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  1. #1
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    help for spinning bolt in carbon 5.7

    Hi guys, hopefully some one from pivot can help with this problem. I have a friend I have convinced to buy a carbon 5.7, but the carbon frame has a bottle cage bolt that has been cross threaded and stuck half way in. The bike shop wants to get it repaired by pulling the armor off and re gluing the threaded insert then sticking the armor back on. i would like to know if this would work ok and if the nut insert is normally glued in or if it is a compression nut that clamps on the carbon. please see the pic for a btter idea.

    thanks
    Attached Thumbnails Attached Thumbnails help for spinning bolt in carbon 5.7-bolt.jpg  


  2. #2
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    Those are in fact a compression nut. If you can find a shop with the correct tool it's an easy fix without removing the rubber guard (it's not necessary to remove it for this repair)
    Desert Sunset Calls/Upward, Pain, Perseverance/Welcome Solitude

  3. #3
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    Google the term 'rivnut' and 'DIY rivnut tool'. The tool itself is just a long bolt, a nut and a snug fitting steel plate.
    You'll need to remove the damaged insert without making the hole any bigger, then insert a new alloy rivnut (the remnants of the old one may need to come out via the hole in the bottom bracket). Rivnuts come in all different sizes. You'll need a 5m inner thread and the OD needs to match the hole in the frame.
    Alloy rivnuts only need a small amount of tightening to hold in place so don't get carried away.
    I fitted one in a carbon Yeti; it took all of 10 minutes and cost about $5. Alternately, take it to a knowledgable and helpful store and get them to do it. Only real hassle can be fishing out the old bits if they fall inside the downtube.

  4. #4
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    Sounds better than removing the rubberized armor. One more question though, if its a compression
    nut how do you get it out without taking some of the carbon that is compressed between the nut?
    Thanks for the help guys so far your info makes more sense than what he was told.

  5. #5
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    The only way I've ever removed these without causing more damage is with a countersink bit similar to this:
    Buy Trend Rose countersink 20mm countersink diameter MPN: 49/71X10MMHSS at www.diytools.co.uk - Your Online Shop for Rose Countersinks

    This tool will cut the aluminum in a controlled manner with minimal chance of damaging or enlarging the existing hole. You'll still have to get the inner portion of the nut out of the frame by shaking it out of the BB..I don't remember what size tool we use normally, the one in the link is just an example.
    Desert Sunset Calls/Upward, Pain, Perseverance/Welcome Solitude

  6. #6
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    I got the old bits out by drilling, gradually stepping up in size until the metal gave in. This happened before my drill bit got anywhere near the carbon. A dremel tool could also be helpful. Just take it very slowly.
    The rivnut doesn't squash or crimp the carbon, it expands slightly in diameter to plug itself into the hole - that's why it's important not to make the hole too big when removing the old one.

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