Bike Computer Summary
If you want to go fast, training is everything. Keeping an eye on your pace isn't always easy. A good bike computer is like having your own personal trainer sitting on your handlebars
(without the extra weight of course) yelling at you to speed up when you start slacking off and telling you to pace yourself when you start going too quickly. With built in heart rate monitors, you can take your workout a step further by keeping your body working in a target heart rate zone to maximize your workout.
Some key features to look out for when choosing between units are wireless links between sensors and the computer (this keeps your bike from looking like the backside of your desktop), heart rate monitors (these keep you working at a target exertion level and not just a speed), and cadence sensors (which are great for roadbikers as they make sure your rhythm is constant).Full Article