I bought a Raleigh gran sport frame and forks, which was originally fitted with a gran sport BB. When I got it it was fitted with a cheap FAG ISO BB, with an axle length of 119mm. To this I fitted a 7400 dura ace chainset, and the resulting chain line is about perfect. But I'd like to fit a better quality BB, preferably campy. But all of the ones I see on eBay and such seem to be 112mm axle. Is all of the difference between 120 and 112 seen on the drive side? Or is it split 50 50? There is about 10mm of clearance between stay and chain ring, but I don't want to mess up a chain line that works well. Did campy do any 120mm Square taper BBs?
Yes agreed Campag & Shimano have different tapers. Am surprised it did not work loose or creak like crazy, 10mm is a biggish gap (my bike with Campag double 39T is 5mm or so, what size ring are you running and where are looking to assess the chain-line?