Is my BB gone?

Initialised
Initialised Posts: 3,047
edited October 2012 in The workshop
There was a thunk when I was pushing hard on the cranks it had done this a few times but this time there seems to be excess play on the cranks, and so much so that the left feels loose when riding. Most likely the BB right?

Bike is a late 90s Giant MTB I replaced the BB a couple of years and maybe 8000-12000 miles ago and the numbers 118 and 68 square tapered stick in my head does that sound about right for life span and dimensions?

There's an Evans and a Halford that I can get to at lunch or on the way home so a link to exactly what I need would be greatly appreciated.

Thanks.
I used to just ride my bike to work but now I find myself going out looking for bigger and bigger hills.

Comments

  • dg74
    dg74 Posts: 656
    I'm currently inspecting a customer bike for same thing!
  • gosport_commuter
    gosport_commuter Posts: 185
    Make sure the left crank is bolted up nice and tight first, but yes 8-12k miles sounds pretty good going to me. Not 100% on the sizes, but its prolly either 68mm or 73mm.
  • The Rookie
    The Rookie Posts: 27,812
    Sounds like a 68mm BB shell and 118mm square taper axle.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • Initialised
    Initialised Posts: 3,047
    That's the one. To I picked one up and now have the cranks off and the BB seems to be seized. Have covered it in GT85 to soak up in over night. I know it had a good innings but I'm going to blame the floods for this one.

    Any tips on freeing up a seized BB?

    I guess I can always take it to an LBS tomorrow if I can't get it out.
    I used to just ride my bike to work but now I find myself going out looking for bigger and bigger hills.
  • gosport_commuter
    gosport_commuter Posts: 185
    Make sure you are turning it the correct way, one side is a left handed thread, and the other is not.
  • dg74
    dg74 Posts: 656
    Initialised wrote:
    That's the one. To I picked one up and now have the cranks off and the BB seems to be seized. Have covered it in GT85 to soak up in over night. I know it had a good innings but I'm going to blame the floods for this one.
    co
    Any tips on freeing up a seized BB?

    I guess I can always take it to an LBS tomorrow if I can't get it out.

    or you could ring me - www.northtynebikerepair.wordpress.com
  • Initialised
    Initialised Posts: 3,047
    Cheers, got it sorted now. It's basically brute force and leverage.

    http://www.cycle-systems-academy.co.uk/ ... ts?start=2

    Big arms that that guy's probably help too.

    I don't think the tube I used is going to fit the VAX any more o_O

    @Gosport: oops, drive side is threaded backwards like pedals so you can't unscrew them by pedalling.

    Bit late for a test ride around the West End.
    I used to just ride my bike to work but now I find myself going out looking for bigger and bigger hills.

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