Square Taper Bottom Bracket

john2002

I need a new bb, I've seen this (link below). I need a 68mm shell but not sure what spindle length I need.
what is the difference in spindle length? do some frames need longer length so the chain set clears the frame or is it to do with aligning the chain set with the rear cassette? or other reasion?

http://www.chainreactioncycles.com/gr/en/shimano-un26-square-taper-bottom-bracket/rp-prod34652

supersonic

It does depend on the chainset - what do you have?

omegas

remove it and you should find all the information you need on the body .

john2002

it was a cheap unsealed bb with no markings on it.
I'm also buying a new chain set because the sprockets are worn and also the chain set is seized on to the bottom brackets Spindale. so I was trying measure spindle with a ruler but with a 12 mm difference in spindle length my measurements could be way off. if I get the longer version 122.5mm what's the worse that will happen?
my chain set will stick out a bit further? or if i get a too short spindle the sprocket could hit the frame?

nicklouse

so if you are getting new cranks it does not matter what you have now.

BB length is crank specific if you are staying square taper.

so when you decide on the cranks see what BB you have to get for them.

or ask on here.

john2002

so what bb length will i need for this http://www.chainreactioncycles.com/shimano-m442-square-taper-chainset/rp-prod46021?

cooldad

113mm for a 50mm chainline according to this
http://techdocs.shimano.com/media/techd ... 657937.pdf

So 68x113 here
http://www.chainreactioncycles.com/shim ... -prod34652

john2002

thank you