You can add cycling-specific training data to your Garmin GPS or sports watch with the Garmin Speed / Cadence sensor GSC10 for bikes. This Garmin bike accessory measures and reports your pedal stroke per minute, providing you with valuable training feedback and helping you to set and maintain your pace while training or racing. The wireless sensor attaches to your bicycle and transmits data directly to your Garmin device. The list of compatible units includes popular Oregon, Colorado, Montana, Edge, Foretrex and Forerunner devices.