I bought my Edge 800 and GSC-10 sensor just under two years ago. The GSC-10 was working fine, apart from odd cadence spikes (>200 rpm) on my trips (XC biking mostly). Then a couple of months ago, I noticed the cadance reading wasn't displaying at all and my speed was being calculated from GPS. I tried to reset it by holding the button and turning the wheel/crank, which seemed to fix it initially, but now I get strange cadence readings; it will sit at 0, then suddenly jump to the actual reading, then back to 0 again. I haven't got it overly wet and all the sensors are lined up correctly. Could it be a battery problem?
Thanks for your help.