All the bar-mounted compasses that I've tried haven't worked well due to the other metal components all around it. I'm very pleased with the compass on my Garmin Edge, although it can get confused when not moving. Most Garmin Edge models give an 8-point compass, but I would prefer it if they were 16-point; on the new Edge 810, you can access an image screen from the map that shows a virtual compass so that the precise bearing is readable.