KEVLAR FORKS

[Dorian Smith]

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.

 

[Zog The Undenia]

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?

 

[carlfogel]

On Sun, 20 Jun 2004 18:58:49 +0100, Zog The Undeniable
<[email protected]> 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/products_columbus_supe-
rmuscle_fork.html

Carl Fogel

 

[Jim Beam]

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.

[email protected] wrote:
> On Sun, 20 Jun 2004 18:58:49 +0100, Zog The Undeniable
> <[email protected]> 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/products_columbus_su-
> permuscle_fork.html
>
> Carl Fogel

 

[Ian S]

"jim beam" <[email protected]> wrote in message
news:[email protected]...
> 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.

 

[Dorian Smith]

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" <[email protected]> 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?

 

[Skuke]

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" <[email protected]> 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

 

[Winnard]

"Dorian Smith" <[email protected]> wrote in message
news:[email protected]...
> 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

 

[Pistof]

"Dorian Smith" <[email protected]> wrote in message
news:[email protected]...
> 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

 

[Zeeexsixare]

"Dorian Smith" <[email protected]> wrote in message
news:[email protected]...
> 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

 

[Woogoogle]

> > 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.
> > >
> > >
Where did this occur? I could not find this with a google
news search.

 

[Werehatrack]

On Sun, 20 Jun 2004 10:41:18 -0700, "Dorian Smith"
<[email protected]> 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.

Something about this strikes me very oddly. Several
somethings, in fact.

To address only the technical issue raised: The metal tube
inside the stub of the fork that was still on the bike
doubtless was the metal yoke and mounting tube assembly for
the carbon fiber fork legs. The end of the tubes would be
the logical failure point for such an assembly in an
impact. This does not sound like a Trek fork, however; for
one thing, they make no mention of Kevlar in their
literature. Several other carbon component producers use
Kevlar to reinforce the carbon fiber matrix; such hybrid
composites are actually quite common in the aerospace and
military sectors.

As for the total story...

I find it very odd that a paralysis-inducing incident did
not make it into the local news (print or broadcast) in the
Tacoma area, particularly when such an incident would have
involved a technically challenging extraction from a trail-
riding area.

I find it even more odd that the cyclist involved was
conscious, let alone coherent enough to answer questions
about the bike. I find it quite peculiar that if you were
the first finder of the incident, you were examining the
bike instead of getting help, though I suppose that it's
conceivable that if you were carrying a cell phone and
called 911 from the site, the instructions would have been
to stay put, do nothing, and wait for help to arrive. In
that case, I think I might have been looking at the wreckage
myself. If you weren't the first arriver, I find it odd that
you had access to the bike; the emergency people on the
scene ought to have been keeping anyone with no necessary
skills or equipment well away from the incident.

Many things about this scenario don't add up.

Obligatory helmet observation: You didn't say if the rider
was so equipped. I will not fault those who maintain that
they'd rather leave such a site in a body bag than in
permanent paralysis. They can take their chances their way,
and I'll take mine in the manner I prefer.

Trollometer rating: moderate to high.

 

[Dorian Smith]

The courage of the rider is a second and even more
compelling story. There were about eight riders in his pace
line, nearly all were teenagers (he's
47) who were from a church-related group and training for
the Seattle-to-Portland ride next month. I learned they
were from a church when a co-leader said a prayer over
the prostrate rider. Just before the accident, I was
riding about a quarter mile behind with a young man on
a mountain bike who couldn't keep up with the pace
line. When we reached the accident site, someone had
already called 911. The others were standing around
waiting for the ambulance. At one point two riders
tried to lift the injured rider's head to give him a
drink of water. I suggested they not try to move his
neck. We then sent riders ahead and behind along the
trail to instruct other riders to dismount and walk by
the scene. While we waited, I held up my helmet to
shade him from the sun (temperature was in the 80s --
hot for western Washington). He talked almost
conversationally about the bike and how the accident
happen. All the while he laid on his back with his arms
and legs stretched out and unmoving.

The young men were somewhat stunned and didn't know what to
do or how to act. He talked to them in an unanxious voice,
as if he were trying to help them maintain composure.
Occasionally, he talked about the injury. (That's how I
learned the details.) He was concerned that he couldn't move
his limbs, but once or twice he felt a nudge when someone
touched him. That brought him some comfort.

We probably waited 15-20 minutes before the EMTs arrived. I
then left because there were too many people hanging around
and staring at him. I was irritated by some of the cyclists
who passed by uttering *Poor guy* and *Oh, I'm so sorry.*
and the worst was *Jesus, really?!! He can't move!?* I
remember from First Aid training not to utter pessimistic
comments to help the victim maintain composure.

I've been trying to locate the medical sources to find out
the results of his injury. I hope to find out tomorrow or
the next few days.

He was a very brave man. I'm sure I would have *freaked
out.* But he never lost his composure. A true leader in the
face of tragedy.

On the way home, I mentioned this incident to someone I'd
just met. He recounted one time how he fell 35 feet and was
paralyzed from the neck down for six hours. For the next
couple weeks, he wore a neck brace and suffered an
excruciating burning sensation whenever he was touched.

I hope that the cyclist on the trail that day also is as
lucky and only suffers temporary injuries.

"Pistof" <[email protected]> wrote in message
news:[email protected]...
> "Dorian Smith" <[email protected]> wrote in message
> news:[email protected]...
> > 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