Cheap cycling computer if you have a old unused iphone 3G, 3GS, 4 and 4S.
Turn your iPhone into a full featured bike computer with the Wahoo Fitness Cycle Pack, which wirelessly connects your iPhone to any ANT+ bike sensor to get your speed, power and heart rate readings. Just hook it up to any type of road, mountain, e-bike or hybrid bikes and ride on!
Key Features
Use the Wahoo Bike Case for iPhone, with wireless speed and cadence sensor, to mount your iPhone to your bike's handlebars to capture your cycling data.
Have your iPhone read data from any ANT+ sensor, including bike speed and cadence, bike power and heart rate, keeping consistent track of your progress using the Wahoo Fitness App.
The Wahoo Bike Pack fits the iPhone 3G, 3GS, 4 and 4S models, giving you access to your favourite playlists, fitness Apps and real-time activity information easily.
Thanks OP.
Not clear if this comes with the ANT+ speed / cadence sensor or not. If it does it'll be a great deal.