Cadence data is key to any serious training program, and the Garmin Bike Cadence 2 Sensor is one of the cleanest designs out there. It mounts to your crank arm, and you don't need to mount anything to your frame. That keeps your bike looking good. The Cadence Sensor is also easy to swap between bikes, so you can get cadence info for your TT bike, your road bike, and your mountain bike without having to buy separate systems. The Cadence Sensor easily syncs with your Garmin Edge computer, so you can begin collecting data right away.