If your bike has the "cable" that goes from your front wheel to your speedometer unit, unscrew the cap at the end at the speedometer and roll the front wheel. If the cable in the end turns, your speedometer is bad. If the cable doesn't move, unscrew the end at the wheel and look to see if the drive at the wheel turns with the wheel. To test the cable, turn one end, and the other should turn also. The cable is "square" at the ends where it will fit into the drives! Hope this helps.