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Thread: Carbon Question

  1. #1
    All around nice guy BRANDUNE's Avatar
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    Carbon Question

    If a full carbon fork has a crack at the top of the steerer is it still safely useable with a proper expander, and or are there any other solutions to fixing it. I dont know much about carbon but my original thought was to drill out the bottom of the crack as top stop it from continuing and then gluing it up and using a good expander. ANY HELP WOULD BE GREATLY APPRECIATED

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    Senior Member serpico7's Avatar
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    Sounds like a bad idea. But if you go ahead with it, please include me in your will.

  3. #3
    vasracer
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    If you have some length on the steerer tube cut it down to where the crack ends. As for your original idea, not smart.

  4. #4
    Senior Member rideorglide's Avatar
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    Quote Originally Posted by BRANDUNE View Post
    If a full carbon fork has a crack at the top of the steerer is it still safely useable with a proper expander, and or are there any other solutions to fixing it. I dont know much about carbon but my original thought was to drill out the bottom of the crack as top stop it from continuing and then gluing it up and using a good expander. ANY HELP WOULD BE GREATLY APPRECIATED
    No way. What caused the crack in the first place? If it was a crash, you would be advised to toss the fork.

    Otherwise, you'd have to cut below the crack, but even then you can't be sure the thing isn't compromised. The glue will likely shear anyway at the crack line. A proper repair for fiberglass layup, even carbon fiber is to bind with another glassed on layer, but with a bike fork, that just isn't an option.

    It ain't worth the $$ for your body. I have a $300 carbon steerer on mine, and if I hose it in any way, I understand it's outta there, no questions asked, cos the next time I am descending a hill at 40 mph down a hill, I don't want any question in my mind. The injuries don;t seem like much when you are young sometimes, but they add up to expensive bad news as you get older. Keep your body so you can cycle to a ripe old age.

  5. #5
    cab horn
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    Quote Originally Posted by BRANDUNE View Post
    If a full carbon fork has a crack at the top of the steerer is it still safely useable with a proper expander, and or are there any other solutions to fixing it. I dont know much about carbon but my original thought was to drill out the bottom of the crack as top stop it from continuing and then gluing it up and using a good expander. ANY HELP WOULD BE GREATLY APPRECIATED
    Please buy a new fork. Nothing is worth a hospital stay and/or plastic surgery.
    Mes compaingnons cui j'amoie et cui j'aim,... Me di, chanson.

  6. #6
    WNG
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    If you must use it at its current length, then it's toast. Time for a new fork.

    If you cut the steerer below the crack it may still be usable, but you'll have to inspect it further down to see if there are any hairline fractures too easily missed by casual observance.

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    It is probably safe to say... do NOT drill the stop crack propagation.

    A few questions, if you would:
    Where is the crack, extactly?
    Does it run vertically or horizontally?
    Are there any spacers above your stem, or, is the fork cut in the traditional method to be just below stem top?
    How long is the crack, and how what is the height of your stem?

  8. #8
    Senior Member LouD-Reno's Avatar
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    Ok, I have one where the apparent crack is vertical, at the rear of the steerer, that runs just the length of the stem clamp... the steerer length is cut just barely over the top of the stem. The crack doesn't appear to the naked eye to go past the outer layer of the tube, but obviously this may not be the case... It became/becomes apparent as a white line when the stem is tightened to approx 4.5 ft/p

    Your thoughts appreciated !!!

  9. #9
    Senior Member LouD-Reno's Avatar
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    Ps. "the steerer length is cut just barely over the top of the stem" without spacers.....

  10. #10
    vasracer
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    get a new fork, you have no room to do anything. Save yourself the headaches and alot of injury and just buy a new fork.

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