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  1. #1
    The Brutally Handsome
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    Stripped Titanium BB?

    I'm not sure if this is the right place to ask, but I was hoping you guy's might have some advice or answers. Anyway, I recently picked up a titanium frame and while attempting to pull the old XTR square-taper cartridge bottom bracket, I ran into a serious issue. The short version is that the cartridge just keeps turning and turning but will not extract itself.

    The long version is that it was very difficult to get going so I hit it with some penetrating oil. It was still very slow and the splines were beginning to become badly stripped. I had about 15mm of the cartridge out so I went to use a pipe wrench on the exposed threads. Well, that tore up the threads on the cartridge and after a few more turns, I realized that the cartridge was no longer extracting itself. In other words, it was turning freely, but staying the same place. I recon there was at least another 5-10mm of threads left inside the shell. Anyway, I was so scared that I screwed it back in (went back in nicely!), hoping that my problems would magically go away, but I know that this is a serious problem. I'm guessing that the titanium threads inside the shell re-cut the threads on aluminum BB cartridge but I don't know enough about frames and materials to say for certain. In my panic, I probably did more damage. So, does anyone have advice or ideas what to do? Should I leave it in and ride or is there a way to get the cartridge out? I'm afraid to ride it and I would really like to solve this the right way so any help appreciated!
    Last edited by Sizzler; 03-23-2010 at 12:57 AM.

  2. #2
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    A while back the local bike shop (i'm friends with the owner) had a customer with carbon road frame where the fixed cup had jammed into place from road and body salts, with the spindle out i made a quick little fixture for holding the frame in my handy little milling machine ,with a small solid carbide mill i very carefully milled the cup thinner and thinner until until it could be pealed out by curling it up out of the threads. It's probabely possible to do the same with a dremel tool, very carefully get the cup out and chase the threads.

  3. #3
    meh....
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    so the cartridge will thread out to a certain point, then stop, but still turn? Do you have the non-drive side cup removed? Either way, I'd thread the cartridge out all the way it will go, then give the spindle a love tap. You should be able to tell whether the cartridge is still in threads, or if something else is holding it in.

    I don't think there's much chance of the aluminum ruining the TI threads.

  4. #4
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    There's not a cable guide screwed into the bottom of the shell, where the bolt might be sticking up and catching something on the BB?

  5. #5
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    Quote Originally Posted by dr.welby
    There's not a cable guide screwed into the bottom of the shell, where the bolt might be sticking up and catching something on the BB?
    Great advice.

    If you got most of the BB out but still have a cup, etc stuck in the frame you can dremel the cup until it's thin enough to peel out, as HerbN said. I have a milling machine but the last seized cup I did was with a dremel - it was faster than setting everything up. You only need to cut it in one spot so that you can fold it in on itself, effectively reducing the diameter.

    I doubt the Al threads on the BB did much damage to the Ti -- Ti is tough stuff.
    Too many bikes, not enough time.

  6. #6
    The Brutally Handsome
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    Acoms razor: in my sleep deprived state, I failed to unscrew the cable guide out of the bottom shell. Thanks for the advice dr.welby, after taking that out, I was able to pull the bottom bracket without issue, and the Ti threads look fine. Thanks for everyone's suggestions, this is a load off my mind!
    Attached Thumbnails Attached Thumbnails Stripped Titanium BB?-bb.jpg  


  7. #7
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    Quote Originally Posted by Sizzler
    Occums razor: in my sleep deprived state, I failed to unscrew the cable guide out of the bottom shell. Thanks for the advice dr.welby, after taking that out, I was able to pull the bottom bracket without issue, and the Ti threads look fine. Thanks for everyone's suggestions, this is a load off my mind!
    Glad it worked out!

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