I need some advice on bottom brackets and was hoping you fine people would be able to help 🙂

I have some XT octalink cranks that use a 73-113 bottom bracket. My bike originally came fitted with Deore cranks which when I upgraded to XTs I found the bottom bracket was wrong (axles too short so XT cranks hit the frame).

I now want to use the old Deore cranks on a new frame, but no longer have the old BB. Looking at CRC there are a variety of sizes but I've no idea whether I need the 118 or the 121. Other than trial and error, how can I find out???

Cheers,

Ian

EDIT: I've just checked the spec of the bike that the Deores came from and they are M540 cranks.

shirley my dear you just need to buy and 68/73 (frame dependant) 113, as that what it came with originally?
BB's are dependant on the cranksets, not the otherway round.

Sorry, I didn't make that too clear.

The bike came with Deore M540s and an unknown BB.
I replaced the M540s with XTs which needed a BB with a 113 axle, as they didn't work with the unknown one.

I now want to use the M540s on another bike but don't know what axle length BB to get for them.

Also, I may have been mistaken when I said the XT hit the frame when using the wrong BB (it was a few years ago), they may have stood too proud and not worked with the front mech.

oh ok, can't find anything relevent on the shimano tech site, so you could try reading the info on Sheldon Brown's site, off-hand it's seemingly suggesting a 113-118, so if you have a 113 that doesn't work try the 118?

http://www.sheldonbrown.com/bbsize.html#deore

Thanks for the advice. I guess my only option is to suck it and see.

Cheers

and be very careful whilst 'test' fitting (no grease or dirt), then you could try sending it back if it don't work!

hmm double post