Bicycle Mechanics - Bottom Bracket: Shimano or something else?

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PDA
|3iker
07-20-10, 05:05 PM
I'm thinking to convert my triple to a double and am looking for a BB to go along as well. Current BB is a square taper one. Coupla questions:

- Does it matter what sort of external BB when it comes to triple to double?
- Does Shimano still use Octalink or are they external BB as well? What about ISIS?
- How do I determine the size of the BB that I need?
- What do you think of the Truvative GXP BB vs. a Shimano Tiagra BB?
- Italian vs English? What does that mean?

thanks.

badamsjr
07-20-10, 05:15 PM
Most square taper BB's will work with square taper cranks. I did hear of a Mavic crank splitting when installed on a shimano BB, but do not know this as fact. Octalink was in between square taper and external BB's (Shimano). Isis is different from Octalink, and not compatible. Some external BB's play nice together, others do not. If you buy an external BB crankset, it should come with the appropriate BB. English thread is what many Japanese and American bikes have as standard. Italian and French are different, and not compatible.
Bianchigirll
07-20-10, 05:28 PM
more than likely you need an English BB. however thetype and length of the SPINDLE is determined by the model of crank you are using. switching from a triple to a double crank you likely need a shorter spindle.

if you are unfamiliar with mechanics and changing BBs buy the one that matches your new double crank.