Another useless gimic?

Ritch <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

[snip]

Quoted message said:

Anyone who wants to pursue the matter will find it easiest to search for colnago and
"high-power" with google, that being the name Colnago uses for this funny-looking frame with a
sort of diamond-cutout spliced into the chain-stay.

Me, I ride a Schwinn.

trialtir-usa.comc40 testing.htmlOpen ↗

[snip]

Quoted message said:

Carl Fogel

I'm not JB, but according to the chart on the c40 page, a 100kg rider will have 5% less vertical
flex = 0.05 * 0.06mm = 0.003mm.

Let me guess... is that worth about 0.0000001psi in the tyre?

Yeah, that's a good point. There are so many other factors involved, how could you possibly notice
such a miniscule difference?
---
DFM

What ever happened to the Colnago dual down tube - the single down tube that split into two when it
reached the bottom bracket ? This seemed to be the "fashion" a few years back with the top end
Colnago frames.

-R

Deep Freud Moors said:

Ritch <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

[snip]

Quoted message said:

Anyone who wants to pursue the matter will find it easiest to search for colnago and
"high-power" with google, that being the name Colnago uses for this funny-looking frame with a
sort of diamond-cutout spliced into the chain-stay.

Me, I ride a Schwinn.

trialtir-usa.comc40 testing.htmlOpen ↗

[snip]

Quoted message said:

Carl Fogel

I'm not JB, but according to the chart on the c40 page, a 100kg rider will have 5% less vertical
flex = 0.05 * 0.06mm = 0.003mm.

Let me guess... is that worth about 0.0000001psi in the tyre?

Yeah, that's a good point. There are so many other factors involved, how could you possibly notice
such a miniscule difference?
---
DFM

No problem. If you have an appropriate saddle of course.

--
Perre

You have to be smarter than a robot to reply.

"David L. Johnson" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

highest mass tested, 100Kg, the new frame flexed not 600 mm, but 600/10000
mm. .06mm. The old frame flexed 580/10000 mm, .058mm That .002mm difference is what they are
advertising.

Well, every little counts.

Where's my credit card?

(Carl Fogel) may have said:

I don't know whether it actually does so or if such stiffness matters, but I was surprised by how
much apparently ignorant scoffing your post generated. You'd think that rec.bicycles.tech posters
would be curious about a weird new frame from a respected manufacturer.

I feel the scoffing is warranted and deserved, based on what Colnago admits in their own posted
information.

The increased vertical flexure in the frame (about which they conveniently failt to mention the
point of measurement, but I'll take it as likely that they are referring to flex at the dropouts)
was .002 mm. Yes, that's right, less than one thousandth of an inch. the alleged decrease in lateral
flex was similar.

I believe they could have measured similar differences between production samples of the old frame.

Bloody useless. It's a gimmick, pure and simple. If they're trying to remain respected, they missed
the mark here.

--
My email address is antispammed; pull WEEDS if replying via e-mail. Yes, I have a killfile. If I
don't respond to something, it's also possible that I'm busy.

Per Elmsäter' may have said:

Deep Freud Moors said:

Ritch <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

[snip]
>
> Anyone who wants to pursue the matter will find it easiest to search for colnago and
> "high-power" with google, that being the name Colnago uses for this funny-looking frame with a
> sort of diamond-cutout spliced into the chain-stay.
>
> Me, I ride a Schwinn.
>
> trialtir-usa.comc40 testing.htmlOpen ↗
>
[snip]
>
> Carl Fogel

I'm not JB, but according to the chart on the c40 page, a 100kg rider will have 5% less vertical
flex = 0.05 * 0.06mm = 0.003mm.

Let me guess... is that worth about 0.0000001psi in the tyre?

Yeah, that's a good point. There are so many other factors involved, how could you possibly
notice such a miniscule difference?
---
DFM

No problem. If you have an appropriate saddle of course.

Perhaps one of Sheldon Brown's special granite ones...

--
My email address is antispammed; pull WEEDS if replying via e-mail. Yes, I have a killfile. If I
don't respond to something, it's also possible that I'm busy.

(Chalo) said:

(Alan Walker) said:

Saw a very expensive frame in my local bicycle shop with large diamond-shaped holes in the
chainstays. The carbon fibre tubes split into two, then rejoined, leaving a hole.

That's what happens when bike buyers let silly people make their bikes out of plastic. (They could
have shaped the frame like a carousel horse instead, but that would have been interesting, so of
course they didn't.)

It's much more difficult to include such ugly and worthless contrivances when the maker is
constrained to a proper material.

Bicycle makers should be "constrained" to "proper materials" about as much as cyclists should be
mandated to wear helmets.

The market will support or kill materials, gimmicks, and designs on it's own, without any artificial
constraint.

Quoted message said:

Chalo Colina

--
Rick Onanian

Simon Brooke said:

Quoted message said:

600/10000 mm. .06mm. The old frame flexed 580/10000 mm, .058mm That .002mm difference is what
they are advertising.

It's a very small amount.

I am amazed that that University lab would permit their name to be used. Such a miniscule difference
is probably well under the expected variation between two frames of the same type. I do like the
purposely misleading scales on the charts, though. That's one for the books. Do you wonder why they
had it arranged to be in mm x 10e4 (the measurement in mm was multiplied by 10000)? That gave
numbers in the hundreds. Would not mm x 10e2 be just as informative, giving numbers in the single
digits? No, since numbers in the hundreds look more significant.

Yes, a small difference may be significant. But this is very, very small, especially for a distance,
chainstay length, of hundreds of mm. Probably beyond the measurement accuracy of their instruments.
The 100kg masses used to produce this deflection are themselves not that accurately determined.
Noise factors such as deflection of the vice holding the frame would easily be as large as this
supposed measurement.

--

David L. Johnson

__o | the people can always be brought to the bidding of the leaders. _`\(,_ | That is easy. All
you have to do is tell them they are being (_)/ (_) | attacked, and denounce the peacemakers for
lack of patriotism and exposing the country to danger. It works the same in any <country. --
Hermann Goering

Quoted message said:

Quoted message said:

It's much more difficult to include such ugly and worthless contrivances when the maker is
constrained to a proper material.

Bicycle makers should be "constrained" to "proper materials" about as much as cyclists should be
mandated to wear helmets.

The market will support or kill materials, gimmicks, and designs on it's own, without any
artificial constraint.

Quoted message said:

Chalo Colina

--
Rick Onanian

Hey Rick, take a chill pill. Nobody was advocating artificially constraining bicycle makers. Chalo
was simply pointing out that if one were constrained to working with the "proper" materials, one
would find it difficult to contrive what Colnago has. This isn't a debate about the free market,
just about silly gimmicks.

Rob Strickland

Werehatrack said:

(Carl Fogel) may have said:

I don't know whether it actually does so or if such stiffness matters, but I was surprised by how
much apparently ignorant scoffing your post generated. You'd think that rec.bicycles.tech posters
would be curious about a weird new frame from a respected manufacturer.

I feel the scoffing is warranted and deserved, based on what Colnago admits in their own posted
information.

Colnago is the champion of silly designs, quite frankly. They've made a reputation on good lugged
steel frames back in the day and on the
C40. Most of their "innovations" are on par with the Hetchins "curly" chain stay or the Bates
"Diadrant" fork: cosmetics but of no real value or significance.

Rick Onanian said:

Bicycle makers should be "constrained" to "proper materials" about as much as cyclists should be
mandated to wear helmets.

The market will support or kill materials, gimmicks, and designs on it's own, without any
artificial constraint.

To an extent, anyway. The trick in the bicycle industry is to serialize such gimmickry so that
people keep buying new bikes with the latest (useless) gimmick. Since Colnago is at the center of
this discussion, let's point to them. They have had a series of gimmicks over the years that last a
year or two and then are quietly shelved in favor of the next gimmick. Ernesto is no fool when it
comes to marketing: style over substance sells more bikes.

[email hidden] (Carl Fogel) wrote in message
news:<[email hidden]>...

[snip]

A follow-up:

What I've seen is more like it!

It sounds as if the engineering crowd is unimpressed with the minuscule increases in horizontal
stiffness claimed by Colnago for their weird new chain-stay design.

But what if we look at it as a 5% (or whatever) reduction in side-to-side thrashing power-loss?

That is, a rider puts out X amount of effort, most of which (I hope) goes into overcoming wind drag,
rolling-resistance, inertia, and broken glass.

But some effort is wasted in all sorts of nooks and crannies, one of which is any side-to-side
flexing of the hideously stiff something-or-other-hedron formed by the seat-tube, chain-stays,
seat-stays, and axle (I read somewhere in another post that there's a name for the geometry and that
the little cross-bar for the brake doesn't count.)

Everyone seems to agree that this side-to-side motion is minute. My question is how much effort is
needed to create that tiny wiggle in such a stiff arrangement of tubing? How much would it help to
reduce this particular loss by 5%?

If half of the overall X effort goes into twisting my rear frame, then it's a 2.5% overall
improvement and worthwhile.

If only 1% of the overall X effort goes into distorting my rear frame, then the potential
improvement is only 0.05% and getting hard to justify.

And is any gain, regardless how large or small, offset by the loss in the claimed greater vertical
flexing that's supposed to make the bike more comfortable?

These are all figures too tricky for me to even guess at, but at least now I know what the question
is--does that bizarre diamond-hole in the chain-stay work to reduce horizontal deflection and
increase vertical deflection, and if so, are the effects large enough to matter?

It may be pure marketing, it may be pure wishful engineering, but I can't say that the ugliness
worries me--where would most of us be if homeliness were grounds for rejection? Even Jobst Brandt
admits that there was a time when he was younger and more beautiful.

Carl Fogel

[email hidden] (Chalo) wrote in message
news:<[email hidden]>...

Quoted message said:

(Alan Walker) said:

Saw a very expensive frame in my local bicycle shop with large diamond-shaped holes in the
chainstays. The carbon fibre tubes split into two, then rejoined, leaving a hole.

That's what happens when bike buyers let silly people make their bikes out of plastic. (They could
have shaped the frame like a carousel horse instead, but that would have been interesting, so of
course they didn't.)

It's much more difficult to include such ugly and worthless contrivances when the maker is
constrained to a proper material.

Chalo Colina

Dear Chalo,

As I remember, you're a machinist and have forgotten more about materials than I'll ever know, so
please gear down for a moment and speak to a layman.

Why is it harder to make these odd frame tubes with their diamond holes out of metal (I assume this
is your proper material) than carbon fiber?

Remember, I'm so ignorant that I don't know whether my ear holes are punched or bored.

(Hope you don't punch me. Doubt I'll be bored.)

Carl Fogel

(Carl Fogel) said:

Dear Chalo,

<snip>

Quoted message said:

Remember, I'm so ignorant that I don't know whether my ear holes are punched or bored.

(Hope you don't punch me. Doubt I'll be bored.)

At his weight, if he's any good at punching, you'd be screwed.

Quoted message said:

Carl Fogel

--
Rick Onanian

"David L. Johnson" <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Carl Fogel said:

Below is a page that explains what advantages the Colnago engineers believe their odd-looking
frame provides, specifically less lateral and vertical flexing.

I don't know whether it actually does so or if such stiffness matters, but I was surprised by
how much apparently ignorant scoffing your post generated. You'd think that rec.bicycles.tech
posters would be curious about a weird new frame from a respected manufacturer.

Well, Colnago has also marketed frames with creased main tubes.

As far as this goes, according to the website you mention:

Quoted message said:

trialtir-usa.comc40 testing.htmlOpen ↗

Indeed has a chart purporting to list the 5% increase in vertical flex. But the scale is
revealing, it gives flex in millimeters X 10e4. At the highest mass tested, 100Kg, the new frame
flexed not 600 mm, but 600/10000
mm. .06mm.

No, according to the chart the new frame flexed 6,000,000 mm. 6 kilometers under a 100 kg load. (The
improvement between old and new frames is left as an exercise...) Now, I realize that your
interpretation is probably closer to what they *meant* to say. But are you going to take seriously
the engineering acumen of a company that can't even get the *sign* of the exponent right in
materials sent out for public consumption? Not to mention that the "load" is measured in units of
mass (kg) instead of force (N).

Carl Fogel said:

But what if we look at it as a 5% (or whatever) reduction in side-to-side thrashing power-loss?

"Stiffness" is a subject that generates a lot of misconceptions, and plain B.S. I reccomend Sheldon
Browns article:

sheldonbrown.comframe materials.htmlOpen ↗

To summarise:
- vertical flex on a bike _frame_ is insignificant, next to tyre and seat flex. Though frame
geometry does affect comfort, frame flex doesnt.
- horizontal flex is greater, but its very elastic, so you dont actually loose significant
energy from it.

Quoted message said:

But some effort is wasted in all sorts of nooks and crannies, one of which is any side-to-side
flexing of the hideously stiff

No, not if the flexing is elastic. Then you get the energy back. Just like a diver or gymnast does
from a springboard.

If you want to see how elastic steel is, try dropping a ball-bearing onto a hard floor. Bounces
quite well, doesnt it? Elasticity is the key here.

Quoted message said:

My question is how much effort is needed to create that tiny wiggle in such a stiff arrangement
of tubing?

Not much, and you get it back on the upstroke.

Quoted message said:

How much would it help to reduce this particular loss by 5%?

No help. Would be easy to do though, by using a larger seat-tube, if it helped.

Quoted message said:

And is any gain, regardless how large or small, offset by the loss in the claimed greater vertical
flexing that's supposed to make the bike more comfortable?

Whoa! Way off. Anyone who claims that might read Sheldon etc. See above.

And BTW, steel vs Al makes no difference to frame flex, as they just adjust the tube size to
compensate for material stiffness & strength.

"David L. Johnson" <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Simon Brooke said:

Quoted message said:

600/10000 mm. .06mm. The old frame flexed 580/10000 mm, .058mm That .002mm difference is what
they are advertising.

It's a very small amount.

I am amazed that that University lab would permit their name to be used. Such a miniscule
difference is probably well under the expected variation between two frames of the same type. I do
like the purposely misleading scales on the charts, though. That's one for the books. Do you
wonder why they had it arranged to be in mm x 10e4 (the measurement in mm was multiplied by
10000)? That gave numbers in the hundreds. Would not mm x 10e2 be just as informative, giving
numbers in the single digits? No, since numbers in the hundreds look more significant.

Yes, a small difference may be significant. But this is very, very small, especially for a
distance, chainstay length, of hundreds of mm. Probably beyond the measurement accuracy of their
instruments. The 100kg masses used to produce this deflection are themselves not that accurately
determined. Noise factors such as deflection of the vice holding the frame would easily be as
large as this supposed measurement.

David L. Johnson

Dear David,

This is the kind of comment that I was hoping for--thanks. If I follow your points, any effects
claimed are likely to be more random variation than the result of the weird frame, all exaggerated
for marketing purposes.

Even a clod like me gets a little suspicious of those graphs, which don't seem to show much
difference.

I do have one timid question.

I have no idea how such tests are performed, but wouldn't it be sensible to duplicate the 100 kg
mass by using the same physical weight on each frame? That is, load the same 100 kg plate from a
barbell onto each frame to guarantee no variation in that parameter, regardless of what the exact
mass happens to be? Or is there an engineering reason for using two weights marked 100 kg that
I'm missing?

Carl Fogel

"David L. Johnson" <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Alan Walker said:

Saw a very expensive frame in my local bicycle shop with large diamond-shaped holes in the
chainstays. The carbon fibre tubes split into two, then rejoined, leaving a hole.

I saw one advertised with an "elastomer insert" stuffed into such a hole. Is this the same bike?
The "elastomer" was kind of transparent.

i havent seen a chainstay elastomer insert, but i think ive seen a few Specialized road bikes with
carbon forks which have holes and what look like big silicone inserts in 'em. i just sighed to
myself, pondered the power of marketing, and patted my surly to let her know i still loved her.

ant said:

Quoted message said:

I saw one advertised with an "elastomer insert" stuffed into such a hole. Is this the same bike?
The "elastomer" was kind of transparent.

i havent seen a chainstay elastomer insert, but i think ive seen a few Specialized road bikes with
carbon forks which have holes and what look like big silicone inserts in 'em.

That's the one. Not what the original thread was about, but what I had seen.

Quoted message said:

i just sighed to myself, pondered the power of marketing, and patted my surly to let her know i
still loved her.

--

David L. Johnson

__o | Become MicroSoft-free forever. Ask me how. _`\(,_ | (_)/ (_) |

Carl Fogel said:

I have no idea how such tests are performed, but wouldn't it be sensible to duplicate the 100 kg
mass by using the same physical weight on each frame? That is, load the same 100 kg plate from a
barbell onto each frame to guarantee no variation in that parameter, regardless of what the exact
mass happens to be? Or is there an engineering reason for using two weights marked 100 kg that I'm
missing?

It would be sensible to do that, yes. On the other hand, a "difference" that is within the
statistical variation of the design is meaningless. A cynic would wonder how many new/old frame
combinations they had to test before they got even that much difference. But the test equipment,
which is usually cobbled together from what is available in the lab, certainly had enough
variability in it itself to nullify any significance of that result. Every time you attach/detach a
frame from the test bed, errors of that size -- we are talking 10^(-7) meters here -- are
inevitable.

--

David L. Johnson

__o | Some people used to claim that, if enough monkeys sat in front _`\(,_ | of enough
typewriters and typed long enough, eventually one of (_)/ (_) | them would reproduce the
collected works of Shakespeare. The internet has proven this not to be the case.