CycleOps BLE Dual Speed/Cadence Sensor $59.99
CycleOps knows that as a saavy cyclist you want to be able to see your training metrics as you ride. And, while the Powerbeam Pro Trainer may be a little out of your budget, its BLE Dual Speed/cadence sensor is compatible with any of its trainers to provide you with on-the-go information to keep your curiosity satiated.
This sensor is bluetooth enabled which means that it can transmit both speed and cadence to your smartphone or tablet as you ride. The sensor attaches to the chainstay where it picks up not only rotations of the crankset but also of the wheel. Installation is simple.
The CycleOps BLE Dual Speed/cadence sensor comes in one size, and is compatible with most standard bike frames.