Niterider + cannondale carbon fork = crash

[Michael]

Hi All,

Along the lines of the squirrel in wheel/ carbon fork debate, I'm
curious to hear whether people here think that the component failure I
experienced in an accident was within the range of "normal carbon
behavior", and whether anyone here has heard of something similar,
either with the fork or with the light.

I was crossing an intersection at a relatively slow speed - sub 10mph
- when my niterider light detached from the handlebars and swung into
my front wheel, causing the cannondale carbon fork to shear off. I
hit the ground face first and was knocked out on impact.

The problem seems to have been caused by the plastic release lever on
the light, which is supposed to act as a stop when engaged in the
depression of the mount. The lever on mine doesn't seem to
effectively stop the light from sliding back out of the mount.
Although it snaps into place, it still slides back out with minimal
effort - ie without having to depress the lever. The bumps and
vibration of normal road riding seem to have been enough to work the
light out of the mount. Unfortunately, the light is heavy enough that
it pulled right through the velcro straps and swung into my front
wheel.

Anyone ever heard of something like this happening before? Thoughts
on how the fork reacted at such a slow speed?

I appreciate any feedback-

 

[Larry]

On Fri, 20 Jun 2008 17:23:16 -0700 (PDT), Michael <[email protected]>
wrote:

>Hi All,
>
>Along the lines of the squirrel in wheel/ carbon fork debate, I'm
>curious to hear whether people here think that the component failure I
>experienced in an accident was within the range of "normal carbon
>behavior", and whether anyone here has heard of something similar,
>either with the fork or with the light.
>
>I was crossing an intersection at a relatively slow speed - sub 10mph
>- when my niterider light detached from the handlebars and swung into
>my front wheel, causing the cannondale carbon fork to shear off. I
>hit the ground face first and was knocked out on impact.
>
>The problem seems to have been caused by the plastic release lever on
>the light, which is supposed to act as a stop when engaged in the
>depression of the mount. The lever on mine doesn't seem to
>effectively stop the light from sliding back out of the mount.
>Although it snaps into place, it still slides back out with minimal
>effort - ie without having to depress the lever. The bumps and
>vibration of normal road riding seem to have been enough to work the
>light out of the mount. Unfortunately, the light is heavy enough that
>it pulled right through the velcro straps and swung into my front
>wheel.
>
>Anyone ever heard of something like this happening before? Thoughts
>on how the fork reacted at such a slow speed?
>
>I appreciate any feedback-
>
>

I used to commute to the train station in the dark and used a
Niterider lighting system. I had problems with the lamp head
frequently pulling out of the mount. When I contacte Niterider I was
advised to route the cable in such a manner that the lamp head was
pulled forward by the weight of the cable, not back. Never had a
problem after that.

Larry

--

When trying to contact me, be polite. Rudeness will not get you anywhere.

Larry

 

[Werehatrack]

On Fri, 20 Jun 2008 17:23:16 -0700 (PDT), Michael <[email protected]>
may have said:

>Hi All,
>
>Along the lines of the squirrel in wheel/ carbon fork debate, I'm
>curious to hear whether people here think that the component failure I
>experienced in an accident was within the range of "normal carbon
>behavior", and whether anyone here has heard of something similar,
>either with the fork or with the light.
>
>I was crossing an intersection at a relatively slow speed - sub 10mph
>- when my niterider light detached from the handlebars and swung into
>my front wheel, causing the cannondale carbon fork to shear off. I
>hit the ground face first and was knocked out on impact.
>
>The problem seems to have been caused by the plastic release lever on
>the light, which is supposed to act as a stop when engaged in the
>depression of the mount. The lever on mine doesn't seem to
>effectively stop the light from sliding back out of the mount.
>Although it snaps into place, it still slides back out with minimal
>effort - ie without having to depress the lever. The bumps and
>vibration of normal road riding seem to have been enough to work the
>light out of the mount. Unfortunately, the light is heavy enough that
>it pulled right through the velcro straps and swung into my front
>wheel.
>
>Anyone ever heard of something like this happening before? Thoughts
>on how the fork reacted at such a slow speed?
>
>I appreciate any feedback-

My recollection is that the Niterider always has an external battery
pack, but I have yet to own one. Does the cable have a quick
disconnect at the light head? If so, I'd have thought that the
instructions would have advised securing the cable to the handlebars
near the mount, in which case the light likely wouldn't have been able
to swing into the wheel. In a quick look at one of their instruction
sheets online, there wasn't much explicitly mentioned about securing
the cable.

Any reasonably stout and sufficiently large object which gets into the
spokes and comes up to the fork will suddenly stop the wheel at that
point. Usually, the wheel will not break traction with the pavement
(I've had this happen to me just twice in the past 40 years, and
neither time did the wheel skid). A steel or aluminum fork will
likely bend rather than shearing under the load, but I would fully
expect just about any carbon fork to fail completely. Most carbon
fiber construction is engineered to have all of its forces applied in
certain directions and from certain places on the structure; random
substantial forces in unexpected locations can easily distort the
structure enough to take it outside its design limits, and one
potential result is breakage.

I can't say if the design of the Niteriders has an inherent gotcha in
this area. If the cable is long enough to permit the light to fall
into the spokes, I'd expect there to be a provision for securing the
cable to the bars next to the light head, just as a method of making
sure that the light can't fall very far if it comes loose. If the
light head has a non-detachable pigtail, this might not be practical
or effective.

Either way, I doubt that the described failure occurs very often.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

 

[[email protected]]

On Jun 20, 8:23 pm, Michael <[email protected]> wrote:
> Hi All,
>
> Along the lines of the squirrel in wheel/ carbon fork debate, I'm
> curious to hear whether people here think that the component failure I
> experienced in an accident was within the range of "normal carbon
> behavior", and whether anyone here has heard of something similar,
> either with the fork or with the light.
>
> I was crossing an intersection at a relatively slow speed - sub 10mph
> - when my niterider light detached from the handlebars and swung into
> my front wheel, causing the cannondale carbon fork to shear off.  I
> hit the ground face first and was knocked out on impact.
>
> The problem seems to have been caused by the plastic release lever on
> the light, which is supposed to act as a stop when engaged in the
> depression of the mount.  The lever on mine doesn't seem to
> effectively stop the light from sliding back out of the mount.
> Although it snaps into place, it still slides back out with minimal
> effort - ie without having to depress the lever.  The bumps and
> vibration of normal road riding seem to have been enough to work the
> light out of the mount.  Unfortunately, the light is heavy enough that
> it pulled right through the velcro straps and swung into my front
> wheel.
>
> Anyone ever heard of something like this happening before?   Thoughts
> on how the fork reacted at such a slow speed?
>
> I appreciate any feedback-

sounds like a design deficiency with the light; you really should
contact a lawyer, find a good one from a good firm and see what advice
he could provide

 

[[email protected]]

Ge t a new bike and medical bills paid


On Jun 21, 12:51 am, [email protected] wrote:
> On Jun 20, 8:23 pm, Michael <[email protected]> wrote:
>
>
>
>
>
> > Hi All,
>
> > Along the lines of the squirrel in wheel/ carbon fork debate, I'm
> > curious to hear whether people here think that the component failure I
> > experienced in an accident was within the range of "normal carbon
> > behavior", and whether anyone here has heard of something similar,
> > either with the fork or with the light.
>
> > I was crossing an intersection at a relatively slow speed - sub 10mph
> > - when my niterider light detached from the handlebars and swung into
> > my front wheel, causing the cannondale carbon fork to shear off.  I
> > hit the ground face first and was knocked out on impact.
>
> > The problem seems to have been caused by the plastic release lever on
> > the light, which is supposed to act as a stop when engaged in the
> > depression of the mount.  The lever on mine doesn't seem to
> > effectively stop the light from sliding back out of the mount.
> > Although it snaps into place, it still slides back out with minimal
> > effort - ie without having to depress the lever.  The bumps and
> > vibration of normal road riding seem to have been enough to work the
> > light out of the mount.  Unfortunately, the light is heavy enough that
> > it pulled right through the velcro straps and swung into my front
> > wheel.
>
> > Anyone ever heard of something like this happening before?   Thoughts
> > on how the fork reacted at such a slow speed?
>
> > I appreciate any feedback-
>
> sounds like a design deficiency with the light; you really should
> contact a lawyer, find a good one from a good firm and see what advice
> he could provide- Hide quoted text -
>
> - Show quoted text -

 

[A Muzi]

Michael wrote:
> Along the lines of the squirrel in wheel/ carbon fork debate, I'm
> curious to hear whether people here think that the component failure I
> experienced in an accident was within the range of "normal carbon
> behavior", and whether anyone here has heard of something similar,
> either with the fork or with the light.
> I was crossing an intersection at a relatively slow speed - sub 10mph
> - when my niterider light detached from the handlebars and swung into
> my front wheel, causing the cannondale carbon fork to shear off. I
> hit the ground face first and was knocked out on impact.
> The problem seems to have been caused by the plastic release lever on
> the light, which is supposed to act as a stop when engaged in the
> depression of the mount. The lever on mine doesn't seem to
> effectively stop the light from sliding back out of the mount.
> Although it snaps into place, it still slides back out with minimal
> effort - ie without having to depress the lever. The bumps and
> vibration of normal road riding seem to have been enough to work the
> light out of the mount. Unfortunately, the light is heavy enough that
> it pulled right through the velcro straps and swung into my front
> wheel.
> Anyone ever heard of something like this happening before? Thoughts
> on how the fork reacted at such a slow speed?
> I appreciate any feedback-

As another writer noted, the fork failure dissipated some of the energy,
which is good. It is not unusual to wreck a fork, or even wrap up a stay:
http://www.yellowjersey.org/brnn.html

when objects interfere with a wheel's motion.

Designers didn't make any particular effort against objects in spokes
for steel, carbon, ti or any other material. If they did, you'd merely
launch a bit more more effectively as the heavier-material bike would
decelerate a bit more suddenly.
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **

 

[jim beam]

A Muzi wrote:
> Michael wrote:
>> Along the lines of the squirrel in wheel/ carbon fork debate, I'm
>> curious to hear whether people here think that the component failure I
>> experienced in an accident was within the range of "normal carbon
>> behavior", and whether anyone here has heard of something similar,
>> either with the fork or with the light.
>> I was crossing an intersection at a relatively slow speed - sub 10mph
>> - when my niterider light detached from the handlebars and swung into
>> my front wheel, causing the cannondale carbon fork to shear off. I
>> hit the ground face first and was knocked out on impact.
>> The problem seems to have been caused by the plastic release lever on
>> the light, which is supposed to act as a stop when engaged in the
>> depression of the mount. The lever on mine doesn't seem to
>> effectively stop the light from sliding back out of the mount.
>> Although it snaps into place, it still slides back out with minimal
>> effort - ie without having to depress the lever. The bumps and
>> vibration of normal road riding seem to have been enough to work the
>> light out of the mount. Unfortunately, the light is heavy enough that
>> it pulled right through the velcro straps and swung into my front
>> wheel.
>> Anyone ever heard of something like this happening before? Thoughts
>> on how the fork reacted at such a slow speed?
>> I appreciate any feedback-
>
> As another writer noted, the fork failure dissipated some of the energy,
> which is good. It is not unusual to wreck a fork, or even wrap up a stay:
> http://www.yellowjersey.org/brnn.html

so, http://www.yellowjersey.org/mitch.html, where exactly /do/ you draw
the line?


>
> when objects interfere with a wheel's motion.
>
> Designers didn't make any particular effort against objects in spokes
> for steel, carbon, ti or any other material. If they did, you'd merely
> launch a bit more more effectively as the heavier-material bike would
> decelerate a bit more suddenly.

 

[A Muzi]

>> Michael wrote:
>>> Along the lines of the squirrel in wheel/ carbon fork debate, I'm
>>> curious to hear whether people here think that the component failure I
>>> experienced in an accident was within the range of "normal carbon
>>> behavior", and whether anyone here has heard of something similar,
>>> either with the fork or with the light.
>>> I was crossing an intersection at a relatively slow speed - sub 10mph
>>> - when my niterider light detached from the handlebars and swung into
>>> my front wheel, causing the cannondale carbon fork to shear off. I
>>> hit the ground face first and was knocked out on impact.
>>> The problem seems to have been caused by the plastic release lever on
>>> the light, which is supposed to act as a stop when engaged in the
>>> depression of the mount. The lever on mine doesn't seem to
>>> effectively stop the light from sliding back out of the mount.
>>> Although it snaps into place, it still slides back out with minimal
>>> effort - ie without having to depress the lever. The bumps and
>>> vibration of normal road riding seem to have been enough to work the
>>> light out of the mount. Unfortunately, the light is heavy enough that
>>> it pulled right through the velcro straps and swung into my front
>>> wheel.
>>> Anyone ever heard of something like this happening before? Thoughts
>>> on how the fork reacted at such a slow speed?
>>> I appreciate any feedback-

> A Muzi wrote:
>> As another writer noted, the fork failure dissipated some of the
>> energy, which is good. It is not unusual to wreck a fork, or even wrap
>> up a stay:
>> http://www.yellowjersey.org/brnn.html
>> when objects interfere with a wheel's motion.
>>
>> Designers didn't make any particular effort against objects in spokes
>> for steel, carbon, ti or any other material. If they did, you'd merely
>> launch a bit more more effectively as the heavier-material bike would
>> decelerate a bit more suddenly.

jim beam wrote:
> so, http://www.yellowjersey.org/mitch.html, where exactly /do/ you draw
> the line?

A lot of endeavors just make no sense. I'm full of that criticism
myself, and frequently.

But taken as a series of small challenges for a rider who just can't
bear to replace a more than worn out bike, a lot is actually possible!
--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971
** Posted from http://www.teranews.com **