Fitness hardware company Wahoo has just announced a new Bluetooth 4.0 accessory that will let cyclists track their speed and pedaling rhythm on the iPhone. The three-piece BlueSC includes a main hub for the bike frame and two magnets: one for the wheel and one that goes just outside the pedal crank. As each magnet moves, the hub tracks its rotations and sends them to the existing Wahoo iPhone app. So far, Engadget has seen a working prototype that's apparently very lightweight, but Wahoo isn't releasing specific hardware details or information about pricing and release dates.

Wahoo has already released several bike accessories, including a sensor that tracks the same information as the BlueSC. That sensor, however, used ANT+ rather than Bluetooth for connection, so reading data on an iPhone required an extra product. The current sensor sells for $39.99, but we imagine BlueSC, like the BlueHR heart rate sensor, will go for a bit more.