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Upgrading Powerspline BB, straight swap?

contentedcontented Posts: 83
edited January 2014 in MTB workshop & tech
Hiya,
I have a powerspline 68 x 113 bottom bracket (for 47.5mm chainline - not sure what that bit means) and would like to swap it out as I'm looking at upgrading my cranks.
Will any other correctly sized bb just fit in its place or do I need to limit myself to certain types? Looking at hollowtech ii or octalink at the moment if that helps.
I'll buy the appropriate crank and bb tools for the job as they're a good investment anyway, but would like to avoid facing or anything that needs to be done by the bike shop.
Cheers :)

edit: would consider square taper or anything that's a straight replacement.

Posts

  • cooldadcooldad Posts: 32,599
    Pick the cranks, and then a BB to match. HTII comes with a BB, but it's external and you should get the BB shell faced.

    For cartridge BBs, spline length depends on the crankset and chainline required. The info will be in the manual with the cranks, or look on the manufacturers website.
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  • Ahh I'm with you, thanks.
    So HTii will need a bit of facing work, but looking at it, square taper will basically fit right in?
    I'll go for square then, I'm upgrading an entry level bike and there seems to be a few bargains for square taper that will still be a step up the ladder for me.
    Thanks very much for your help cooldad.
  • Ever thought they are bargains for a reason?

    If on a budget a Deore HTII is where the sensible money is.
  • supersonicsupersonic Posts: 82,708 Lives Here
    Bargains because people think ht2 is much better - it isn't always.
  • cooldadcooldad Posts: 32,599
    It was better for the manufacturers.

    If you want the best option without going HTII, I'd recommend Octalink. Still cheap, but much better than square taper.
    (Although saying that I still have ST on a couple of bikes, no hassles as long as you check the crank bolts. Once they loosen and you ride, the cranks are fubared.)
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  • Octalink is better, but pricier then. Fair enough, I'll go for Octalink if I can get something near the price of square taper.
    I'm never going to be pushing any component to its limit so it's more about ease of maintenance / upgrade and value for money.
    Thanks again very much for your help guys - another problem solved :D
  • Power spline bb's will only fit power spline cranks
    Octalink bb's will only fit Octalink cranks
    Depends on the kind of riding you do. Square taper cranks and bb won't last 5 mins if you are doing anything other than riding to the shop. It's all a question of how much money you want to spend. Go on crc and find a set of cranks you like, then get the bb to fit them and your frame. Shimano deore thru axle cranks are very good for the money
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  • supersonicsupersonic Posts: 82,708 Lives Here
    I used to do dh and trails on square taper cranks, get a shimano set up install correctly and they last.
  • cooldadcooldad Posts: 32,599
    Square taper cranks and bb won't last 5 mins if you are doing anything other than riding to the shop.
    Absolute rubbish.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

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  • Monty DogMonty Dog Posts: 20,614
    Square taper cranks and bb won't last 5 mins if you are doing anything other than riding to the shop.

    You'll still find 20 year old cranks with square taper cranks still going strong, whereas you're lucky to get a year out of any external bearing bottom bracket.
    Make mine an Italian, with Campagnolo on the side..
  • The RookieThe Rookie Posts: 27,757
    Depends on the kind of riding you do. Square taper cranks and bb won't last 5 mins if you are doing anything other than riding to the shop.
    I'm guessing you are still at school! ST is almost certainly the most reliable BB arrangement there is. It's a bit heavy, and it's not the stiffest, but reliable, absolutely.
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