Torque and wheel speed are measured within the hub. The information is then transmitted via digital radio frequency to a receiver mounted on the seatstay or chainstay of a bicycle which is wired to a handlebar-mounted cycle computer. The computer makes the calculations necessary to display a variety of power functions as well as all the standard cycle computer and heart rate functions. The PowerTap Standard Hub System features storage and recall for nine discrete, non-overlapping intervals. While doing an effort, you can capture the average and maximum power, speed, heart rate, and cadence as well as total time, distance, and energy expenditure. The Powertap will be built up in a Mavic Open Pro, 32 spoke, wheel. You can also upgrade to the PowerTap Pro or SL models, see product website for details. Retail Price: $800 Team Price: $733.00