If you want some better braking on your yamaha prebug, look no further. The disk zuma has a great caliper to begin with. If you have a 3 bolt rotor, just take yours off, install this oversize 200mm, and adapter, and reinstall. Simple. Looks killer, and stops on a dime.
This is ONLY for yamaha prebug 89-01 with 3 bolt disk front wheel.