Are CF frames really safe?

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. ;-)

--
JS

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.

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.

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

note: steel frame

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

On Sun, 28 May 2017 04:29:28 -0700 (PDT), 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.

Lou

Possibly. But I do notice that all of the top tri-athletes are riding
very stiff bikes with almost vertical seat posts and TT bikes are much
the same. Do you think that these bike's were selected for comfort?
--
Cheers,

John B.

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.
--
Cheers,

John B.

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.
--
Cheers,

John B.

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.

--
JS

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.

--
JS

On 29/05/17 13:23, 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.


In addition to this, I just looked up my Easton EC70 road fork, and the
Easton EC70X cyclocross fork. The cyclocross version has additional
bosses for canti brakes, and weighs about 250g more. Not all of that
250g is in the bosses I would guess.

--
JS