I've got a B12 myself.Can it be made to fit? Sure! Is it a good idea? NO! The clearance between to brake caliper stabilizer arm is very close to the tire already and the chain may hit the tire at times. I ride kinda hard at times, and have rubbed the chain against the stock 180-55-17 tire and noticed rub marks against the stabilizer rod. The rim is 6", designed for a 180. It may look BADDDAZZZ! but will cause problems. Stick with the 180. The engineers that designed the bike have probably forgot more than we will ever know.