I am putting together a swift folder as a fixed gear. I am using a 135mm surly rear hub and sugino rd cranks up front. I am trying to figure out what spindle length to get on my bottom bracket for a perfect chainline. The BB that is suggested for the cranks ( 103mm spindle) gives a chainline of 45mm, but since I am using a mountain hub I need it to be 52mm ( correct me if I am wrong). Thoughts?
I have the 130mm Surly hub with a 47.5mm chainline. I also have the Sugino RD cranks in conjunction with a Shimano UN-54 BB in 68x107, which gives me a 48mm chainline. To get a 52mm front chainline, you'll theoretically need to add 4mm on each side of a 68x107, which means a 68x115. The only unknown is the symmetrical/asymmerical factor of certain brands of bottom brackets (non-drive side of the spindle being longer than the drive side, which skews the whole measurement).