How to measure BB size

I need a crankset and bottom bracket for my new (but old!) frame. Do I simple measure the width of the BB shell and that’s it?

In the past, I’ve only ever replaced BBs, but this frame didn’t come with one so I’m not exactly sure.

I think so. What frame and year is it? You can google it!

Buy a Hollowtech II crankset and you get a one size fits all BB and a crankset in one easy purchase

richmtb – Member
Buy a Hollowtech II crankset and you get a one size fits all BB and a crankset in one easy purchase

Good idea that – you’ll still need to measure it for spacers and that.

Yes is the answer. Tape measure is fine. Probably 68 or 73mm. I’d guess 68 looking at it from here 😉

richmtb – Member

Buy a Hollowtech II crankset and you get a one size fits all BB and a crankset in one easy purchase

Not stricly true if its an 83mm BB?

Assuming square taper bb, then should be obvious even with rough tape measuring that it’s either a 68 or 73mm bb shell. As to what axle length you’ll need for your cranks, that’s a different matter, though 113mm is standard for a mtb triple I think…

Thanks guys – good tip about the hollowtech 2! Its a 2004 (ish) blur.