Originally Posted by gregf83

Something doesn't sound right there. The newer units, including the 520, maintain a pool of devices and will pair with whatever devices are on your bike. Unless you're somehow turning on two powermeters at the same time the 520 should just pair up with the first one it hears. I have two bikes with powermeters and speed/cadence sensors and just get on and ride. I don't select specific devices for a particular bike.