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New Carbon Fiber Information



 
 
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  #11  
Old January 11th 17, 04:28 AM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Default New Carbon Fiber Information

On 1/10/2017 4:11 PM, wrote:
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.

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.


I think you need to draw a free body diagram of the forces involved.


--
- Frank Krygowski
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  #12  
Old January 11th 17, 05:04 AM posted to rec.bicycles.tech
JBeattie
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Default New Carbon Fiber Information

On Tuesday, January 10, 2017 at 7:28:41 PM UTC-8, Frank Krygowski wrote:
On 1/10/2017 4:11 PM, wrote:
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.

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.


I think you need to draw a free body diagram of the forces involved.


Sure, you can pop a wheelie on a steep grade if you put too much weight over the rear wheel on a short wheelbase bike in a super-low gear -- but you can do that with a steel bike, too. That's why you move your weight forward a little -- but not so much that you lose rear traction.

Professional climbers do not use LARGE gears. Post-Lance, they spin. My son was on the crew for the Tour of Utah and was surprised that a lot of domestic and Euro pros were using low gears. Here's a photo that he took:
http://tinyurl.com/hpztj3o That ride has some staggering climbs with 20% grades.

-- Jay Beattie.
  #14  
Old January 11th 17, 08:25 AM posted to rec.bicycles.tech
John B.[_6_]
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Default New Carbon Fiber Information

On Tue, 10 Jan 2017 20:04:55 -0800 (PST), jbeattie
wrote:

On Tuesday, January 10, 2017 at 7:28:41 PM UTC-8, Frank Krygowski wrote:
On 1/10/2017 4:11 PM, wrote:
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.

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.


I think you need to draw a free body diagram of the forces involved.


Sure, you can pop a wheelie on a steep grade if you put too much weight over the rear wheel on a short wheelbase bike in a super-low gear -- but you can do that with a steel bike, too. That's why you move your weight forward a little -- but not so much that you lose rear traction.

Professional climbers do not use LARGE gears. Post-Lance, they spin. My son was on the crew for the Tour of Utah and was surprised that a lot of domestic and Euro pros were using low gears. Here's a photo that he took:
http://tinyurl.com/hpztj3o That ride has some staggering climbs with 20% grades.

-- Jay Beattie.


I would guess that, in spite of what Terrible Tom says, that riders on
the better teams probably use the gears that they know that they need
:-)
--
cheers,

John B.

  #15  
Old January 11th 17, 09:20 AM posted to rec.bicycles.tech
[email protected]
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Posts: 824
Default New Carbon Fiber Information

On Wednesday, January 11, 2017 at 12:06:30 AM UTC+1, 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.


When I go on a trip like that I use a 12-29 cassette which gives me a lowest gear of 34-29. That is enough for me for longer stretches (couple of km) up to 10-12%.


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.


It is the Stelvio looking towards Bormio.

Lou
  #16  
Old January 11th 17, 09:22 AM posted to rec.bicycles.tech
[email protected]
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Posts: 824
Default New Carbon Fiber Information

On Wednesday, January 11, 2017 at 5:04:57 AM UTC+1, jbeattie wrote:
On Tuesday, January 10, 2017 at 7:28:41 PM UTC-8, Frank Krygowski wrote:
On 1/10/2017 4:11 PM, wrote:
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.

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.


I think you need to draw a free body diagram of the forces involved.


Sure, you can pop a wheelie on a steep grade if you put too much weight over the rear wheel on a short wheelbase bike in a super-low gear -- but you can do that with a steel bike, too. That's why you move your weight forward a little -- but not so much that you lose rear traction.

Professional climbers do not use LARGE gears. Post-Lance, they spin. My son was on the crew for the Tour of Utah and was surprised that a lot of domestic and Euro pros were using low gears. Here's a photo that he took:
http://tinyurl.com/hpztj3o That ride has some staggering climbs with 20% grades.

-- Jay Beattie.


Pro riders use 34-28 regurarly on 14% grades and steeper.

Lou
  #19  
Old January 11th 17, 03:16 PM posted to rec.bicycles.tech
AMuzi
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Posts: 13,447
Default New Carbon Fiber Information

On 1/11/2017 1:25 AM, John B. wrote:
On Tue, 10 Jan 2017 20:04:55 -0800 (PST), jbeattie
wrote:

On Tuesday, January 10, 2017 at 7:28:41 PM UTC-8, Frank Krygowski wrote:
On 1/10/2017 4:11 PM, wrote:
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.

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.

I think you need to draw a free body diagram of the forces involved.


Sure, you can pop a wheelie on a steep grade if you put too much weight over the rear wheel on a short wheelbase bike in a super-low gear -- but you can do that with a steel bike, too. That's why you move your weight forward a little -- but not so much that you lose rear traction.

Professional climbers do not use LARGE gears. Post-Lance, they spin. My son was on the crew for the Tour of Utah and was surprised that a lot of domestic and Euro pros were using low gears. Here's a photo that he took:
http://tinyurl.com/hpztj3o That ride has some staggering climbs with 20% grades.

-- Jay Beattie.


I would guess that, in spite of what Terrible Tom says, that riders on
the better teams probably use the gears that they know that they need
:-)


I recall well the wise words of my then-roommate Rich
Hammen, writing in his Competitive Cycling column under the
pseudonym 'Ask Captain America':
Q = Should I train spinning small gears or pushing big gears?
A = To win, you need to spin big gears.

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


  #20  
Old January 11th 17, 04:53 PM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default New Carbon Fiber Information

On Tuesday, January 10, 2017 at 1:11:45 PM UTC-8, 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.

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.

I haven't heard anyone here talking as if they were pro racers so again and again I am wondering what you would do with these super-light and very unreliable bikes. I'm sure you guys are using ultra-low gears to climb with. 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.

FSA carbon cranks - one dealer says that he has had two failures just in his shop
Campy Carbon cranks - three failures in the same shop
Carbon seat posts - the most unreliable part on a carbon bike.
Carbon stems/bar combinations - I have seen these failures myself
Carbon bars - also unreliable
Carbon forks - I have had three of them break. One I spotted before total failure. One permanently injured me. The third just crashed me in a high speed downhill.
Carbon frames - I have point out several cracks in major high end manufacturers to their owners.
Carbon saddles - my brother who is 8" shorter than me and 40 lbs lighter was breaking them every six months but he wanted "the lightest".


What was the failure mode of your CF forks? It sounds like you had serious injuries, and if there were a design or manufacturing defect, you should make a claim -- really.

-- Jay Beattie.
 




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