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  1. #1
    mtbr member
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    Hope FNG Q? crank extractor stripped out...is i screwed?

    so, putting together a new frame for a SS build and was trying to use the Truvativ Isoflow square-taper cranks & BB off an older frame I had and when removing the crank from the BB I pulled the threads out instead of pressing the crank off the BB on the drive side.
    i normally watch the threads/extractor closely and try to make sure nothing like this happens, but this particular side had some threads already bunged up at the top, so there wasn't as many threads for the extractor to catch on to begin with. plus i was on lunch and trying to hurry so i could get to work putting together my new frame. stupid, i know.
    i don't want to continue to thread in the extractor and ruin the remaining aluminum that is still there if there is a way I can salvage it.

    so is this crank arm toast or is there some hope for this crank arm?

    any tips on removing the arm from the BB w/o ruining it??

  2. #2
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    You just learned something....

    very important. If the threads are "bunged" even a little, clean em up with a tap before you try to use them, and ALWAYS engage ALL the threads (bottom out the puller) before you attempt to pull a crank. You may be able to salvage it, or at least get it off without destroying it. But only if you have enough room to get a tap in there to clean up the ruined threads and have enough thread left to engage the puller. If not the only other way to get that crank off is with a tool that looks similar to a large tunning fork. It slides behind the crank arm and you beat on it till the crank arm comes free. This of course usually ruins the crank arm, and you can do damage to the frame if you are not careful. I'd try cleaning up the threads and then trying the puller again. But if that doesn't work your only recourse is to go with the beat it method. I'd have to see the crank before I could say for certain if you stand a chance with the puller. Anyway, you've got nothing to loose at this point, all you can do is try.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  3. #3
    Nouveau Retrogrouch SuperModerator
    Reputation: shiggy's Avatar
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    And be sure you are using a puller for square taper and not an ISIS puller.
    mtbtires.com
    The trouble with common sense is it is no longer common

  4. #4
    mtbr member
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    thanks guys,

    the problem that lead to this was when i pulled these cranks previously, i had just bought a new extractor tool and didn't notice the ISIS adapter on the end when i first threaded it in.
    it stripped the top half of the threads on the crank when i tried to remove the arm, when i pulled it out, i saw the ISIS adapter and removed it.
    the arm pressed off after that w/o an issue, but it left me w/ damaged goods.

    oh well...chock one up for experience.

    think i'm gonna go with a set of FMF BMX forged cranks, since it's gonna be a SS anyways.


    i'm gonna try to get a hold of my buddy w/ an auto repair shop and go borrow his bench press or a bearing puller, to get this arm off at lunch today.
    Last edited by pozzi; 08-08-2007 at 10:51 AM.

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