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im building up an old racer from scratch, so i dont have an old BB to replace with a new one. how do i work out what size BB i need?
im going to be running a compact double x 9 speed
cheers
It's the Chainset that determines the bb mostly , what Chainset are you Useing ?
Sheldons website has a large list on It
Yep, very true, the chainset determins the BB axle length in most cases.
If it's an actual OLD racer you'll need to give consideration to the threads too.
hi
its not very old (reynolds 531 90's i think)
the chainset is an old shimano i have hanging around. doesnt say anything on it regarding BB axle length
It won't say on it , you need to look up the model to see what bb.
There is probably a number stamped into the back of the crank arms
Something like fc-6500
The go to sheldon Browns website and look up which bb is recomend
ahhhh
thanks