Exactly how fast were you going on that descent when you blew by ten cars? Your Mavic Wintech USB Computer knows. It also knows your average speed over your ride, and your total distance. If you did some sprint intervals, it has stored that data as well. When you get home, download the data to your PC for posterity—only it might be a good idea to hide the numbers from loved ones who think you’re a speed freak. The USB Computer can track data from two different bikes as well as your home trainer.