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Old 09-29-04, 03:33 PM   #1
cacophony
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carbon fork failure?

I am a bit concerned about a carbon fiber fork failure on my 3 year old Lemond commuter. Especially considering that I weigh around 250 lbs with my bag on, my commute has a lot of hills, and I have an uncanny ability to destroy things. Being a good 50 lbs heavier than "heavy cyclists" makes me concerned that I am especially at risk.

Has anyone had a fork break? Did you live to tell? Where on the fork did the failure happen? I have nightmares about hauling a** down a hill, gettin after the breaks, and the fork snapping off at the bottom of the headtube.

The difference in performance between my carbon and steel forks is very slight. I don't understand why I can't find a new steel fork either. Am I just crazy?
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Old 09-29-04, 04:35 PM   #2
karlfitt
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F1 cars are almost all carbon fiber, and suffer much greater stress than your bike.
I weight 273 and have a carbon fork on my bike too, no worries for me.


Yes there have been forks that have broken (carbon) but I am not the least bit worried about the on on my bike.
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Old 09-29-04, 05:42 PM   #3
SAB
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I am on the opposite end of the spectrum - I weigh about 135lbs. But I do have nearly 40,000 miles in eight years on my carbon fork without problems.
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Old 09-30-04, 11:30 AM   #4
MichaelW
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Carbon F1 cars last only 1 season (if that) and are not used for a daily commute. They can be over-engineered, since its easy to build under the weight limit. Most F1 cars carry about 100kg of ballast just to meet the regulation min weight. When they do crash, they are designed to snap in places, to absorb energy.
The comparison with bike forks is not valid.
Check out
http://www.velonews.com/tech/report/...es/3270.0.html
The main concern seems to be crash damage leading to a deep scratch which acts as a stress raiser.
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Old 09-30-04, 03:03 PM   #5
wrench
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Quote:
Originally Posted by cacophony
I am a bit concerned about a carbon fiber fork failure on my 3 year old Lemond commuter. Especially considering that I weigh around 250 lbs with my bag on, my commute has a lot of hills, and I have an uncanny ability to destroy things. Being a good 50 lbs heavier than "heavy cyclists" makes me concerned that I am especially at risk.

Has anyone had a fork break? Did you live to tell? Where on the fork did the failure happen? I have nightmares about hauling a** down a hill, gettin after the breaks, and the fork snapping off at the bottom of the headtube.

The difference in performance between my carbon and steel forks is very slight. I don't understand why I can't find a new steel fork either. Am I just crazy?
Hi
Worry not. They are well strong, well up to Clydesdale riders. The only probelms we have had in the workshop have been caused by carbon steerer tubes splitting when the wrong kind of star-fangled device is used in aheadsets by customers.
I've been riding Trek OCLV 5500, Lemond Maillot Jeune and Zurich with carbon forks for many years with no problem. In these days of quick litigation, manufacturers do overbuild for strength.
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