Fork failures

Discuss light weight issues concerning road bikes & parts.
youngs_modulus
Posts: 512
Joined: Wed Sep 20, 2006 1:03 am
Location: Madison, WI USA

by youngs_modulus

I remember something along those lines, but I also remember my 2007 R3 came with a Wolf fork, but it was recalled and replaced with a 3T fork. If the shipping boxes were the only issue, why would they have gone to 3T forks? Maybe they didn't want the liability that came with a house-designed fork...who knows?

by Weenie


blue151
Posts: 38
Joined: Fri Jun 11, 2010 2:39 am

by blue151

@miller

Nope, I haven't noticed anything the last couple times i pulled the fork off. But having said that, I wasn't specifically looking for damage (I have layed the bike down in a few corners but never had a front on collision)

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Asteroid
Posts: 222
Joined: Tue Jul 26, 2016 8:43 pm
Location: Los Angeles, California

by Asteroid

youngs_modulus wrote:You say "full carbon fiber Trek," but it's unclear whether "full carbon fiber" means the frame or the frame and the fork.

I'd love to see a photo of the broken pieces. I'm a mechanical engineer with a lot of experience in composite structures, so I'm not just idly curious.

I have a friend who sustained an ugly brain injury when his Manitou II fork crown suddenly gave way. A design flaw created a stress concentration, which in turn initiated a crack and led to catastrophic failure. That fork, it turns out, had been recalled because of the flaw.

I seriously doubt that there's a design flaw in your friend's fork crown, but there could have been a problem with the manufacturing. In that case, the most likely culprit is a large void in the matrix (assuming the fork is entirely carbon). If so, a photo may show that void or possibly another flaw.

It's also possible that the guy put the bike on the roof of his car and then tapped the top of his garage with the bars (or something like that). I'm not trying to blame the guy you rode with, but all of these things (design flaw, manufacturing defect, user-inflicted damage prior to failure) are possibilities. Pictures would help, but they may also be entirely inconclusive.

To be honest, I think it's a bit early to talk about "pursuing a case" (suing?) without any evidence about the root cause of the failure. The guy might know in the back of his mind that he hit a curb pretty hard two months ago, or he may have clear evidence of a manufacturing defect. None of us here has enough information to say either way. Regardless of that little question, I hope your riding partner heals quickly and is back on a new bike soon.


The OP asked for instance of a fork failure, so I gave one. Big group Saturday ride on July 15 of about sixty-plus riders. I did not know either of the riders who crashed, but with tons of blood on the pavement and one dude having difficulty breathing with broken ribs, it was a sickening sight. I glanced over and noticed the first one down rode a newer high-end Trek. No idea if it was full carbon steerer, but the newest high-end models seem to use that mix. You are reading way too much into it. A few of us conjectured that a snapped fork steerer seemed unusual. And, if it happened to us, we'd be pissed and likely to find the root cause and possibly pursue restitution. Paramedics air-lifted him out via helicopter to get him to a proper hospital.
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tonytourist
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Location: 93306

by tonytourist

What ride were you on?

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WinterRider
Posts: 440
Joined: Tue Feb 05, 2013 2:46 pm

by WinterRider

youngs_modulus wrote:I remember something along those lines, but I also remember my 2007 R3 came with a Wolf fork, but it was recalled and replaced with a 3T fork. If the shipping boxes were the only issue, why would they have gone to 3T forks? Maybe they didn't want the liability that came with a house-designed fork...who knows?


Ah.. the resin 'word'.. liability... or in reality how to avoid it.. the responsibility for the product being marketed. Pre-plastic bike forks it was rare to hear of a fork issue.... post-plastic plastic resin forks it's common place. Why.. does the buying public accept this? "Oh.. that'll happen to someone else". Bullsh*t... what goes around comes around... your next.

Then the long blatter of 'fine print' attached to bikes on display... I use readers and can't even determine wording using a magnifier... what.. is being hidden? In fact it's the escape clause for these "bike companies"... the instructions for plastic forks essentially means the rider is supposed to be nearly a mechanical engineer.. to determine what the severity level is for road impacts... when to climb off and walk home post pot hole encounter. That is more bullsh*t... a huge load.

It's what it is: this is the 21st century. Bottom $$ line is paramount now... human lives are just cost factor.. "law" now mitigates that corp risk.

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Asteroid
Posts: 222
Joined: Tue Jul 26, 2016 8:43 pm
Location: Los Angeles, California

by Asteroid

tonytourist wrote:What ride were you on?


7:45 Montrose.
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