And the solution to a bad chainline, is a bottom bracket that is longer or shorter by the appropriate amount. Whatever your correction is, remember to double it, because the spindle sticks out to both sides. So for instance, if your chainline is 5mm too far to the right, and your current bottom bracket spindle is 115, then you need to look for a 105 (or 104 or 106); a spindle which is 10mm shorter overall, will be 5mm shorter on each side.