mikee":3nrjppt3 said:theres a site somewhere that gives you the b/b size relative to the
chainset ,you might get some pointers
Only downside is that the bb length is also to do with the chain stay profile and material used. Old raleighs used recycled gas pipes that were several inchesvthick and are far more flared than something using fine chromo or ti. Also a bike with clearance for 3" tyres will have a more flared profile and wider bb than one designed for .5 inch tyres, that's why a single ring dh bike may use a 130mm bb ona 100mm width whereas a road bike with 2 rings will use a 104 on 68