOW, if the marketing guy said "We need
next year's model to be half a pound lighter," the engineer might say
"It's cheaper to supply a different saddle, seatpost and crank than to
go to a butted frame."

And once the lighter components are already installed?

Building a lightweight racing machine is about weight reduction here,
there and elsewhere. Not just in one place at a time. Analysis of a
single component leads to the conclusion you frequently come to, that
the difference is so small, why bother? But analysis of the combined
effect of 20 components leads to the conclusion that most others come
to, that there is a real noticeable difference.

It may be the best chance to find "otherwise identical" bikes occurred
in about 1975 to 1980. Back then, I think, there was less variety of
components, and manufacturers like Raleigh or Peugeot had some frames
with straight gage tubes, some with butted tubes. Perhaps there was
enough feature overlap to get two bikes that were identical, or nearly
so, except for butted tubes.

Still, has anyone got what's needed?

These days, if that marketing guy said "No, the high-zoot saddles are
too expensive, let's change the Chinese-made frame," the engineer would
probably say "Well, we could hydroform the aluminum tubes and save a
little." Butting tubes (which was based on the need to have cylindrical
tubes of constant OD) might not be the most appealing choice.

Anyway, I agree that the proper test for ride quality would be two bikes
that were identical except for the tube butts, and unmarked. These days,
I doubt that test is going to happen.


Indeed.

--
JS.

On Nov 28, 7:43*pm, Peter Cole wrote:
On 11/27/2011 9:24 PM, James wrote:









On 28/11/11 13:01, AMuzi wrote:
James wrote:
On 28/11/11 12:47, David Scheidt wrote:
wrote:
:On 28/11/11 11:33, Frank Krygowski wrote:
: Lou Holtman wrote:
: On 27 nov, 21:54, wrote:
: On 26/11/11 14:58, Frank Krygowski wrote:
:
:
:
: Can anyone here feel a difference riding a bike with butted
tubes?
:
: Does anyone here have two identical bikes except one has butted
tubes
: where the other has not?
:
: Probably not. But let's talk about benefits. Supposedly, there are
two
: benefits to using butted tubes: Weight reduction, and improved ride.

:How does the ride improve? More flex?

:I thought the purpose was to allow for a strong weld on slightly
thicker
:material, while making the tube lighter overall.

The purpose is to put material where the stresses are higher, and put
less material in the center of the tubes, where it's lower.

What makes the stress higher?

Various jointing methods, typically heating.

Heating may alter the material properties, but not the stress.

Welding can leave residual stress.

Luckily most of the twentieth century bicycle frames were brazed steel.

James wrote:
On 29/11/11 05:52, Frank Krygowski wrote:
James wrote:
On 28/11/11 12:15, Frank Krygowski wrote:


(And I notice
nobody has come forward saying they can detect the difference in ride.)

And I notice nobody has come forward with a pair of otherwise identical
bicycles.

Which probably means that there are other ways of achieving whatever
result one expects from butting.

I have no idea how your brain works to come to that conclusion.

Here it is, in more detail for you:

I asked: Can anyone tell by riding whether a bike has butted tubes?
Apparently, you're implying that you can't, unless (perhaps) the bikes
are otherwise identical. That is, any characteristic that butted tubes
might produce can also be produced by other means.

I've owned about a dozen bicycles over the years, and no two alike.

Not surprising.

Andrew Muzi probably has the best opportunity to test the theory.

Perhaps so.

IOW, if the marketing guy said "We need
next year's model to be half a pound lighter," the engineer might say
"It's cheaper to supply a different saddle, seatpost and crank than to
go to a butted frame."

And once the lighter components are already installed?

Already sufficiently described, I think, in my next-to-last paragraph
below. These days there are other options available besides butting
steel tubes.

Building a lightweight racing machine is about weight reduction here,
there and elsewhere. Not just in one place at a time. Analysis of a
single component leads to the conclusion you frequently come to, that
the difference is so small, why bother? But analysis of the combined
effect of 20 components leads to the conclusion that most others come
to, that there is a real noticeable difference.

I've never claimed that changing 20 different components or
characteristics of a bike could not produce a cumulative change that can
be perceived. What I'm skeptical of are the claims I've encountered
that (e.g.) "Since I took two ounces off my freewheel, I can tell my
bike definitely accelerates faster!"

But at the moment, I'm more interested in the specific question of
whether people can tell a butted frame from a straight gage frame by
riding it. Apparently, the answer is no.


It may be the best chance to find "otherwise identical" bikes occurred
in about 1975 to 1980. Back then, I think, there was less variety of
components, and manufacturers like Raleigh or Peugeot had some frames
with straight gage tubes, some with butted tubes. Perhaps there was
enough feature overlap to get two bikes that were identical, or nearly
so, except for butted tubes.

Still, has anyone got what's needed?

These days, if that marketing guy said "No, the high-zoot saddles are
too expensive, let's change the Chinese-made frame," the engineer would
probably say "Well, we could hydroform the aluminum tubes and save a
little." Butting tubes (which was based on the need to have cylindrical
tubes of constant OD) might not be the most appealing choice.

Anyway, I agree that the proper test for ride quality would be two bikes
that were identical except for the tube butts, and unmarked. These days,
I doubt that test is going to happen.


Indeed.



--
- Frank Krygowski

On 29/11/11 08:26, Frank Krygowski wrote:
James wrote:
On 29/11/11 05:52, Frank Krygowski wrote:
James wrote:
On 28/11/11 12:15, Frank Krygowski wrote:


(And I notice
nobody has come forward saying they can detect the difference in
ride.)

And I notice nobody has come forward with a pair of otherwise identical
bicycles.

Which probably means that there are other ways of achieving whatever
result one expects from butting.

I have no idea how your brain works to come to that conclusion.

Here it is, in more detail for you:

I asked: Can anyone tell by riding whether a bike has butted tubes?
Apparently, you're implying that you can't, unless (perhaps) the bikes
are otherwise identical. That is, any characteristic that butted tubes
might produce can also be produced by other means.

I am not implying that. I have no idea whether anyone can tell or not.
I would not like to say either way.

What we expect from butted tubes is a lighter bicycle. Given that the
tube diameter and all else remains the same between two test bicycles,
one can assume the bicycle with butted tubes will not be quite as stiff.

But at the moment, I'm more interested in the specific question of
whether people can tell a butted frame from a straight gage frame by
riding it. Apparently, the answer is no.

More likely, no one knows, because no one has taken the test!

Or have they...

http://forums.roadbikereview.com/3184537-post5.html

--
JS.

On Nov 28, 9:26*pm, Frank Krygowski
wrote:
James wrote:
On 29/11/11 05:52, Frank Krygowski wrote:
James wrote:
On 28/11/11 12:15, Frank Krygowski wrote:

(And I notice
nobody has come forward saying they can detect the difference in ride.)

And I notice nobody has come forward with a pair of otherwise identical
bicycles.

Which probably means that there are other ways of achieving whatever
result one expects from butting.

I have no idea how your brain works to come to that conclusion.

Here it is, in more detail for you:

I asked: Can anyone tell by riding whether a bike has butted tubes?
Apparently, you're implying that you can't, unless (perhaps) the bikes
are otherwise identical. *That is, any characteristic that butted tubes
might produce can also be produced by other means.

I've owned about a dozen bicycles over the years, and no two alike.

Not surprising.

Andrew Muzi probably has the best opportunity to test the theory.

Perhaps so.

IOW, if the marketing guy said "We need
next year's model to be half a pound lighter," the engineer might say
"It's cheaper to supply a different saddle, seatpost and crank than to
go to a butted frame."

And once the lighter components are already installed?

Already sufficiently described, I think, in my next-to-last paragraph
below. *These days there are other options available besides butting
steel tubes.

Building a lightweight racing machine is about weight reduction here,
there and elsewhere. Not just in one place at a time. Analysis of a
single component leads to the conclusion you frequently come to, that
the difference is so small, why bother? But analysis of the combined
effect of 20 components leads to the conclusion that most others come
to, that there is a real noticeable difference.

I've never claimed that changing 20 different components or
characteristics of a bike could not produce a cumulative change that can
be perceived. *What I'm skeptical of are the claims I've encountered
that (e.g.) "Since I took two ounces off my freewheel, I can tell my
bike definitely accelerates faster!"

But at the moment, I'm more interested in the specific question of
whether people can tell a butted frame from a straight gage frame by
riding it. *Apparently, the answer is no.











It may be the best chance to find "otherwise identical" bikes occurred
in about 1975 to 1980. Back then, I think, there was less variety of
components, and manufacturers like Raleigh or Peugeot had some frames
with straight gage tubes, some with butted tubes. Perhaps there was
enough feature overlap to get two bikes that were identical, or nearly
so, except for butted tubes.

Still, has anyone got what's needed?

These days, if that marketing guy said "No, the high-zoot saddles are
too expensive, let's change the Chinese-made frame," the engineer would
probably say "Well, we could hydroform the aluminum tubes and save a
little." Butting tubes (which was based on the need to have cylindrical
tubes of constant OD) might not be the most appealing choice.

Anyway, I agree that the proper test for ride quality would be two bikes
that were identical except for the tube butts, and unmarked. These days,
I doubt that test is going to happen.

Indeed.

--
- Frank Krygowski

Using butted tubes reduces the failure rate. End of story.

On Nov 28, 2:42*pm, James wrote:
On 29/11/11 08:26, Frank Krygowski wrote:


snip


But at the moment, I'm more interested in the specific question of
whether people can tell a butted frame from a straight gage frame by
riding it. Apparently, the answer is no.

More likely, no one knows, because no one has taken the test!

Or have they...

http://forums.roadbikereview.com/3184537-post5.html


Frank's talking about a blind test, I think. Such subjective
impressions are too susceptible to expectations.

James wrote:
On 29/11/11 08:26, Frank Krygowski wrote:

But at the moment, I'm more interested in the specific question of
whether people can tell a butted frame from a straight gage frame by
riding it. Apparently, the answer is no.

More likely, no one knows, because no one has taken the test!

Or have they...

http://forums.roadbikereview.com/3184537-post5.html

To paraphrase: "I did something expensive and complicated to my bike to
see if it would make it better, and by golly I was smart, because it
sure feels better!"

--
- Frank Krygowski

On 29/11/11 12:31, Frank Krygowski wrote:
James wrote:
On 29/11/11 08:26, Frank Krygowski wrote:

But at the moment, I'm more interested in the specific question of
whether people can tell a butted frame from a straight gage frame by
riding it. Apparently, the answer is no.

More likely, no one knows, because no one has taken the test!

Or have they...

http://forums.roadbikereview.com/3184537-post5.html

To paraphrase: "I did something expensive and complicated to my bike to
see if it would make it better, and by golly I was smart, because it
sure feels better!"


To paraphrase: "I don't like to think there might be some detectable
difference in the ride between butted an non butted bicycle frames, so
I'll choose to mock what someone else has done and said in favor of it."

--
JS.

In article
,
Dan O wrote:

On Nov 28, 2:42*pm, James wrote:
On 29/11/11 08:26, Frank Krygowski wrote:


snip


But at the moment, I'm more interested in the specific question of
whether people can tell a butted frame from a straight gage frame by
riding it. Apparently, the answer is no.

More likely, no one knows, because no one has taken the test!

Or have they...

http://forums.roadbikereview.com/3184537-post5.html


Frank's talking about a blind test, I think. Such subjective
impressions are too susceptible to expectations.

Darn unreliable memory. I remember reading a magazine article where
they road tested 6 different bikes, all built with the same geometry and
parts, but made with different tubing. I can't find a web link. Does
this ring a bell with anyone else?