Viewing 7 posts - 1 through 7 (of 7 total)
  • Repairing crank thread – possible? worth it?
  • savoyad
    Full Member

    My pedal stripped out a chunk of the thread in my road bike driveside crank.

    I’ve seen a few old threads where people ponder tapping it and/or using helicoils to revive cranks in this state. Is it worth it?

    Assuming I don’t want to buy the tool(s), is it a job any LBS can do, or is it more specialist than that?

    And this chainset was (annoyingly) destined for ebay in the near future. Will a repair restore it to sellable condition or is it really a bit botch normally?

    I’ve lost ~half the thread I guess. Photos (click for bigger!)

    Full Member

    Any decent bike shop should be able to helicoil them – usually a tenner a crank, far cheaper than buying the kit.

    Free Member

    That looks like an insert in the crank, which *may* complicate things.

    Full Member

    Even if you strip all the threads out completely, an engineering shop would be able to affect a repair. I know, because I’ve had it done.
    Dunno about cost, my uncle did mine, but it can definitely be repaired.
    Top tip for future reference, if you loan cranks out, make sure your mate knows how to fit pedals 🤨🤨

    Full Member

    As above if it’s an insert then Heli coil might not work.

    Free Member

    You can normally ream out the crank arm and fit a threaded insert, more durable than a helicoil. Some crank arms are not suitable.

    I use this style, I would charge £25 for reference

    Park process overview (better to shorten the insert to the correct length prior to installing in my opinion, grinding a the insert fitted to a customers crank is a hack)

    Online options;

    Free Member

    Pearce offer this service. I sent them some really mullered XT’s once that were properly ovalised when the thread went. They coudn’t do the job but sent the cracks back FoC.

Viewing 7 posts - 1 through 7 (of 7 total)

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