Topic starter
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
Posted : 16/10/2016 6:57 pm
It's the Chainset that determines the bb mostly , what Chainset are you Useing ?
Sheldons website has a large list on It
Posted : 16/10/2016 8:54 pm
Yep, very true, the chainset determins the BB axle length in most cases.
Posted : 16/10/2016 9:45 pm
If it's an actual OLD racer you'll need to give consideration to the threads too.
Posted : 16/10/2016 10:17 pm
Topic starter
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
Posted : 24/10/2016 5:41 pm
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
Posted : 24/10/2016 8:09 pm
Topic starter
ahhhh
thanks
Posted : 24/10/2016 8:21 pm
