I've got a pair of answer alumilite cranks, on a 113 bottom bracket, as recommended by answer. this width was obtained when I asked them what size bottom bracket would give me a 42cm chain line. well this weekend I finally got a chance to put my new wheels on, put the cogs on the wheel, slapped the chain on, spun the cranks, only to release some of the nasty noises ever, creeks and cracks. I pulled out the tape measure to check the front chain ring, to find it 50cm off center. 8 ding dong centimeters off. So here's where I show my stupidity....

Knowing that I need to pull the chainring in 8cm, what width bottom bracket do I need? I remember seeing the way of figuring it out on sheldon brown's site, but after searching through there for a few hours last night I came up with nothing. my assumption is to double the amount off, and subtract it from what I currently have, 113 - (8 x 2) = 97. But I don't beleive there to be a 97cm bottom bracket. or do I only subtract 8 from 113, leaving me with 105, which would allow me to go with an easily found 107.

damn bottom brackets, one of those things I just can't figure out by just fidling with it...