Hi everyone - I want to replace the bottom bracket on my Raleigh Twenty. I'm interested in going the Shimano UN72 with Phil Wood retaining rings route. I know lots of other folks have done this before and I was wondering if someone knew the proper bb size. Currently Nashbar has this bb in sizes 70x115, 70x113, 70x107 - but the bb is also available in sizes 68x107 and 68x113.
Thanks for any advice!