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  1. #1
    scholar and gentleman
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    rubbing sound when turning new carbon fork only to LEFT of midline??

    Hi guys,

    I'm hoping you can help with a mystery that is slowly killing me inside. I've always been able to find mechanical answers by lurking before, but this one is pretty weird.

    I just finished installing a hylix branded rigid 29er carbon fork (carbon steerer, Hylix (eBay) Carbon 29" 29er fork) and am now getting a rubbing sound only when turning the steerer to *left* of center.

    The frame previously had a steel-steerer fork installed without problems. I left the headset, which was doing fine, and swapped the crown race to the new fork. I will say that the crown race fit was *very* tight, but it appears to be on evenly and I don't see any odd gaps or interferences. I took apart the assembly twice to check for presence and alignment of all the headset elements. No cables, etc installed as of yet to cause spurious noises.

    There is no notchiness that would suggest any new problem with the bearings. In fact, turning the right of center the fork rotates smoothly as you'd expect after appropriate bearing preload from the compression plug. The rubbing sound to the left is "smooth", so to speak, without clicking or notching, and is accompanied by a significant increase in resistance to turning. Pre-rotating the bearings half a turn before fork installation doesn't affect the angle where the rubbing starts.

    I've got this suspicion that the built-up area on the steerer immediately above the crown race could be rubbing on the inside of the lower headset cup for half of the fork rotation, but can't prove it to myself.

    If this is the case, how would I know? And what would I do? I'm new to carbon bits but kind of expect to be told that the built-up area can't be sanded and I'll have to ship the fork back to China... How about the inside of the headset cups, or alu. head tube?

    Thanks in advance

    Phil
    Honi soit qui mal y pense

  2. #2
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    Quote Originally Posted by Turduckenator View Post
    I've got this suspicion that the built-up area on the steerer immediately above the crown race could be rubbing on the inside of the lower headset cup for half of the fork rotation, but can't prove it to myself.
    Turn it a few times, take the fork out. If it's marred/notched, you know that's the problem. My money, for what it's worth, is that your initial assumption was correct, as far as the crown race not being seated correctly. If you don't have the proper installation tool, bring it on over to your LBS or a bud or does, and give it a whang or two, to see if your problem goes away.

    Obviously, since you didn't have this issue with the old fork, it's something about the new installation.

  3. #3
    scholar and gentleman
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    So I carefully took the lower cartridge bearings apart on a hunch and found they were actually in pretty rough shape. Cleaned, regreased, carefully reassembled, and now the rubbing is there but in the posterior half of the fork rotation (i.e., the half I don't need).

    The steerer itself wasn't gouged or marked, so I guess there's no direct contact there.

    Didn't have the opportunity to bang on the crown race again. Planning to replace the bearings and the crown race while I'm at it, and see if that fixes it.
    Honi soit qui mal y pense

  4. #4
    Plays with tools
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    You could coat the crown with a paint pen and see if the paint gets rubbed off and then you'll know if it's an actual interference or just a bad bearing.

  5. #5
    Trail Tire TV on blogger
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    Quote Originally Posted by Turduckenator View Post
    So I carefully took the lower cartridge bearings apart on a hunch and found they were actually in pretty rough shape. Cleaned, regreased, carefully reassembled, and now the rubbing is there but in the posterior half of the fork rotation (i.e., the half I don't need).

    The steerer itself wasn't gouged or marked, so I guess there's no direct contact there.

    Didn't have the opportunity to bang on the crown race again. Planning to replace the bearings and the crown race while I'm at it, and see if that fixes it.
    well with that said,.. I'd guess your bearings are out of round.. or you've ovaled the bearing cups...you have cartridge not sealed bearings? you can get new bearing rather cheaply.. or just replace the headset.. low-mid line headsets are rather inexpensive
    Going to try and bring Trail Tire TV back. go take a look... http://trailtiretv.blogspot.com/

  6. #6
    scholar and gentleman
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    After a new crown race and what seemed like ages waiting for the right replacement cartridge bearings, I finally got around to replacing them....

    ...and the rubbing sound is still there. It's present through a smaller angle, though, and the steering performance doesn't seem to be affected.

    I'm tired of fooling with the damn thing and loath to shell out for a new headset at this point, especially after the cost of the new parts. I wonder if the crown just isn't faced properly for the race or if there's something out of parallel in the steerer given the origin of the fork. I did have to cut the new crown race with a Dremel to avoid jamming it on with massive brute force like the old one (which I realize is controversial enough on its own to have launched several past threads....)

    If thomllama is right and the cups are ovalized I guess I'll eventually start having real problems with knocking/whatever eventually, and just replace the headset then.

    FWIW, thanks all for the input!
    Honi soit qui mal y pense

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