Are CF frames really safe?

On Sun, 28 May 2017 07:48:06 -0700 (PDT), wrote:

On Sunday, May 28, 2017 at 2:36:59 AM UTC-7, John B. wrote:
On Sat, 27 May 2017 19:25:36 -0700 (PDT), wrote:

On Saturday, May 27, 2017 at 5:04:06 PM UTC-7, John B. wrote:
On Sat, 27 May 2017 06:25:04 -0700 (PDT), wrote:

On Friday, May 26, 2017 at 7:11:10 PM UTC-7, John B. wrote:
On Fri, 26 May 2017 12:06:16 -0700 (PDT), wrote:

On Friday, May 26, 2017 at 8:30:39 AM UTC-7, jbeattie wrote:

What chart John gave us? Are you talking about the fiberglass boat hull chart?

Damned if I can find it now. But it contained a chart that showed the speed of resin breakdown. You have to remember that this chart was for a very heavy layup. So you have to extrapolate to the MUCH thinner CF bike layup. The long and the short of it is that it appears at least to me as if resins begin breaking down immediately the bike begins being used. This absolutely limits the lifespan of CF bikes whereas aluminum has a fairly long life (though I can't say that I've seen an Al frame break) and steel at 75% or so of max loading has an unlimited fatigue life.

I wish you could find the chart that you mention as to the best of my
recollection I've never posted a chart showing a relationship between
resin breakdown and time.

I believe that you may be referring to the boat hull testing that
showed little or no decrease in composite hull samples taken over a 20
year period.

The chart showed the degradation of resin between a 10 year mark and a 20 year mark. Considering the thickness of the resin which in itself is mechanically sound at that thickness, that alone tells a very complex story.


Again, I'm not sure what you are referring to but if it was the
fiberglass longevity test then here it is again:

Table 1 Physical Property Data for 10 Year and 20 Year Tests of USCG
Patrol Boat.

Tensile Strength average PSI 10 years - 5,990, 20 years - 6,140
10 year, 1 test sample

Compressive Strength average PSI 10 years - 12,200, 20 years - 12,210
10 year, 2 test samples

Flexural Strength average PSI 10 years - 9,410, 20 years - 10,850
10 year,1 test sample

Shear Strength average PSI 10 years - 6,560, 20 years - 6,146
10 year, 3 test samples

Note: the variation on test values may be due to the number of samples
tested. In the 10 year testing from 1 to 3 samples were tested and in
the 20 year test 10 samples were tested.

Well, then that's obviously not where I got the numbers and I'll look around.

Some information I've come across is by makers of polyester resins. They say that the material is not catalyzed in the standard sense but is "initiated" since the initiators are converted mostly to alcohols and eliminated. So polyesters seem to me to be probably somewhat porous. So polyesters also have a very low viscosity of around 6 or so making it very easy to saturate the carbon fiber cloth which looks nothing like the surface woven material that many CF bikes have showing through the clear surface coat. All by itself polyester resin is not very strong and things like buttons are made of it and other "plastic" parts.

Polyester resin is probably the most popular for boat building due to
cost but it isn't what might be called 100% water proof and may absorb
water to some degree and this absorbed water may react with residual
chemicals from the hardener which may result in residual chemicals
that absurd water and contribute to blistering.

Since the mid 1970's nearly all polyester fiberglass hulls are built
with a "barrier coat" which may be an outer layer of cloth which is
applied using a water proof resin such as vinal ester resins, or even
just a single coat of waterproof resin..

Epoxy provides the best water proofing but is substantially more
expensive than other resins. A rough comparison of resin costs is
epoxy costs about twice what polyester does and vinyl esters are
somewhere in the middle.



The makers of epoxy talk about how strong the material is all by itself and long "pot life" - meaning you have a long time to work it. However it has a high viscosity.

Nope. Pot life varies and in addition accelerators are available if
very fast hardening times are necessary. One vendor markets resins
ranging from less then 1 hour to 48 hours pot life.


The giveaway is that you can get epoxy resins in "water clear" so that you can see the reinforcing material. But the clear epoxies have viscosities of over 1200+ - fresh water is 1 I believe.

No that isn't correct. Resins are made in various viscosities. A
fairly light epoxy would have a viscosity of about 500 cps and a
specific gravity about 1.08, water having a specific gravity of 1.0 at
normal room temperature.


With viscosity that high and even if you're using a "slow" setting mixture it would be difficult to both get complete infusion of the carbon fiber material so they must use vacuum methods to ensure complete infusion and elimination of bubbles which are areas of failure.

Now we come to another tricky part: Epoxies are quite flexible and flexing doesn't break them up as I understood from what I've seen. This makes me wonder if they use polyester resins for the main framework and epoxy for the exterior finish.

The strength of hardened epoxy is
Tensile strength 85 N/mm² about 12,419 psi
Flexural strength 112 N/mm² about 16,125 psi

Polyester resins may be 1/4 of that strength.

One man on another group got quite huffy with me when I said that super light construction would lead of rapid failures. He apparently is an engineer with Specialized. But as an example he was using a Tarmac which I believe is a Xcross bike. These aren't in the same arena with the "super lights".

I have been told by several people of average size that they have built bikes weighing in at 12 lbs. The UCI returned my letter asking them to maintain the weight limits. The word from their technical department was that a heavy bike can be weak and a light bike can be strong. Which is like saying Roses are Red.

As I said elsewhere, under the promise of anonymity, a team mechanic on a big time pro team said that they can go through a dozen bikes per rider in a grand tour. Now Pro bikes presently have a weight limit of 16.1 lbs.

Isn't the UCF limit 6.8 kg., or 14.9 lbs. Did they change it?

My brother's Giant racer weighs in exactly that with a "heavy" saddle on it. Let me tell you, when I life it off of the hooks hanging front the ceiling it weighs NOTHING.

I will just have to suffer through my steel bike's horrible weight disadvantage.

The one authoritative source I looked up said that water clear had viscosities between 1200 and 1600 compared to 800 for those that were not water clear.


I don't know about your authoritative sources but resin sellers list
viscosities from as high as 12,000 to as low as 200. Note that SAE 30
oil is about 250.

Also the viscosity of a resin varies tremendously whether it is raw
resin or the resin - hardener mix. One site shows a resin with a
viscosity of 1,000 and the same resin, mixed with the hardener,
viscosity of 350.

looking it up again the weight limit is 6.8 Kg which is 14.99 lbs. The latest Giants are 15 lbs for the TSR's and they are breaking with the apparently reduced QC in order to compete with the Chinese.

Giant is a Chinese (Taiwan) company :-)
--
Cheers,

John B.

On Mon, 29 May 2017 14:24:41 +1000, James
wrote:

On 29/05/17 12:54, John B. wrote:
On Mon, 29 May 2017 07:29:33 +1000, James
wrote:

On 28/05/17 21:50, John B. wrote:
On Sun, 28 May 2017 13:00:49 +1000, James
wrote:

On 27/05/17 23:13, John B. wrote:


But a professional anything wants to win and will work hard to win. If
the choices are a bike that is comfortable and another that goes up
hill like a scalded cat then the comfortable bike gets left behind.


But the differences are not that pronounced.

Probably not but my point was that any real competitor wants to win
and given the choice of a comfortable bike and a bike that is, say 10
minutes faster up "Big Bad Mountain" my guess he will ride the faster
bike.

For a 1 hour long steep climb where wind resistance is negligible, to be
10 minutes faster, the weight of the fast bike + rider would need to be
about 5/6ths the slow.

That would mean somewhere in the vicinity of 10kg weight reduction.

Is that why Froome threw his bike away last year in Le Tour and began to
run, do you think?

Well yes, a 10 minute faster bike is a bit of a stretch but the point
is that you, or any other serious contestant, will take every
advantage that they can and if a bike is faster for a certain race
then I suggest that you will select it over a more comfortable bile.

I knew what the point was. I suggest that when you spend 4-6 hours a
day racing over mountains and such on public roads, comfort isn't
ignored because at the end of the day a rider that feels a bit fresher
by not having been beaten by his bicycle, is more likely to win - all
else being equal. Comfort, to some extent at least, is an advantage.

If you are talking about stage racing I believe that the criteria
might be "the bike that I can finish the race in first place on". In
fact I'd guess that is the overriding criteria for any sports
equipment.
--
Cheers,

John B.

On Mon, 29 May 2017 13:23:40 +1000, James
wrote:

On 29/05/17 08:42, wrote:
On Sunday, May 28, 2017 at 2:23:08 PM UTC-7, James wrote:
On 28/05/17 21:29, wrote:

With the know how of today, you can make a CF bike with which you
can win races and is comfortable.


And the manufacturers _could_ make them durable enough to last a
lifetime.

This is an absolute NO. Pro racing bikes are already getting weight
added to them to meet UCI minimums in anticipation of the weigh limit
being lowered if not entirely eliminated. With these frames and forks
breaking all over the course now, there's absolutely no way these
things could last a lifetime.

You can have weight or strength but not both. And the more "comfort"
meaning the ability to flex, the less reliable the frame and fork
will become.

Do you notice how all of those really strong looking CF frames have
disappeared off of the market? Because like my Time VXR you simply
could not ride them. You could BARELY ride a Colnago Dream Lux or
Reflux which were all aluminum.


I disagree. My very rigid steel frame with CFRP/aluminium forks weighs
~2.2kg.

There is plenty of scope between a sub 1kg frame and fork made from CFRP
and mine to add material for durability. Part of that can come from
extending the rear stays so the back wheel isn't so far under the riders
arse hole, and extending the front of the bike so the front wheel
doesn't cross the riders toes while doing a track stand.

You'll appreciate that a longer beam of the same material and dimensions
flexes more than a short beam under the same load?

The heavier CFRP frame and forks have "disappeared" because of marketing
pressure to sell sub 1kg frame and forks. Let's add a long seat post
and head stem to fit the rider later.

They haven't totally disappeared, Columbus is selling 900 and 1150 gm
frames and forks as heavy as 740 gm, Their lightest fork is 350 gm,
with carbon steerer. The frames come in 6 different sizes.

But, as you say, these parts aren't available in the usual bike shop.

--
Cheers,

John B.

James wrote:
On 29/05/17 12:54, John B. wrote:
On Mon, 29 May 2017 07:29:33 +1000, James
wrote:

On 28/05/17 21:50, John B. wrote:
On Sun, 28 May 2017 13:00:49 +1000, James
wrote:

On 27/05/17 23:13, John B. wrote:


But a professional anything wants to win and will work hard to win. If
the choices are a bike that is comfortable and another that goes up
hill like a scalded cat then the comfortable bike gets left behind.


But the differences are not that pronounced.

Probably not but my point was that any real competitor wants to win
and given the choice of a comfortable bike and a bike that is, say 10
minutes faster up "Big Bad Mountain" my guess he will ride the faster
bike.

For a 1 hour long steep climb where wind resistance is negligible, to be
10 minutes faster, the weight of the fast bike + rider would need to be
about 5/6ths the slow.

That would mean somewhere in the vicinity of 10kg weight reduction.

Is that why Froome threw his bike away last year in Le Tour and began to
run, do you think?

Well yes, a 10 minute faster bike is a bit of a stretch but the point
is that you, or any other serious contestant, will take every
advantage that they can and if a bike is faster for a certain race
then I suggest that you will select it over a more comfortable bile.

I knew what the point was. I suggest that when you spend 4-6 hours a
day racing over mountains and such on public roads, comfort isn't
ignored because at the end of the day a rider that feels a bit fresher
by not having been beaten by his bicycle, is more likely to win - all
else being equal. Comfort, to some extent at least, is an advantage.


My point was that sometime people will buy a 12000 dollar S-Works Venge and
then be unhappy with it because what they really need is a Specialized
Roubaix. The Venge climbs very well but it's a harder ride. I've had the
luxury of borrowing one to do a ride while my bike was in the shop.

I wasn't talking necessarily about the comfort factor though it's there,
but about buying a higher spec'd bike when the difference in specifications
isn't something of which the rider can take advantage. But the Venge is
definitely less comfortable than my Tarmac. Something that probably
speaks more to my conditioning than the bike itself. Which was my other
point.

--
duane

On Sunday, May 28, 2017 at 4:14:00 PM UTC-7, AMuzi wrote:
On 5/28/2017 5:44 PM, wrote:
On Sunday, May 28, 2017 at 3:19:10 PM UTC-7, James wrote:
On 29/05/17 07:51, Frank Krygowski wrote:
On 5/28/2017 5:29 PM, James wrote:
On 28/05/17 21:50, John B. wrote:
On Sun, 28 May 2017 13:00:49 +1000, James
wrote:

On 27/05/17 23:13, John B. wrote:


But a professional anything wants to win and will work hard to win. If
the choices are a bike that is comfortable and another that goes up
hill like a scalded cat then the comfortable bike gets left behind.


But the differences are not that pronounced.

Probably not but my point was that any real competitor wants to win
and given the choice of a comfortable bike and a bike that is, say 10
minutes faster up "Big Bad Mountain" my guess he will ride the faster
bike.

For a 1 hour long steep climb where wind resistance is negligible, to
be 10 minutes faster, the weight of the fast bike + rider would need
to be about 5/6ths the slow.

That would mean somewhere in the vicinity of 10kg weight reduction.

That's next year's model.



Marginal gains of the ceramic pedal bearings. ;-)

The pro mechanic said that they were sending entire frames back to the manufacturer in wheel bags. that is one hell of a lot of fracturing.


Chicago Transit has found a way:
http://www.yellowjersey.org/photosfr...ast/BIACTA.JPG

There was a car at the Indy 500 that was broken into three main pieces yesterday. So your point about this bike obviously being run over means exactly that?

We have already stipulated that if a bike is involved in an accident the material makes little to no difference. The problem is breaking on a normal ride.

BTW - Yesterday I went up to do a short ride on a local hilly road. I got a flat on my new Michelin Pro4 Endurance. It appears to be the size of a goats head thorn but there wasn't anything left to find and any tire gets flats from goats heads.

On Sunday, May 28, 2017 at 7:11:10 PM UTC-7, John B. wrote:
On Sun, 28 May 2017 09:50:45 -0400, Frank Krygowski
wrote:

On 5/28/2017 7:29 AM, wrote:
On Sunday, May 28, 2017 at 5:00:55 AM UTC+2, James wrote:
On 27/05/17 23:13, John B. wrote:


But a professional anything wants to win and will work hard to win. If
the choices are a bike that is comfortable and another that goes up
hill like a scalded cat then the comfortable bike gets left behind.


But the differences are not that pronounced.

--
JS

With the know how of today, you can make a CF bike with which you can win races and is comfortable.

I'd think that in most pro road races, the differences between the best
bike and the worst bike would be negligible.

I suppose in amateur or citizens races the best and worst bikes could be
very much different. But so would the riders. And I'd think it
wouldn't be uncommon that the best rider could win even if he traded
bikes and rode the worst bike.

While it's not road racing, I remember hearing of a guy who occasionally
showed up at a velodrome (in the 1970s) riding a heavy mixte frame just
to prove he could win even on that bike.

Do you think that TT or tri-athlete bikes are ridden just to look
cool? Or is there an advantage there? Based on Chris Boardman's two
one hour records a TT bike is about 7 KM/H faster then a conventional
road racing bike.

Again you aren't making any sense. Most TT's are flat and the rider without a peloton around him is in a perfect aerodynamic tuck. Apples and oranges.

On Sunday, May 28, 2017 at 11:59:06 PM UTC-7, John B. wrote:
On Sun, 28 May 2017 07:48:06 -0700 (PDT), wrote:

On Sunday, May 28, 2017 at 2:36:59 AM UTC-7, John B. wrote:
On Sat, 27 May 2017 19:25:36 -0700 (PDT), wrote:

On Saturday, May 27, 2017 at 5:04:06 PM UTC-7, John B. wrote:
On Sat, 27 May 2017 06:25:04 -0700 (PDT), wrote:

On Friday, May 26, 2017 at 7:11:10 PM UTC-7, John B. wrote:
On Fri, 26 May 2017 12:06:16 -0700 (PDT), wrote:

On Friday, May 26, 2017 at 8:30:39 AM UTC-7, jbeattie wrote:

What chart John gave us? Are you talking about the fiberglass boat hull chart?

Damned if I can find it now. But it contained a chart that showed the speed of resin breakdown. You have to remember that this chart was for a very heavy layup. So you have to extrapolate to the MUCH thinner CF bike layup. The long and the short of it is that it appears at least to me as if resins begin breaking down immediately the bike begins being used. This absolutely limits the lifespan of CF bikes whereas aluminum has a fairly long life (though I can't say that I've seen an Al frame break) and steel at 75% or so of max loading has an unlimited fatigue life.

I wish you could find the chart that you mention as to the best of my
recollection I've never posted a chart showing a relationship between
resin breakdown and time.

I believe that you may be referring to the boat hull testing that
showed little or no decrease in composite hull samples taken over a 20
year period.

The chart showed the degradation of resin between a 10 year mark and a 20 year mark. Considering the thickness of the resin which in itself is mechanically sound at that thickness, that alone tells a very complex story.


Again, I'm not sure what you are referring to but if it was the
fiberglass longevity test then here it is again:

Table 1 Physical Property Data for 10 Year and 20 Year Tests of USCG
Patrol Boat.

Tensile Strength average PSI 10 years - 5,990, 20 years - 6,140
10 year, 1 test sample

Compressive Strength average PSI 10 years - 12,200, 20 years - 12,210
10 year, 2 test samples

Flexural Strength average PSI 10 years - 9,410, 20 years - 10,850
10 year,1 test sample

Shear Strength average PSI 10 years - 6,560, 20 years - 6,146
10 year, 3 test samples

Note: the variation on test values may be due to the number of samples
tested. In the 10 year testing from 1 to 3 samples were tested and in
the 20 year test 10 samples were tested.

Well, then that's obviously not where I got the numbers and I'll look around.

Some information I've come across is by makers of polyester resins. They say that the material is not catalyzed in the standard sense but is "initiated" since the initiators are converted mostly to alcohols and eliminated. So polyesters seem to me to be probably somewhat porous. So polyesters also have a very low viscosity of around 6 or so making it very easy to saturate the carbon fiber cloth which looks nothing like the surface woven material that many CF bikes have showing through the clear surface coat. All by itself polyester resin is not very strong and things like buttons are made of it and other "plastic" parts.

Polyester resin is probably the most popular for boat building due to
cost but it isn't what might be called 100% water proof and may absorb
water to some degree and this absorbed water may react with residual
chemicals from the hardener which may result in residual chemicals
that absurd water and contribute to blistering.

Since the mid 1970's nearly all polyester fiberglass hulls are built
with a "barrier coat" which may be an outer layer of cloth which is
applied using a water proof resin such as vinal ester resins, or even
just a single coat of waterproof resin..

Epoxy provides the best water proofing but is substantially more
expensive than other resins. A rough comparison of resin costs is
epoxy costs about twice what polyester does and vinyl esters are
somewhere in the middle.



The makers of epoxy talk about how strong the material is all by itself and long "pot life" - meaning you have a long time to work it. However it has a high viscosity.

Nope. Pot life varies and in addition accelerators are available if
very fast hardening times are necessary. One vendor markets resins
ranging from less then 1 hour to 48 hours pot life.


The giveaway is that you can get epoxy resins in "water clear" so that you can see the reinforcing material. But the clear epoxies have viscosities of over 1200+ - fresh water is 1 I believe.

No that isn't correct. Resins are made in various viscosities. A
fairly light epoxy would have a viscosity of about 500 cps and a
specific gravity about 1.08, water having a specific gravity of 1.0 at
normal room temperature.


With viscosity that high and even if you're using a "slow" setting mixture it would be difficult to both get complete infusion of the carbon fiber material so they must use vacuum methods to ensure complete infusion and elimination of bubbles which are areas of failure.

Now we come to another tricky part: Epoxies are quite flexible and flexing doesn't break them up as I understood from what I've seen. This makes me wonder if they use polyester resins for the main framework and epoxy for the exterior finish.

The strength of hardened epoxy is
Tensile strength 85 N/mm² about 12,419 psi
Flexural strength 112 N/mm² about 16,125 psi

Polyester resins may be 1/4 of that strength.

One man on another group got quite huffy with me when I said that super light construction would lead of rapid failures. He apparently is an engineer with Specialized. But as an example he was using a Tarmac which I believe is a Xcross bike. These aren't in the same arena with the "super lights".

I have been told by several people of average size that they have built bikes weighing in at 12 lbs. The UCI returned my letter asking them to maintain the weight limits. The word from their technical department was that a heavy bike can be weak and a light bike can be strong. Which is like saying Roses are Red.

As I said elsewhere, under the promise of anonymity, a team mechanic on a big time pro team said that they can go through a dozen bikes per rider in a grand tour. Now Pro bikes presently have a weight limit of 16.1 lbs..

Isn't the UCF limit 6.8 kg., or 14.9 lbs. Did they change it?

My brother's Giant racer weighs in exactly that with a "heavy" saddle on it. Let me tell you, when I life it off of the hooks hanging front the ceiling it weighs NOTHING.

I will just have to suffer through my steel bike's horrible weight disadvantage.

The one authoritative source I looked up said that water clear had viscosities between 1200 and 1600 compared to 800 for those that were not water clear.


I don't know about your authoritative sources but resin sellers list
viscosities from as high as 12,000 to as low as 200. Note that SAE 30
oil is about 250.

Also the viscosity of a resin varies tremendously whether it is raw
resin or the resin - hardener mix. One site shows a resin with a
viscosity of 1,000 and the same resin, mixed with the hardener,
viscosity of 350.

looking it up again the weight limit is 6.8 Kg which is 14.99 lbs. The latest Giants are 15 lbs for the TSR's and they are breaking with the apparently reduced QC in order to compete with the Chinese.

Giant is a Chinese (Taiwan) company :-)

Do you want to argue with the Taiwanese government that they're China?

On Sunday, May 28, 2017 at 9:25:08 PM UTC-7, James wrote:
On 29/05/17 12:54, John B. wrote:
On Mon, 29 May 2017 07:29:33 +1000, James
wrote:

On 28/05/17 21:50, John B. wrote:
On Sun, 28 May 2017 13:00:49 +1000, James
wrote:

On 27/05/17 23:13, John B. wrote:


But a professional anything wants to win and will work hard to win. If
the choices are a bike that is comfortable and another that goes up
hill like a scalded cat then the comfortable bike gets left behind.


But the differences are not that pronounced.

Probably not but my point was that any real competitor wants to win
and given the choice of a comfortable bike and a bike that is, say 10
minutes faster up "Big Bad Mountain" my guess he will ride the faster
bike.

For a 1 hour long steep climb where wind resistance is negligible, to be
10 minutes faster, the weight of the fast bike + rider would need to be
about 5/6ths the slow.

That would mean somewhere in the vicinity of 10kg weight reduction.

Is that why Froome threw his bike away last year in Le Tour and began to
run, do you think?

Well yes, a 10 minute faster bike is a bit of a stretch but the point
is that you, or any other serious contestant, will take every
advantage that they can and if a bike is faster for a certain race
then I suggest that you will select it over a more comfortable bile.

I knew what the point was. I suggest that when you spend 4-6 hours a
day racing over mountains and such on public roads, comfort isn't
ignored because at the end of the day a rider that feels a bit fresher
by not having been beaten by his bicycle, is more likely to win - all
else being equal. Comfort, to some extent at least, is an advantage.

I think John B. is envisioning a TT or aero-bike where rider position is learned and totally uncomfortable for civilians. I've never found a properly fitted racing bike uncomfortable. I've never had a bike that "beat me to death" on ordinary roads when it was properly adjusted, although some of the early clincher tires were like riding on wagon wheels as compared to tubulars. Those days are gone, and I would bet that the best clinchers with latex tubes are pretty close to tubular comfort.

-- Jay Beattie.

On Monday, May 29, 2017 at 8:06:23 AM UTC-7, jbeattie wrote:
On Sunday, May 28, 2017 at 9:25:08 PM UTC-7, James wrote:
On 29/05/17 12:54, John B. wrote:
On Mon, 29 May 2017 07:29:33 +1000, James
wrote:

On 28/05/17 21:50, John B. wrote:
On Sun, 28 May 2017 13:00:49 +1000, James
wrote:

On 27/05/17 23:13, John B. wrote:


But a professional anything wants to win and will work hard to win. If
the choices are a bike that is comfortable and another that goes up
hill like a scalded cat then the comfortable bike gets left behind.


But the differences are not that pronounced.

Probably not but my point was that any real competitor wants to win
and given the choice of a comfortable bike and a bike that is, say 10
minutes faster up "Big Bad Mountain" my guess he will ride the faster
bike.

For a 1 hour long steep climb where wind resistance is negligible, to be
10 minutes faster, the weight of the fast bike + rider would need to be
about 5/6ths the slow.

That would mean somewhere in the vicinity of 10kg weight reduction.

Is that why Froome threw his bike away last year in Le Tour and began to
run, do you think?

Well yes, a 10 minute faster bike is a bit of a stretch but the point
is that you, or any other serious contestant, will take every
advantage that they can and if a bike is faster for a certain race
then I suggest that you will select it over a more comfortable bile.

I knew what the point was. I suggest that when you spend 4-6 hours a
day racing over mountains and such on public roads, comfort isn't
ignored because at the end of the day a rider that feels a bit fresher
by not having been beaten by his bicycle, is more likely to win - all
else being equal. Comfort, to some extent at least, is an advantage.

I think John B. is envisioning a TT or aero-bike where rider position is learned and totally uncomfortable for civilians. I've never found a properly fitted racing bike uncomfortable. I've never had a bike that "beat me to death" on ordinary roads when it was properly adjusted, although some of the early clincher tires were like riding on wagon wheels as compared to tubulars. Those days are gone, and I would bet that the best clinchers with latex tubes are pretty close to tubular comfort.

-- Jay Beattie.

Jay, have you actually ever bought a new high-end carbon bike?

On Monday, May 29, 2017 at 8:18:10 AM UTC-7, wrote:
On Monday, May 29, 2017 at 8:06:23 AM UTC-7, jbeattie wrote:
On Sunday, May 28, 2017 at 9:25:08 PM UTC-7, James wrote:
On 29/05/17 12:54, John B. wrote:
On Mon, 29 May 2017 07:29:33 +1000, James
wrote:

On 28/05/17 21:50, John B. wrote:
On Sun, 28 May 2017 13:00:49 +1000, James
wrote:

On 27/05/17 23:13, John B. wrote:


But a professional anything wants to win and will work hard to win. If
the choices are a bike that is comfortable and another that goes up
hill like a scalded cat then the comfortable bike gets left behind.


But the differences are not that pronounced.

Probably not but my point was that any real competitor wants to win
and given the choice of a comfortable bike and a bike that is, say 10
minutes faster up "Big Bad Mountain" my guess he will ride the faster
bike.

For a 1 hour long steep climb where wind resistance is negligible, to be
10 minutes faster, the weight of the fast bike + rider would need to be
about 5/6ths the slow.

That would mean somewhere in the vicinity of 10kg weight reduction..

Is that why Froome threw his bike away last year in Le Tour and began to
run, do you think?

Well yes, a 10 minute faster bike is a bit of a stretch but the point
is that you, or any other serious contestant, will take every
advantage that they can and if a bike is faster for a certain race
then I suggest that you will select it over a more comfortable bile..

I knew what the point was. I suggest that when you spend 4-6 hours a
day racing over mountains and such on public roads, comfort isn't
ignored because at the end of the day a rider that feels a bit fresher
by not having been beaten by his bicycle, is more likely to win - all
else being equal. Comfort, to some extent at least, is an advantage.

I think John B. is envisioning a TT or aero-bike where rider position is learned and totally uncomfortable for civilians. I've never found a properly fitted racing bike uncomfortable. I've never had a bike that "beat me to death" on ordinary roads when it was properly adjusted, although some of the early clincher tires were like riding on wagon wheels as compared to tubulars. Those days are gone, and I would bet that the best clinchers with latex tubes are pretty close to tubular comfort.

-- Jay Beattie.

Jay, have you actually ever bought a new high-end carbon bike?

Not super-high end because I'm too cheap. My current light bike is a Cannondale SuperSix EVO Red (SRAM Red). I have Dura Ace C35 wheels. Yesterday's ride: https://www.flickr.com/photos/urbana...dx/16505738931 A little rough on a road bike -- but a lot sunnier than that picture. It was nice riding through the shaded fairy kingdom on a hot day. On a humorous note, that road is even worse in some places and it goes though a park called Waterboard Park. You'll confess to anything.

Today's ride if my friend calls back: https://www.youtube.com/watch?v=SSyGGID-YrQ&t=33s

I love my SuperSix. Far more comfortable than my Columbus SL racing bikes of yore, and it tracks better than any bike I've ever owned. I hate double-tap SRAM Red, though -- but that's only because I'm used to STI.

Saturday's ride started with a 45-50mph downhill out of my neighborhood on a road pocked with utility cuts. I was going full blast because I was late for a meet-up. The bike was quiet and like riding on a rail -- far better than my Roubaix, which has less planted front end.


-- Jay Beattie.