In Reply To:
In addition, if cadence is a measure of revolutions, how the hell is garmin able to pick that up by communication with a satellite?
I personally don't trust that coming from the gps, id much rather get the measurements off the actual sensor on my bike.
WTF are you talking about???
If you don't have the Cadence Sensor (which also includes a rear wheel speed sensor - like most other cycling computers), you only get speed. And, you only get that if your Garmin is getting good satellites.
If you do have the Cadence Sensor, you get speed from GPS (satellites) if your Garmin is getting good satellites, by default. However, if your Garmin loses satellites (like when you're going through a long tunnel or in very heavy tree cover), it will switch (automatically) to getting speed from the rear wheel (magnet). If you prefer, you can also program your Garmin to only use the speed data from the rear wheel sensor. (This is what you would do if you were inside on a stationary trainer, or if you wanted to extend the battery life.)
Your Garmin ALWAYS gets cadence data from the sensor (crank arm magnet) - NEVER from GPS (satellites).
Steve
Steve
"If you ain't first, you're last." Reese Bobby Talladega Nights