I have a Polar RC3GPS heart rate monitor that records, in addition to the heart rate, speed, maps my routes, altitude, target load, etc.

Earlier this month, I accidentally purchased a speed sensor that clips on to the front fork and a small magnet that clips on a spoke. I really meant to purchase the Cadence sensor. I have since added the Cadence sensor and I really like the additional information it provides.

My question is should I return the speed sensor, (it is listed as an accessory for the monitor) or is the a reason to start using the sensor rather than have the speed recorded via GPS.

I don't understand why polar recommends the speed sensor if the gps tracks speed. Thanks in advance.

Why? ask @ Polar HQ ..

ought to function the same way magnet on crank arm, sensor on the frame , chain-stay where the arm passes close.
vs magnet on the wheel sensor on the fork ..

go, go Inspector Gadget !

I used an old wired computer along with Strava. Strava is nice but not very accurate. It will measure my max speed is 26mph while this is impossible with my Trek 820 on a slight incline. My Echo computer will say my max is 16mph. I would keep the sensor.

thank you.

My intention is to ask Polar, but I wanted to get some unbiased input prior to the call....

Inspector Gadget?