I just finished up a build of an '04 trek 1500. I am using a campy centaur crank/bottom bracket. I read somewhere that since the seat tube was 35.0 mm I needed a 115.5 mm spindle length for my double crankset as opposed to 111. Is this true? I have a 115.5 on there now and it seems okay. How much clearance between the cranks and bb should there be?