Cadance & GPS/Computers

[MartinGT]

This maybe a dumb question for some on here, but how is cadance calculated on GPS & Computers?

Is there a magnet to put on the crank arm or something?

 

[Christophe]

With the Garmin Edge 500 anyway, there's a small wireless transmitter that mounts to a chainstay, with a magnet on the crankarm.

 

[MartinGT]

Thanks, I thought as much.

 

[brianf7]

Garmin has a wireless speed and cadence sensor all together in one unit it picks up cadence from the crank and speed from rear wheel. So even when you are on the wind trainer you know your speed and how far you have gone without moving away from the TV.

The GPS will also tell you speed and distance just a switch over from one to the other.