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  #41  
Old January 11th 17, 11:47 PM posted to rec.bicycles.tech
James[_8_]
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Posts: 6,153
Default New Carbon Fiber Information

On 12/01/17 03:30, wrote:
On Tuesday, January 10, 2017 at 5:56:41 PM UTC-8, James wrote:
On 11/01/17 08:11,
wrote:
On Tuesday, January 10, 2017 at 6:48:20 AM UTC-8,
wrote:
A friend who speaks Italian spoke with a bike builder in Italy
who spoke to Ernesto Colnago. He verified that the problem with
Carbon Fiber aside from possible manufacturing defects is that
the resins grow more and more brittle with age. After two years
or so they can grow so brittle that the ultra-lights can fail
at any second. This is why Colnago will only give two year
warranties and why they build their "light" bikes considerably
heavier than other manufacturers.

Have a good ride on your CF when you can get the same weight
with an aluminum frame.

I don't know how many of you besides Joerge make a habit of hard
climbs. But light bikes do NOT make hard climbs much easier. In
fact they add a lot of problems. Once the grade gets up to 18%
you can't use low gears because on the light bikes it will lift
the front wheel off of the ground. The bike will then pivot
around the rear wheel and if you're ready for that you can lay
the bike over before it turns down hill.


That's funny. The difference between a light bike and a "normal"
road bike might be a 1-2kg. Compared to the body weight of the
rider at 70-80kg, this is nothing - and it is a distributed weigh
loss over the entire bike, not just the front end.


James, you are FAR out of it. A "light" bike now is under six kg and
possibly down to 5 1/2.


Not in a UCI sanctioned event it's not. 6.8kg is the lightest.

Experienced cyclists move their body weight forward to keep the
front wheel on the ground and maintain traction with very low
gears. MTB riders have been doing it for decades.


Modern bicycle design with short wheelbases and long top tubes do not
allow you to shift your center of gravity forward unless you can
stand up.


Bull****. They haven't changed the seat post angle of the position of
the seat relative to the crank axle, so you can most certainly slide
forward on the seat regardless of the wheelbase and top tube.

And you can't stand on the pedals on steep hills where you
have to pedal circles.


Sure you can. Drop a couple if cogs and stand up.



The way professional climbers get away with this is that they
use LARGE gears. Then you don't have the leverage to lift the
front wheel.


BS.


George Hincapie won a mountain stage of the Tour even though he is a
sprinter. His gear was a 23 and that was the lowest gear of the group
going over the top.


So what?

--
JS
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  #42  
Old January 12th 17, 12:13 AM posted to rec.bicycles.tech
James[_8_]
external usenet poster
 
Posts: 6,153
Default New Carbon Fiber Information

On 12/01/17 03:36, wrote:
On Tuesday, January 10, 2017 at 5:59:05 PM UTC-8, James wrote:
On 11/01/17 01:48,
wrote:
A friend who speaks Italian spoke with a bike builder in Italy
who spoke to Ernesto Colnago. He verified that the problem with
Carbon Fiber aside from possible manufacturing defects is that
the resins grow more and more brittle with age. After two years
or so they can grow so brittle that the ultra-lights can fail at
any second. This is why Colnago will only give two year
warranties and why they build their "light" bikes considerably
heavier than other manufacturers.

Have a good ride on your CF when you can get the same weight with
an aluminum frame.


I don't believe age is what causes embrittlement in CFRP, but
exposure to UV light and contaminants that may attack the polymer
probably does.


James, you don't HAVE to believe it. All it means is that the curing
agents in the resins have to have a fairly large amount over the
ideal in order to harden in the time necessary to use on a production
line. And since there is more curing agent than resin it will
continue to cure for a VERY long time afterwards. Some chemists
believe that the curing agent is never "used up" but rather is always
present and hence will continue to harden the resin forever. But
experience has shown that after it reaches a certain point the
hardening slows a great deal.

But that SAME experience is showing that this hardening continues
into embrittlement after long enough. There are NO OTHER resins that
offer the characteristics of epoxy or polyesters.

Though you're free to invent a new chemistry.


Actually, if the resin is not fully cross linked during the
manufacturing process, i.e. there are unlinked covalent chemical bonds
as per your posit, that is what can lead to fatigue failure.

https://cyclingtips.com/2015/08/what...-carbon-frame/

But you are free to imagine other worlds where your dreams are reality.

--
JS
  #43  
Old January 12th 17, 12:13 AM posted to rec.bicycles.tech
John B.[_6_]
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Posts: 2,202
Default New Carbon Fiber Information

On Wed, 11 Jan 2017 11:51:44 -0500, Frank Krygowski
wrote:

On 1/11/2017 11:19 AM, wrote:

And eight years ago before my carbon fiber fork failure dumped me on my head I was climbing on steel bikes up 18% grades with a 42-23. Mind you I wasn't fast but I still don't see much sense in that. If you're a racer, fine. But if you aren't trying to go faster than someone else is pure ego.


Sometimes it's not ego; it's training.

FWIW, my "regular" (non-granny) gears are lower than that, and most of
my bikes have triple cranks with "granny" chainrings besides, for use
when absolutely necessary.

But my philosophy has always been to stay out of the little granny ring
during regular riding, no matter how tough the hill. I've always
figured that builds up the quadriceps muscles. And stuff I've read
recently confirmed that the only way to build muscle strength is to
occasionally stress the muscles until they can barely pull one more time.

Anyway, that's what I did in normal riding. Then if I were doing a
super-long ride (over 100 miles), or doing an extended tour especially
with a camping load, I'd use the opposite strategy. I'd drop into as
low a gear as was reasonable at every opportunity. That way I didn't
burn up the reserve of strength I'd built up from the hard pushing.

The combination of those strategies seemed to work for me.


I find it rather revealing that Super Tom charges up big hills (18%)
with what is essentially a 2:1 gearing while the people who race up
My. Washington - average 12% with sections ranging from 18 - 22% -
recommend a 1:1 gearing.

One can only assume that he is much, much, stronger than the
professional hill climbers. (or has a far more vivid imagination)
--
cheers,

John B.

  #44  
Old January 12th 17, 12:19 AM posted to rec.bicycles.tech
Doug Landau
external usenet poster
 
Posts: 1,424
Default New Carbon Fiber Information

On Wednesday, January 11, 2017 at 8:30:13 AM UTC-8, wrote:
On Tuesday, January 10, 2017 at 5:56:41 PM UTC-8, James wrote:
On 11/01/17 08:11, wrote:
On Tuesday, January 10, 2017 at 6:48:20 AM UTC-8,
wrote:
A friend who speaks Italian spoke with a bike builder in Italy who
spoke to Ernesto Colnago. He verified that the problem with Carbon
Fiber aside from possible manufacturing defects is that the resins
grow more and more brittle with age. After two years or so they can
grow so brittle that the ultra-lights can fail at any second. This
is why Colnago will only give two year warranties and why they
build their "light" bikes considerably heavier than other
manufacturers.

Have a good ride on your CF when you can get the same weight with
an aluminum frame.

I don't know how many of you besides Joerge make a habit of hard
climbs. But light bikes do NOT make hard climbs much easier. In fact
they add a lot of problems. Once the grade gets up to 18% you can't
use low gears because on the light bikes it will lift the front wheel
off of the ground. The bike will then pivot around the rear wheel and
if you're ready for that you can lay the bike over before it turns
down hill.


That's funny. The difference between a light bike and a "normal" road
bike might be a 1-2kg. Compared to the body weight of the rider at
70-80kg, this is nothing - and it is a distributed weigh loss over the
entire bike, not just the front end.


James, you are FAR out of it. A "light" bike now is under six kg and possibly down to 5 1/2.

Experienced cyclists move their body weight forward to keep the front
wheel on the ground and maintain traction with very low gears. MTB
riders have been doing it for decades.


Modern bicycle design with short wheelbases and long top tubes do not allow you to shift your center of gravity forward unless you can stand up. And you can't stand on the pedals on steep hills where you have to pedal circles.


The way professional climbers get away with this is that they use
LARGE gears. Then you don't have the leverage to lift the front
wheel.


BS.


George Hincapie won a mountain stage of the Tour even though he is a sprinter. His gear was a 23 and that was the lowest gear of the group going over the top.


Yabbut loookit his legs
  #45  
Old January 12th 17, 12:59 AM posted to rec.bicycles.tech
JBeattie
external usenet poster
 
Posts: 5,870
Default New Carbon Fiber Information

On Tuesday, January 10, 2017 at 3:06:30 PM UTC-8, wrote:
On Tuesday, January 10, 2017 at 2:26:04 PM UTC-8, wrote:
On Tuesday, January 10, 2017 at 9:56:04 PM UTC+1, wrote:
On Tuesday, January 10, 2017 at 11:33:43 AM UTC-8, wrote:
On Tuesday, January 10, 2017 at 3:48:20 PM UTC+1, wrote:
A friend who speaks Italian spoke with a bike builder in Italy who spoke to Ernesto Colnago. He verified that the problem with Carbon Fiber aside from possible manufacturing defects is that the resins grow more and more brittle with age. After two years or so they can grow so brittle that the ultra-lights can fail at any second. This is why Colnago will only give two year warranties and why they build their "light" bikes considerably heavier than other manufacturers.

Have a good ride on your CF when you can get the same weight with an aluminum frame.

Colnago doesn't have the know how to build light CF bikes that last and/or stiff enough so the answer of Ernesto doesn't surprise me.
Something like Kodak that didn't know anything about digital camera's.

Show me an aluminum frame of 850 grams. Any frame lighter than 1300 gram I prefer the CF one. YMMV.

Lou

Lou - what frame of ANY sort weighs a lb and three quarters?


My CF frame (850 gr doesn't include fork). Last 2 seasons I rode this bike

https://picasaweb.google.com/1010765...CPnlxYTUi5_zfA

Best bike I ever had. I replaced the seat post with a Thomson Masterpiece because the CF Ritchey post kept creaking because of a design flaw.

I saw and Eddy Merckx aluminum frame and fork that weighed 4 lbs. On steel bike maker tells me that he is making 16 lb bikes all up.

What would YOU use a 12 lb all up bike for?


Climbing and descending famous mountain passes in Europe for instance this year (a selection):

http://lh3.googleusercontent.com/-zt...o/IMG_1499.JPG

http://lh3.googleusercontent.com/-wP...o/IMG_1493.JPG

http://lh3.googleusercontent.com/-fq...o/IMG_1495.JPG


Lou


What - are you the punk kid of the group? Your bike isn't geared particularly low. These days I'm seeing more and more compacts with a 34 on the back. And I thought my 39-28 was cheating after the 39-25. But I do carry a triple now do that anything over 14% I use the 30-25 or so. But there are VERY few extended climbs over 12% around here.

While the Gavia and the Umbrail aren't particularly high they are known for their difficulty because of the speed of the climbs by the pro peloton.

The first one I recognize but can't place it.

The death ride is about the same sort of riding and the roads are a whole lot better. It has a total climb of around 50,000 ft. But it isn't much fun. You have people flying by you only to be laying on the ground trying to catch their breath 5 miles further on. Somewhere or another I went over a pass that was over 10,000 ft. That's when the air REALLY gets thin.


Tom, are you talking about the Markleeville Death Ride? The standard version is about 15,000-16,000 feet of climbing. I did the six pass "Death Ride the 13th" that was closer to 19,000 (it included Pacific Grade and the back side of Ebbets Pass and Luther Pass), but that was a one-off deal. Ebbetts is under 9,000 feet. https://deathride.com/wp-content/upl...1/elemaplg.jpg But 9,000 is high enough if you're coming from sea level. Tioga is the highest pass in California at 9940 feet, but it's not on the Death Ride.

The old Death Ride was more interesting -- Monitor/Monitor, Ebbetts, Luther and Carson. I think they dumped Luther because its the route to Lake Tahoe, and the tourists and locals probably didn't appreciate having the road shut down all day.

-- Jay Beattie.
  #46  
Old January 12th 17, 04:20 AM posted to rec.bicycles.tech
[email protected]
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Posts: 3,345
Default New Carbon Fiber Information

On Wednesday, January 11, 2017 at 11:48:02 AM UTC-8, jbeattie wrote:
On Wednesday, January 11, 2017 at 11:27:12 AM UTC-8, wrote:
On Tuesday, January 10, 2017 at 3:11:45 PM UTC-6, wrote:

I'm not that good of a climber but I can run down most of the best around here if I'm in the mood. I can even give them a quarter mile lead on a hard climb.


You must be a retired professional rider. Or you live where every rider is extremely obese. Or like to make things up and live in a fantasy world.


No offense, but at 72, any young Cat 5 who couldn't beat him should take up another sport -- like darts. Among his age peers, however, he might be superman.


Yeah, that's it - I'm talking about outriding LeMond in his heyday.
  #48  
Old January 12th 17, 04:58 AM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,345
Default New Carbon Fiber Information

On Wednesday, January 11, 2017 at 4:59:26 PM UTC-8, jbeattie wrote:
On Tuesday, January 10, 2017 at 3:06:30 PM UTC-8, wrote:
On Tuesday, January 10, 2017 at 2:26:04 PM UTC-8, wrote:
On Tuesday, January 10, 2017 at 9:56:04 PM UTC+1, wrote:
On Tuesday, January 10, 2017 at 11:33:43 AM UTC-8, wrote:
On Tuesday, January 10, 2017 at 3:48:20 PM UTC+1, wrote:
A friend who speaks Italian spoke with a bike builder in Italy who spoke to Ernesto Colnago. He verified that the problem with Carbon Fiber aside from possible manufacturing defects is that the resins grow more and more brittle with age. After two years or so they can grow so brittle that the ultra-lights can fail at any second. This is why Colnago will only give two year warranties and why they build their "light" bikes considerably heavier than other manufacturers.

Have a good ride on your CF when you can get the same weight with an aluminum frame.

Colnago doesn't have the know how to build light CF bikes that last and/or stiff enough so the answer of Ernesto doesn't surprise me.
Something like Kodak that didn't know anything about digital camera's.

Show me an aluminum frame of 850 grams. Any frame lighter than 1300 gram I prefer the CF one. YMMV.

Lou

Lou - what frame of ANY sort weighs a lb and three quarters?

My CF frame (850 gr doesn't include fork). Last 2 seasons I rode this bike

https://picasaweb.google.com/1010765...CPnlxYTUi5_zfA

Best bike I ever had. I replaced the seat post with a Thomson Masterpiece because the CF Ritchey post kept creaking because of a design flaw.

I saw and Eddy Merckx aluminum frame and fork that weighed 4 lbs. On steel bike maker tells me that he is making 16 lb bikes all up.

What would YOU use a 12 lb all up bike for?

Climbing and descending famous mountain passes in Europe for instance this year (a selection):

http://lh3.googleusercontent.com/-zt...o/IMG_1499.JPG

http://lh3.googleusercontent.com/-wP...o/IMG_1493.JPG

http://lh3.googleusercontent.com/-fq...o/IMG_1495.JPG


Lou


What - are you the punk kid of the group? Your bike isn't geared particularly low. These days I'm seeing more and more compacts with a 34 on the back. And I thought my 39-28 was cheating after the 39-25. But I do carry a triple now do that anything over 14% I use the 30-25 or so. But there are VERY few extended climbs over 12% around here.

While the Gavia and the Umbrail aren't particularly high they are known for their difficulty because of the speed of the climbs by the pro peloton..

The first one I recognize but can't place it.

The death ride is about the same sort of riding and the roads are a whole lot better. It has a total climb of around 50,000 ft. But it isn't much fun. You have people flying by you only to be laying on the ground trying to catch their breath 5 miles further on. Somewhere or another I went over a pass that was over 10,000 ft. That's when the air REALLY gets thin.


Tom, are you talking about the Markleeville Death Ride? The standard version is about 15,000-16,000 feet of climbing. I did the six pass "Death Ride the 13th" that was closer to 19,000 (it included Pacific Grade and the back side of Ebbets Pass and Luther Pass), but that was a one-off deal. Ebbetts is under 9,000 feet. https://deathride.com/wp-content/upl...1/elemaplg.jpg But 9,000 is high enough if you're coming from sea level. Tioga is the highest pass in California at 9940 feet, but it's not on the Death Ride.

The old Death Ride was more interesting -- Monitor/Monitor, Ebbetts, Luther and Carson. I think they dumped Luther because its the route to Lake Tahoe, and the tourists and locals probably didn't appreciate having the road shut down all day.

-- Jay Beattie.


Jesus Jay, you caught me in a typo.
 




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