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Crank woes

marchantmarchant Posts: 362
edited March 2009 in The workshop
Okay, I've got an old bike which I'm intending to "renovate", ie strip down, replace tired and worn out parts with shiny new ones and if I like the new version, treat it to a respray and such, but I've hit a problem. Due to (unlikely) some sloppy assembly at construction or (probably) someone's over-enthusiasm the drive side crank thread is stripped and defies all attempts at removal. Would I be better served chucking it in a taxi and getting the LBS to minister to it, or get the drill out and have at it? Both crank and BB were destined for the bin and to be replaced, so the LBS option is more reasonable, but I'm reluctant to have the poor soul put through an ordeal like that and anyway, my intention was to do as much by myself as practical, without spending silly ££ on tools I'll use once.



  • wgwarburtonwgwarburton Posts: 1,863
    Unless this is one of those new improved BBs that needs a special spline tool, you can just unscrew the BB cup and take it off with the crank still attached....

    Failing that, borrow a three-armed-puller from mechanic and use that to pull it off.

    Cut the crank off the axle (it's aluminium, so relatively easy to cut. Once you've cut a slot it'll open up & slide off easily).

    Cut the axle & crank off with an angle grinder.

  • itboffinitboffin Posts: 19,964
    marchant can you take a pic and post it here?
    Rule #5 // Harden The censored Up.
    Rule #9 // If you are out riding in bad weather, it means you are a badass. Period.
    Rule #12 // The correct number of bikes to own is n+1.
    Rule #42 // A bike race shall never be preceded with a swim and/or followed by a run.
  • marchantmarchant Posts: 362
    I'll try, when it's sunny and I've figured out if my camera has a macro facility and I can hold it still enough. Don't laugh at my bike though...
  • nicklousenicklouse Posts: 81,520 Lives Here
    hacksaw or angle grinder and cut it off.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • If it's still ridable try riding it around (preferably on a quiet road close to home) without the crank bolts in as this may be enough to dislodge them.

    Failing that I wouldn't bother with a hacksaw as you'll be there all day. Best thing to do is to cut parallel to one of the faces of the bb axle with an angle grinder.
  • If you can get the other one off then you can try just hammering the axle out through the bb, this can be done sometimes, particularly with very cheap BBs.

    TBH for the amount of hassle, just LBS it, you can then get it faced (if you're having new external bb cranks fitted) and the new ones fitted correctly!
  • marchantmarchant Posts: 362
    I'm gettig the feeling that the LBS is my best bet, as I'm getting rid of the crank and intend to fit a new BB anyway. Given the price of even a cheap grinder, and that I'll only use it the once, and the awkwardness factor of it being the drive side it just seems easier in both the long & short term.
  • marchantmarchant Posts: 362
    Bloody thing refuses to budge, still! I got the adjustable hub out though; the bearing cage came out in five pieces, not counting the bearings. That'll explain the slightly rough feeling on turning the cranks.
    It's the drill tomorrow, and if that doesn't work the whole b*st*rd thing's going in the skip.

    Btw I undid the lockring and adjustable hub with my bare hands Rrrrarrr! :!:

    Update; got the BB out today (without pwer tools) and everything looks good. Now the hard part, deciding what parts to buy, making sure everything's compatible and doing it all as cheaply as possible. I'm even recycling an old set of grips...
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