Bottom bracket confusion

El Gordo
El Gordo Posts: 394
edited March 2010 in The workshop
Can anyone explain bottom bracket standards to me? I've never had anything other than square taper which has been OK but I'm in need of a new chainset and the better end of the market has moved on.

So now it seems we have Octalink and ISIS which are still internal cartridge bearings but with splines instead of square tapers. Are they any good? Do the cranks hold tight and do the bearings last?

Then there is Hollowtech II. This has external bearing cups - do they fit into the same shell as the old style BB? Is there any real advantage over Octalink?

Are there any other systems I should know about? I know BB30 needs an oversize shell so that's out.

I have a 9 speed system - will a chainset advertised as 10 speed work Ok or will the wider chain mess things up?


Thanks.

Comments

  • nicklouse
    nicklouse Posts: 50,673
    all threaded BBs use the same standards. you just need to know what standard you have.

    BSA or Italian.

    ISIS and Octalink are now a few years old and have been replaced mainly because ISIS BBs not last too long.

    TBH i would just replace the BB and fit new chain rings rather than changing the whole set up. If going for the External bearings you WILL need the BB shell faced.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown

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