If you install a "meter gear housing" from a sled with a drive shaft with 8t drive sprockets, say a 2001 mountain max, on your 9 t sprocket sled, the speedometer will be almost dead on, it will even show a little less. Mine showed 130 km/h on the speedo, and the gps showed 133 km/h) (97 venture 500). On the sx 600 with the correct "meter gear housing", it showed 136 on gps, while the speedo was up to 145.