KEVLAR FORKS

Discussion in 'Cycling Equipment' started by Dorian Smith, Jun 20, 2004.

  1. Dorian Smith

    Dorian Smith Guest

    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.
     
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  2. 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?
     
  3. 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_supermuscle_fork.html

    Carl Fogel
     
  4. jim beam

    jim beam Guest

    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_supermuscle_fork.html
    >
    > Carl Fogel
     
  5. Ian S

    Ian S Guest

    "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.
     
  6. Dorian Smith

    Dorian Smith Guest

    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:[email protected]
    > 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?
     
  7. skuke

    skuke Guest

    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:[email protected]
    >> 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 shit 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
     
  8. winnard

    winnard Guest

    "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
     
  9. Pistof

    Pistof Guest

    "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
     
  10. ZeeExSixAre

    ZeeExSixAre Guest

    "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
     
  11. WooGoogle

    WooGoogle Guest

    > > 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.
     
  12. Werehatrack

    Werehatrack Guest

    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.
     
  13. Dorian Smith

    Dorian Smith Guest

    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
    >
    >
     
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