KEVLAR FORKS

Any word on the strength of Kevlar forks? Yesterday I came upon an accident
on a local bike trail. The rider had struck a post and was paralyzed from
the neck down. During the impact, his forks had snapped just below the
brakes. The wheel was still attached. I examined the severed part of the
forks and noted that they were cleanly broken.

Not only did this accident firmly convince me to wear a helmet and ride
safely, but I'm now suspicious of non-metal materials. Should I be? The
rider said the bike was a two-year old Trek with Kevlar forks.

Dorian Smith wrote:
Any word on the strength of Kevlar forks? Yesterday I came upon an accident
on a local bike trail. The rider had struck a post and was paralyzed from
the neck down. During the impact, his forks had snapped just below the
brakes. The wheel was still attached. I examined the severed part of the
forks and noted that they were cleanly broken.

Not only did this accident firmly convince me to wear a helmet and ride
safely, but I'm now suspicious of non-metal materials. Should I be? The
rider said the bike was a two-year old Trek with Kevlar forks.


I've never heard of kevlar forks. Were they carbon?

On Sun, 20 Jun 2004 18:58:49 +0100, Zog The Undeniable
wrote:

Dorian Smith wrote:
Any word on the strength of Kevlar forks? Yesterday I came upon an accident
on a local bike trail. The rider had struck a post and was paralyzed from
the neck down. During the impact, his forks had snapped just below the
brakes. The wheel was still attached. I examined the severed part of the
forks and noted that they were cleanly broken.

Not only did this accident firmly convince me to wear a helmet and ride
safely, but I'm now suspicious of non-metal materials. Should I be? The
rider said the bike was a two-year old Trek with Kevlar forks.


I've never heard of kevlar forks. Were they carbon?

Dear Zog,

The fork in question may not have been Kevlar, but Kevlar
forks undeniably exist:

http://www.hillbrick.com.au/products...scle_fork.html

Carl Fogel

primarily carbon, but with some kevlar fiber to augment the vibration
characteristics. kevlar is not as strong as carbon, but from what i
understand, individual fibers can be less brittle, so you sometimes see
kevlar as "fail safe" where the component can break but not separate.

wrote:
On Sun, 20 Jun 2004 18:58:49 +0100, Zog The Undeniable
wrote:


Dorian Smith wrote:

Any word on the strength of Kevlar forks? Yesterday I came upon an accident
on a local bike trail. The rider had struck a post and was paralyzed from
the neck down. During the impact, his forks had snapped just below the
brakes. The wheel was still attached. I examined the severed part of the
forks and noted that they were cleanly broken.

Not only did this accident firmly convince me to wear a helmet and ride
safely, but I'm now suspicious of non-metal materials. Should I be? The
rider said the bike was a two-year old Trek with Kevlar forks.



I've never heard of kevlar forks. Were they carbon?


Dear Zog,

The fork in question may not have been Kevlar, but Kevlar
forks undeniably exist:

http://www.hillbrick.com.au/products...scle_fork.html

Carl Fogel

"jim beam" wrote in message
...
primarily carbon, but with some kevlar fiber to augment the vibration
characteristics. kevlar is not as strong as carbon, but from what i
understand, individual fibers can be less brittle, so you sometimes see
kevlar as "fail safe" where the component can break but not separate.

It's actually a bit more complicated. Kevlar is actually about as strong in
tension as a high strength carbon fiber and quite a bit stronger than a high
modulus (stiffness) carbon/graphite fiber. Kevlar is however considerably
less stiff which is important in bicycle technology since you will always be
aware of stiffness differenses even if you never come close to the stress
necessary for failure. Kevlar is also poorer in compression which makes
design a bit trickier. It is tougher though which explains why I'd rather
have a Kevlar vest than a carbon fiber one.

The rider said they were Kevlar. The bike looked like a high end model. The
rider said he had ridden 3,500 miles in two years. When I looked at the
break, it appeared to be a fibrous material surrounding an inner metal tube.
I may be wrong about the metal tube. Both forks were sheared almost as
cleanly as if they had been cut with a circular saw.

"Zog The Undeniable" wrote in message
news:40d5d1b5.0@entanet...
Dorian Smith wrote:
Any word on the strength of Kevlar forks? Yesterday I came upon an
accident
on a local bike trail. The rider had struck a post and was paralyzed
from
the neck down. During the impact, his forks had snapped just below the
brakes. The wheel was still attached. I examined the severed part of the
forks and noted that they were cleanly broken.

Not only did this accident firmly convince me to wear a helmet and ride
safely, but I'm now suspicious of non-metal materials. Should I be? The
rider said the bike was a two-year old Trek with Kevlar forks.


I've never heard of kevlar forks. Were they carbon?

On Sun, 20 Jun 2004 15:51:07 -0700, Dorian Smith wrote:

The rider said they were Kevlar. The bike looked like a high end model. The
rider said he had ridden 3,500 miles in two years. When I looked at the
break, it appeared to be a fibrous material surrounding an inner metal tube.
I may be wrong about the metal tube. Both forks were sheared almost as
cleanly as if they had been cut with a circular saw.

"Zog The Undeniable" wrote in message
news:40d5d1b5.0@entanet...
Dorian Smith wrote:
Any word on the strength of Kevlar forks? Yesterday I came upon an
accident
on a local bike trail. The rider had struck a post and was paralyzed
from
the neck down. During the impact, his forks had snapped just below the
brakes. The wheel was still attached. I examined the severed part of the
forks and noted that they were cleanly broken.

Not only did this accident firmly convince me to wear a helmet and ride
safely, but I'm now suspicious of non-metal materials. Should I be? The
rider said the bike was a two-year old Trek with Kevlar forks.


I've never heard of kevlar forks. Were they carbon?



Please correct me if I'm wrong here. Am I to understand that you were
questioning somebody who was just in an accident and paralyzed from the neck
down?? Aren't your priorities a bit screwed up?? And, the guy was willing
to talk to you about his fork?? I would have been freakin' out if I were
unable to move. I wouldn't give a **** about my fork at that moment.

Did the fork break and cause the crash? Or did hitting the post cause the
fork to break? Just confirming here because you said "during the impact."
If it is the second, then that should not alter your decision to ride with
non-metal materials. Hit something hard enough and it would matter what
material the fork was made from.
--
Skuke
Reverse the domain name to send email

"Dorian Smith" wrote in message
...
Any word on the strength of Kevlar forks? Yesterday I came upon an
accident
on a local bike trail. The rider had struck a post and was paralyzed from
the neck down.

Got a local news link?



winnard

"Dorian Smith" wrote in message
...
Any word on the strength of Kevlar forks? Yesterday I came upon an
accident
on a local bike trail. The rider had struck a post and was paralyzed from
the neck down. During the impact, his forks had snapped just below the
brakes. The wheel was still attached. I examined the severed part of the
forks and noted that they were cleanly broken.

Not only did this accident firmly convince me to wear a helmet and ride
safely, but I'm now suspicious of non-metal materials. Should I be? The
rider said the bike was a two-year old Trek with Kevlar forks.

That's horrible. Do you know it he'll be paralyzed for the rest of his
life?

Dave

"Dorian Smith" wrote in message
...
The rider said they were Kevlar. The bike looked like a high end model.
The
rider said he had ridden 3,500 miles in two years. When I looked at the
break, it appeared to be a fibrous material surrounding an inner metal
tube.

Did the fibers have color to them? I believe Kevlar's natural color is
yellow.

--
Phil, Squid-in-Training