Cruising above 160-165mph (indicated) extended does not work for me on the busa,too much helmet movement due to wind.Also,top speed is very hard on the busa,because my helmet has to be on the tank(then I can't see).If I raise my head 2" off the tank,I am back in the airstream and start loosing rpm's. No problems on the 12 at extended high or top speeds.I have seen 210mph (190-192 corrected) on the busa, still climbing,and 190-192 on the 12 no more left, both with a tail wind.