I have a 07 WR 450 it seems that the speedo may be correct at low speed but then it seems to me that the higher it registers the farther off it is. I have stock gearing, air box mods, jetted correctly, wires dissconnected and ais and pea shooter removed. When following a cage in a 30 mph zone it reads about 30 mph when I get out on my own on the back roads and open it up it seems to climb up to the 80s real quick. it also seems like I am doing well over the 89mph that I saw just shortly before the curves and washboard bumps showed up. At that point it was still pulling a little i think. I have seen over 80 on my other bikes in this strech, but this seems much faster.