FWIW - I have Polar CS200Cad - HRM - wireless bike computer with cadence. The cadence part works. Sometimes. Mostly not. It hasn't worked in months, and the other day it started working again. Go figure? The HRM part has not worked in a year. I changed the batteries in all the transmitters, and the receiver, and checked them to be sure the batteries were good, but this is one gadget that just does not work correctly. When the bike computer quits I'll replace it, but as long as it still gives me speed and distance that's good enough for me.