Replace my carbon fork?
#1
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internettubes engineer
Joined: Feb 2012
Posts: 305
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From: Mesa, Az.
Bikes: 2012 Felt Z85
Replace my carbon fork?
So, I was involved in a head on accident on Wednesday... the thread that I started for that is here: https://www.bikeforums.net/showthread...ospital-today-).
Gist of the story, a shopping cart rolled into the bike lane; a car was in the lane next to me and I couldn't stop... I ended up hitting it probably doing 14-15mph.
My front wheel went pretty out of true (bike shop was able to save it, so I guess not taco'd)... and I went over the bars after hitting it.
I have a Felt Z85 w/ a carbon fork... the bike shop went over my bike checking the welds and the measurements making sure the frame wasn't bent or broken... they looked over the carbon fork and say the bike is good to go.
Is it just me, or would you guys be itching to replace the CF fork as soon as possible as well? I know they said it's okay, but I've read about catastrophic failures after crashes... and a fork breaking on me might end my love for cycling very quickly and abruptly. Or am I just over-reacting / thinking too much into this?
Gist of the story, a shopping cart rolled into the bike lane; a car was in the lane next to me and I couldn't stop... I ended up hitting it probably doing 14-15mph.
My front wheel went pretty out of true (bike shop was able to save it, so I guess not taco'd)... and I went over the bars after hitting it.
I have a Felt Z85 w/ a carbon fork... the bike shop went over my bike checking the welds and the measurements making sure the frame wasn't bent or broken... they looked over the carbon fork and say the bike is good to go.
Is it just me, or would you guys be itching to replace the CF fork as soon as possible as well? I know they said it's okay, but I've read about catastrophic failures after crashes... and a fork breaking on me might end my love for cycling very quickly and abruptly. Or am I just over-reacting / thinking too much into this?
#3
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Joined: Apr 2009
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From: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
There's no way we can advise you since we can't examine the fork and have no basis for assessing the impact energy. If the shop who saw the entire bike felt the fork was OK, it's hard to overrule them. BTW- t]did they remove the fork and examine it completely including the steerer? Did they also examine the frame, especially the area under the front end of the downtube.
Unfortunately carbon has zero ductility, and so doesn't bend and show damage the way a metal frame would. It's sort of digital, it either looks (and probably is) perfect, or it's obviously broken. If I were riding the bike I might have some idea of the energy involved and would make a decision, but nothing is certain so for anything more than a very light impact (less than the typical deep pothole), I'd replace it based on my likelihood/consequences assessment.
My thinking is that I'm willing to accept a relatively high risk of failure if the consequences are minor, but my risk tolerance devreases as the possible consequences get more severe. Since the possible consequences of a fork failure, especially a base of steerer failure, are off the top of the chart (possible death is not just legal boilerplate), my risk tolerance would approach zero, and if I had any loss if faith in the fork, I'd replace it.
Another way to think about it is would you trust the fork on a high speed descent, maybe on a somewhat bumpy road? If not, there's no way you can enjoy the bike, and have a sense of comfort, so it has to go, even if it seems OK.
Unfortunately carbon has zero ductility, and so doesn't bend and show damage the way a metal frame would. It's sort of digital, it either looks (and probably is) perfect, or it's obviously broken. If I were riding the bike I might have some idea of the energy involved and would make a decision, but nothing is certain so for anything more than a very light impact (less than the typical deep pothole), I'd replace it based on my likelihood/consequences assessment.
My thinking is that I'm willing to accept a relatively high risk of failure if the consequences are minor, but my risk tolerance devreases as the possible consequences get more severe. Since the possible consequences of a fork failure, especially a base of steerer failure, are off the top of the chart (possible death is not just legal boilerplate), my risk tolerance would approach zero, and if I had any loss if faith in the fork, I'd replace it.
Another way to think about it is would you trust the fork on a high speed descent, maybe on a somewhat bumpy road? If not, there's no way you can enjoy the bike, and have a sense of comfort, so it has to go, even if it seems OK.
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FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
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