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Old 04-09-13, 01:47 PM   #1
jfmckenna
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Bent Fork Dropout

What do you think? Bend it back and forget about it or toss it and save a trip to the emergency room? It's an Alpha Q CS20.

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Old 04-09-13, 01:50 PM   #2
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That looks like aluminium, and if it is, I wouldn't trust it after it'd been straightened.

If it turns out it's actually steel, it might be a different story.
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Old 04-09-13, 01:52 PM   #3
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Old 04-09-13, 02:08 PM   #4
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That looks like aluminium, and if it is, I wouldn't trust it after it'd been straightened.

If it turns out it's actually steel, it might be a different story.
+1 - If it's Alu, then fugeddaboudit - it's toast. If it's steel, though, it could probably stand at least one cycle of being straightened.

That's a carbon fork though, isn't it? What the hell happened to it to cause that bent dropout? If anything significant, I would also be worried about the condition of the main body.
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Old 04-09-13, 03:51 PM   #5
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I think the dropout itself can be straightened, aluminum or not, but what caused the bend? What would concern me is damage to the bond between the dropout and the fork leg from the whack the dropout must have taken.
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Old 04-09-13, 06:17 PM   #6
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Stupidity caused the bend. Yakima bike rack on the roof, rear wheel facing forward, fork mounted properly, rear wheel strap mount not clamped, high way speeds, bike flips off rack and rotates causing bend.
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Old 04-09-13, 07:52 PM   #7
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Stupidity caused the bend. Yakima bike rack on the roof, rear wheel facing forward, fork mounted properly, rear wheel strap mount not clamped, high way speeds, bike flips off rack and rotates causing bend.
Ouch! Again, it's not only the dropout that is the concern but the bond between the dropout and the fork blade.
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Old 04-09-13, 09:04 PM   #8
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There's a certain forgiveness in forks due to the redundancy. I'd probably give it a go at straightening, and if it went well, I'd ride the fork. But not forever, consider it a short term deal while you seek out a replacement.

In all honesty, I wouldn't expect a catastrophic failure because it's only one of two blades, but when I'd descending a grade at 40mph, I don't want to worry about what's between the road and me. I'm that way about stuff in general. If I drop the front wheel into a deep pothole (the kind that instantly scrubs about 5mph of my speed) I don't want to then worry about what it might have done to the fork.

Same exact situation on the rear dropout and I'd fix it and forget it and ride it as if it were new for years.
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Old 04-10-13, 06:54 AM   #9
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*sigh... yup a new fork it will have to be, I just won't stop thinking about the dangers and I don't need that on my mind, plus what kind of a jerk would I be if it broke and I crashed out 15 other guys?

Time to go shopping.
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Old 04-10-13, 07:09 AM   #10
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Mind you - it's said that carbon tends to fail 'all at once' as it were - like if there's a crack in a carbon fork/frame that goes into the actual weave, then it can create a weak spot where it can fail.

Although the twisting moment that fork experienced would have been pretty high I would imagine to bend the dropout that much, the fork obviously managed to take it OK and not break.

What I'm trying to get across, I think, is that metals like Alu have a finite number of stress cycles before they fail, but this doesn't apply to carbon AFAIK.

So that fork might well be perfectly OK so long as the dropout is replaced, and that the replacement is properly glued into place.

It might be a *lot* cheaper than buying a new fork, and you should be able to ride with your mind at rest.

EDIT: As a matter of interest, how did the wheel(s) and the rest of the frame fare in this accident?
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Old 04-10-13, 12:28 PM   #11
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Mind you - it's said that carbon tends to fail 'all at once' as it were - like if there's a crack in a carbon fork/frame that goes into the actual weave, then it can create a weak spot where it can fail.

Although the twisting moment that fork experienced would have been pretty high I would imagine to bend the dropout that much, the fork obviously managed to take it OK and not break.

What I'm trying to get across, I think, is that metals like Alu have a finite number of stress cycles before they fail, but this doesn't apply to carbon AFAIK.

So that fork might well be perfectly OK so long as the dropout is replaced, and that the replacement is properly glued into place.

It might be a *lot* cheaper than buying a new fork, and you should be able to ride with your mind at rest.


EDIT: As a matter of interest, how did the wheel(s) and the rest of the frame fare in this accident?
No problem with anything else. It simply raised up off the rack and flopped over. Definitely an 'Oh Sh**' moment.
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