I have mine mounted on the bar. If you stay close to the stem you don't lose any hand space to speak of. I also mount it so that I can tilt it forward or backward (snug but not tight) depending on time of day and sun light. This adjusts the glare that I get at times. I don't think you can do that if you mount on the stem. I use a Cateye wireless cost me about 50 bucks. Has everything I need. Take a look at the Planet Bike computer, good price, good quality not as many features.