Bottom Brackets

[walker]

Can someone let me know how I find out what size bottom Bracket I need? I see they all come in different sizes so as not to buy the wrong one I'd need to find the size.

 

[mickle]

A measurement across the shell will confirm it as a 68mm.
Remove your cranks and measure the length of the axle from flat to flat (x).

Your BB is a 68 x (x), like a 68 x 113 for example.

Thats all you need, its not rocket science.

 

[andy_wrx]

Providing it's not covered in rust, when you get it out the old one will probably have a label on it saying what size it is