Dorian Smith said: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.
