Help me understand bottom brackets

kowalski [quote]Hovis Brown [quote]ffub Okay I'm kind of baffled by the whole matching up bottom brackets to cranks. I'm thinking of getting the Stronglights Roberto is selling for a pub bike. What bottom bracket am I after? Square tapered I gather but for a 42mm chainline do I want 103mm, 107mm?

"Compatible with JIS Taper bottom bracket with 107mm e.g. JP400 or JPSPB"

from the ribble site.[/quote]

Not so fast my wholemeal friend.

Check the Hubjub blog ici:

http://www.hubjub.co.uk/blog/5oct.htm[/quote]

I actually emailed them after seeing this on their Stronglight page:

Stronglight claim a 107mm JIS BB will give a 'true' 42mm chainline. That wasn't our experience, but, if you ride a 120-spaced bike, you will likely have an easier time dialling in a track crank like this than you would a repurposed singlespeed set.