Originally Posted by
plantrob
I think I read somewhere that a powertap will override the speed sensor, but I haven't removed the magnet to see if that's true (only got my Powertap a couple weeks ago).
That's true from my experience. There is no reason to have a wheel magnet if you are using a PT wheel. I've actually stopped using the sensors on my bikes because I find the PT hub cadence (which is estimated based on pedal surges) to be close enough. If you have the sensor in place, the 500 is smart enought to use the sensor for cadence and PT hub for speed.