Bottom Bracket Issues
I've recently bought an old racing bike (probably mid 80s)
Im doing it up and have have removed to original bottom bracket, which wasn't a sealed unit.
Im buying a new bottom bracket but i'm not sure what axel width to get. The axel on the original bike was 150mm long. Would a new Shimano UN26 or UN54 with a 113mm axel be ok? Or would i need one as long as the original?
are you measuring to the end of the studs or the square shoulders? the studs dont count. i would use a similar length
If the spindle has threaded stubs sticking out of each end and the cranks are held by nuts, then reptilezs is correct. Ignore the threaded stubs and measure from the ends of the square tapers.
Dimensions A, B, C, and D should match those of the original spindle as closely as possible.
The individual dimensions A,B and C are not selectable on a cartridge. You need to match D and the effect of A and C are only useful if the bb is not symetrical.
Originally Posted by JohnDThompson