bike speedos are ALWAYS WAYYYY off… my 636 would read 189… gps would let me know that it was truly only 159.9… which was more than fast enough for me, the 10r has a speedohealer, but still gps reads much lower than the speedo at top speed… ~168.7 mph… now the gsxr on the other hand is geared taller, i bet it hits close to 190 on the gps