Monday, January 19, 2009

26 Safety Moment : Crashing Into Pine Needles


Lets get no illusions about our sport.

It can get dangerous. Losing just a moment's worth of concentration may be enough to unseat you off your saddle smack into danger.

Our second safety moment for the year is Liz Hatch's latest injury report on her blog. As it turns out, she was enjoying the breeze on a fast downhill in a fundraiser ride for the Women's Tour of California Criterium when she approached a corner full of pine needles at more speed than was actually safe. She rode right into the guardrail at 45K and landed face first into the area of needles. Thankfully, she made it but the bike was sheared off at the fork on impact.

If I understand correctly, she was riding one of those monocoque carbon fiber BH bikes. These bikes are said to be reinforced with nanotechnology resins to make them tougher and stronger. Readers will recall how I talked about a very similar failure with BH when a rider in last year's Ghent Wevelgem pro race crashed right into a road decor at full gas. Click here to read.

See More Pics Here

Her facial injuries seem superficial as opposed to deep lacerations but there could be more to the story. As soon as she feels better, I ask her or maybe her friends to give us a brief account of what the doctors did to treat her wounds. I figure that can be beneficial information to anyone reading this.

Does anyone else want to take a shot at how this could have been prevented, or what you can do to think fast and make the right decisions? I feel I'm talking way too much.


UPDATE :

Some comments are really quick. Thanks ensenadajim!


According to her Twits or Tweets or whatever that thing is called, the medical staff had an antibiotic named Neosporin applied to her face to help with the scarring.

Thanks also to Bob Cullinan from Cycleto for these pictures of her wrecked BH bike and her Specialized 2D helmet.

Liz singled out her helmet as saving her head. What's interesting is that in late Dec 2007, these helmets were actually recalled by the CPSC due to failed tests! Click here to read that pollination.


Bam!


* * *

26 comments:

  1. Anonymous7:31 PM

    vanderkitten we love you!! get well soon liz!

    ReplyDelete
  2. No technology will help if you hammer your bike into a road barrier at that speed! Here's wishing Liz a fast recovery.

    ReplyDelete
  3. Brian9:02 PM

    Whats that yellow strand in her helmet?

    ReplyDelete
  4. Brian : I suspect that's the inner kevlar microskeleton of the helmet..like a reinforcing. Don't quote me on it. Just taking a shot.

    ReplyDelete
  5. Anonymous12:17 AM

    Ouch pine needles tsk tsk...

    ReplyDelete
  6. Anonymous12:28 AM

    The mode of failure that occurred on the fork is concerning.
    That is really not the best thing to see.
    - Ryan

    ReplyDelete
  7. From the pictures and report so far it seems like Liz is fortunate. Downhill crashes can have a lot of road rash. Maybe the pine needles were softer of the face and skin than a bare road.

    -Dave Kina

    ReplyDelete
  8. "The mode of failure that occurred on the fork is concerning."

    Um, NO FORK is designed to withstand a barrier hit at 45KPH. I would venture to say that even a steel fork might shear at that speed (or at least be mangled beyond recognition).

    Get well soon, Liz!!

    ReplyDelete
  9. I really don't think the fork failed. It was more like destroyed in a gnarly accident. Nothing was saving it. If she was descending and it shattered while she was cornering that would be a failure.

    Sometimes I think you go a little too far out of the way in order to make jabs at manufactures for issues that really are not their fault.

    I'm glad she's Ok. It could have been much worse

    ReplyDelete
  10. The helmets failed because the buckle was not able to withstand enough force. The only change that was made on the new helmets was they went to the same straps and buckle as the old Decibel.

    And yes that is the kevlar reinforcement in the helmet which appears to have done its job.

    ReplyDelete
  11. Thanks Tyler. Buckle buckle...hmm..gotta work on those buckles.

    ReplyDelete
  12. Anonymous10:43 PM

    Man thats gotta hurt. All I muster right now is "FUCK"!

    ReplyDelete
  13. Anonymous8:15 PM

    Hi Nate & GostRider,
    While I do agree no fork should be expected to survive an impact like the one this fork took, I still feel the manner in which it failed is concerning.

    I would bet that if this fork were shown to a composite engineer from EDGE, Reynolds/MQC, Look, Time, or any other company making an aftermarket brand named fork you could gain a lot of very insightful information that would allow you to better understand my concerns.
    - Ryan

    ReplyDelete
  14. Good call Ryan. Maybe I shouldn't be complacent either. I have seen so many of these types of breakages that now I just wave them off.

    Whats on your mind as far as "concerns" go?

    ReplyDelete
  15. Yeah, let's hear about these concerns...because it looks to me like the fork sheared right at the height of the offending barrier. What else do you think should have happened?!?

    Besides, no amount of engineering, nanotube mumbo-jumbo, differential layering and resin void elimination in the world is going to stop a fork from failing in a high-speed impact like this. Maybe not even a steel fork.

    ReplyDelete
  16. Anonymous3:24 AM

    First, I want to be clear.
    I never stated this fork should have survived this impact.
    Ghostrider, please stop implying I did.

    Now, since we all agree that this fork should be expected to fail when it receives an impact similar to this, we can now think about HOW it should ideally fail.

    Quite simply, I do not know how the bike hit the guardrail.
    Typically, it is not the location midway up the for leg on both sides.

    I do not know how the fork was constructed, but if I were to guess, it was done 'ala a steerer root and fork leg bonding similar to Alpha Q.

    This steerer root would usually end in just about the area of the failure.

    Notice the crown.
    Look how uniform the failure is on the crown.
    The steerer appears to be a 1.125x1.5 model.

    Like I said, I find this failure concerning, but I am not a composite engineer who designers carbon forks.

    Maybe you guys can go contact a mfg and ask them how their fork is designed to fail under impacts such as this?

    That would be super great to post.
    - Ryan

    ReplyDelete
  17. Thanks Ryan.

    There are a number of people here who said that such an impact could break any frame, even if its steel. Some thought has to be given to that statement. Steel can break?

    For a video analysis,
    here's a guy
    trying to break his Steel frame by thrashing it on the ground as hard as he can. Notice that the fork bent, but it DID not break.

    ReplyDelete
  18. Anonymous1:44 AM

    hey, bikes break sometimes but not always. helmets save lives most of the time.. but unfortunately, not always. china, taiwan, the good 'ol usa (and europe!) make bike parts that gotta be recalled sometimes, but thank goodness not always.

    anyone who knows that road knows it deserves some SERIOUS respect...have you all seen/ridden the steep and twisty hairpins (and aren't we in winter when you have to be even more cautious on roads that never see the sun?)

    all this talk of the "bike" and its failure is a mute point.

    this is kind of crash CAN BE AVOIDED. i'm chalking it up to operator error.

    ReplyDelete
  19. Anon : Absolutely. Liz should have been more careful, but like I said, a few minutes worth of concentration loss is enough to get you down on the bitumen.

    ReplyDelete
  20. Anonymous1:16 AM

    Ron, very true.

    ReplyDelete
  21. ".because it looks to me like the fork sheared right at the height of the offending barrier. What else do you think should have happened?!?"

    Ron, I am an engineer as well as a bicycle rider :

    (1) Both sides of the fork have broken at about the same height, which could imply that the breaking forces were equally distributed on both sides.

    (2) The distance between the wheel axis and the breaking point of the fork is less than the radius of the wheels, i.e. it is impossible for the fork to crash directly into the guardrail as it is "protected" by the wheel.

    (3) This is particular true if the front wheel crashed more or less perpendicular into the guard rail [as (1) implies].

    (4) When crashing into the guard rail, the impact was first taken by the front wheel, then transmitted to the end of the fork (where the wheel axis is connected). This caused a strong bending moment in the fork which then failed due to high tensile strength on the front side of the fork (i.e. it didn't sheared off).

    Now my questions:

    If so, why is the front wheel looking more or less intact? It might be buckled or untrue, but this not to a visible degree.

    How can it be that the structural strength of this wheel is so much higher than that of the work? Shouldn't this make as really, really worried about the structural properties of carbon fiber components?

    ReplyDelete
  22. Mob : Thanks for reading. Thats a good point you have there. Hold onto that thought. Will get back to you.

    ReplyDelete
  23. Anonymous9:29 PM

    Maybe it's a good thing the fork sheared instead of transmitting all the force to Miss Hatch's arms, neck and shoulders. Steel may not have sheared in this situation but would likely bend. I've seen a mtn bike's solid steel fork bent back from a steep drop.

    Perhaps a carbon fork could be made so strong it would not break but what would happen to the impact force? Transmitted to the rider? Perhaps to make it stronger would result in greater stiffness that the ride is too harsh or the weight gets too excessive. It's a matter of tradeoff. I doubt the designers had any intention of designing a fork that could survive such a crash.

    ReplyDelete
  24. Anonymous9:57 PM

    Regarding the comment on the front wheel integrity: If you look carefully at the wheel, the portion of it on the ground has two scratches matching the space of the two ridges of the guard rail. It also appears that section of the wheel rim is slightly flattened.

    The wheel will not show similar failure characteristics as the carbon fiber fork. It is an alloy material that has more room for deformation before catastrophic failure. In addition the construction using metal spokes allows further elasticity along the spokes and the nipple threads.

    ReplyDelete

Thank you. I read every single comment.