Seized BB71 - Damage to crank axle?

peat
peat Posts: 1,242
edited March 2015 in MTB workshop & tech
Hi all,

After struggling the last couple of times i rode my MTB, I worked out where the resistance in the driveline was. The non-drive side bearing on the bottom bracket has seized.

I know they are a bugger to replace, so i'm braced for that. But, I have ridden it for at least 6 hours in it's current state with, as it turns out, the axle rotating against the inner run of the bearing. Will that have damaged the axle do you reckon?

Comments

  • warpcow
    warpcow Posts: 1,448
    Mibbes aye, mibbes naw.
    Commie Meta SL
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  • The Rookie
    The Rookie Posts: 27,812
    Remove and find out.....given you could still turn it it sounds like it wasn't dragging too badly, so maybe you'll be lucky.
    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.
  • peat
    peat Posts: 1,242
    I had it apart last night, the contact area was slightly discolored and polished. I'm worried that, due to the tolerances, that it won't seat properly in a new bearing.

    Only one way to find out I guess.

    I've reluctantly given up my hopes and dreams to get out off-road this weekend. sniff sniff.
  • The Rookie
    The Rookie Posts: 27,812
    Clean it and use a little bearing lock, simples.....
    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.
  • peat
    peat Posts: 1,242
    It went in fine, cheers all.

    I say 'fine', i think i put the spacer on the wrong side (non drive) so had to re-adjust my front mech. Seems to ride fine though. Will test it properly tomorrow.
  • The Rookie
    The Rookie Posts: 27,812
    If it's wrong, fix it now or you'll never get round to it!
    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.
  • njee20
    njee20 Posts: 9,613
    If you've got a 73mm BB shell you need one spacer on the drive side. If you've got a 68 you need two on the DS, one on the NDS.
  • peat
    peat Posts: 1,242
    It's a 73. As I say, i knawlsed it up, but it rides fine. I'll pick up another BB next time i'm at the LBS as I now know that it's not half the job I had built it up to be in my mind.

    I don't call them mistakes, I call them 'learning opportunities'.
  • jimothy78
    jimothy78 Posts: 1,407
    Peat wrote:
    It's a 73. As I say, i knawlsed it up, but it rides fine.

    But moving the spacer is such a simple job, why not do it now?
  • peat
    peat Posts: 1,242
    It's press-fit, to remove it is to destroy it.
  • The Rookie
    The Rookie Posts: 27,812
    Certainly shouln't do if done properly...
    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.
  • njee20
    njee20 Posts: 9,613
    Agreed.
  • peat
    peat Posts: 1,242
    care to enlighten me?
  • mamba80
    mamba80 Posts: 5,032
    Peat wrote:
    It's press-fit, to remove it is to destroy it.

    i fitted a new bb90 pf, it creaked so i removed it with a park tool bbt and refitted this time with silicon grease, the BB was absolutely fine and has been for sometime now.
  • peat
    peat Posts: 1,242
    hmm, ok. I will need to see about procuring a decent puller.
  • mamba80
    mamba80 Posts: 5,032
    http://www.koo-bikes.com/park-tool-bbt9 ... l-set.html

    i think if you sign up to their newsletter, you save £5 off your first order.
  • The Rookie
    The Rookie Posts: 27,812
    Do some online searching and you'll find a few 'ghetto' removal solutions as well.
    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.
  • peat
    peat Posts: 1,242
    Ta muchly.

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