Abstract: A slope measuring device, suitable for use on bicycles or other vehicles. Slope measurements are made by sensing the position of a weighted disk rotating in a cylindrical chamber. The disk is hermetically sealed and it's position is electrically monitored. Damping methods prevent the disk from moving radically over rough terrain and an onboard microprocessor processes disk readings to make accurate slope calculations. The device clamps to the handle bars of a bicycle and may be battery or generator powered.