Removing Crank from Square Taper

redjeepǃ
redjeepǃ Posts: 531
edited December 2013 in Workshop
Hi,

I'm trying to replace the chain set on an old commuter bike my son uses. I've managed to replace the righthand (drive) side, but can't get the crank of the lefthand (none drive) side despite some gentle pursuation with a large rubber mallet.

Am I missing anything? I've removed the allenbolt but is there anything else holding it on other than years of grime? I've never done a square taper before.

I want to get it done this weekend as I said that I'd fix it up for him for Xmas.

Its a square taper set and in case its relevant, I've replaced the Sora with a lightly used 105.

Comments

  • hypster
    hypster Posts: 1,229
    You need a crank extractor for taper BBs like this one from Chain Reaction:

    http://www.chainreactioncycles.com/x-to ... -prod10181

    You should be able to get something similar from Halfords or the local bike shop.

    You screw the inner piece out and the screw the outer body on to the crank. If you look closely the crank arm should have a thread (not the Allen bolt you already removed) that the extractor screws on to. You then screw the middle piece in and it should pull the crank arm off. If it's been on there some while it might take quite a bit of force to get off the taper.

    HTH.
  • redjeepǃ
    redjeepǃ Posts: 531
    Thanks hypster. It caught me out as the other side pretty much fell of when I removed the allenbolt. I'll go and buy one now.
  • dennisn
    dennisn Posts: 10,601
    Don't forget to remove the washer BEFORE using the crank extractor.
  • Nairnster
    Nairnster Posts: 602
    It is sometimes possible to remove the bolt /nut then ride it until it loosens.

    But a crank extractor sounds like it's needed.
  • redjeepǃ
    redjeepǃ Posts: 531
    Bought the extractor and it worked like a charm. Thanks everyone.

Categories