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Are Ultegra double and triple BBs the same?(2 posts)

Are Ultegra double and triple BBs the same?Painter
Jul 13, 2001 2:10 PM
Do Ultegra 9spd double and triple bottom brackets use the same spline pattern?

I'm looking at upgrading my crankset, but want to know if the 109mm BB and the 118.5 BB have the same splines and are compatible with both double and triple cranksets. (I think I need the extra width of the triple BB.)


Yupgrzy mnky
Jul 13, 2001 2:22 PM
Spline pattern is the same for 105, Ultegra, and DA no matter the length or number of chainrings.

Here's the rub - the double BB is too short for the tripple crankset (inner CR) and the triple BB is too long for the double crankset (chain line). Actually you can get away with the later case, but your chain line will be crappy and you double will not shift any better than the triple (normally it does). Ultimately the BB is a very cheap part to buy.