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broken carbon fork that caused crash

Posted: Sat May 28, 2011 11:10 am
by Lister Farrar
One of the triathlon coaches I help out had a bad fall last weekend.

http://www.youtube.com/watch?v=mSasloVv ... re=related

Please check your forks. This bike is about 10 years old.

Re: broken carbon fork that caused crash

Posted: Sat May 28, 2011 12:00 pm
by Josh.E
did that fail at the interface to the metal steertube? bonding metal to carbon was one of the last things the bike industry managed to figure out how to get right

Re: broken carbon fork that caused crash

Posted: Sat May 28, 2011 12:07 pm
by Lister Farrar
Josh.E wrote:did that fail at the interface to the metal steertube? bonding metal to carbon was one of the last things the bike industry managed to figure out how to get right
Haven't seen it up close, but it looks like the carbon blades came off some kind of alu crown legs.

How long ago did they get that right? Before or after my family's carbon forks were made? (gulp)

Re: broken carbon fork that caused crash

Posted: Sat May 28, 2011 12:08 pm
by EricS
So, my fork is ten years old, and has an alloy steer tube bonded to carbon, and I weight 900 N (200lbs for the non-metric crowd).

Any suggestions?

Eric

Re: broken carbon fork that caused crash

Posted: Sun May 29, 2011 8:47 pm
by 4827north
Lister Farrar wrote:
Josh.E wrote:did that fail at the interface to the metal steertube? bonding metal to carbon was one of the last things the bike industry managed to figure out how to get right
Haven't seen it up close, but it looks like the carbon blades came off some kind of alu crown legs.

How long ago did they get that right? Before or after my family's carbon forks were made? (gulp)
It was an old Time fork. They used to bond carbon forks to an alu crown. Not the smartest design as thats a high stress area. Id say if you're riding any carbon carbon/ alloy fork older than 2004, I'd seriously consider replacing it. At the very least have it inspected.

Re: broken carbon fork that caused crash

Posted: Mon May 30, 2011 9:05 am
by 4827north
EricS wrote:So, my fork is ten years old, and has an alloy steer tube bonded to carbon, and I weight 900 N (200lbs for the non-metric crowd).

Any suggestions?

Eric
This is the fork on your Litespeed? 43mm to 44mm rake most likely. Check out the "dark deals" at Enve Composites. Or, if they are out of stock on the Old Edge labelled forks, I can get a deal on an Enve 2.0 for you.

Re: broken carbon fork that caused crash

Posted: Mon May 30, 2011 9:22 am
by John D
EricS wrote:So, my fork is ten years old, and has an alloy steer tube bonded to carbon, and I weight 900 N (200lbs for the non-metric crowd).

Any suggestions?

Eric
Eric...I suggest that we get to work on a new race kit designed specifically for us 900N TS riders. Perhaps something with thin vertical striping to make us appear longer and leaner? So as not to clash with the "Tripleshot Spinnakers" kit, we could dub this the "Tripleshot Doublewide" kit. :P

J.

Re: broken carbon fork that caused crash

Posted: Mon May 30, 2011 10:15 am
by JohnT
My 1998 Klein took at hit that pushed the front wheel back past the down tube, but the carbon did not break or become separated from the alu steer tube (Icon brand fork I think). Not only was the steer tube bent, the head tube (steer tube goes inside this) was pushed backwards into the down tube (just a little). So the frame was destroyed. Old doesn't necessarily mean substandard.

JT

Re: broken carbon fork that caused crash

Posted: Mon Jun 20, 2011 12:50 pm
by Lister Farrar
update: Several members of Tristars took their bikes into Trek Procity for a check after this accident. One found a broken hub, another had a crack in a carbon fork.

Re: broken carbon fork that caused crash

Posted: Wed Jun 22, 2011 10:51 am
by arfenarf
By contrast, I took my bike (11-y-o Trek 2300) into Pro City and they kind of rolled their eyes at me and told me there was nothing they could do apart from eyeball it for any grossly obvious problems.

Re: broken carbon fork that caused crash

Posted: Wed Jun 22, 2011 11:28 am
by Lister Farrar
Kate, was that a 'legal liability' reaction, or really believing they can't tell anything? Hard to believe Carolyn's fork showed no symptoms at all to a practiced eye. Not even a hair line crack under a bright light?

I heard a rumour from Fort Street that a guy in Sidney is planning to offer non-destructive testing of some kind. No details tho.