I got the Garmin Edge 500 installed for my road bike with the bontrager speed/cadence sensor. For my mountain bike, I just need speed. That is the second bike.

Online I see that some people use the GPS feature (no magnet) and others use a speed/cadence sensor for mountain bikes. I am thinking the speed sensor might be more reliable in the woods when I am mountain biking.

Is there really a big difference in the speed measurement with GPS only versus speed sensor? If speed sensor is the way to go- what ant+ unit to use? I see Garmin does not have a single speed sensor unit.

Thanks.

David

If you want to see how it runs w/o the speed/cadence sensor, just go into the menus and turn off the speed/cadence sensor.

If you want to put a speed/cadence sensor on a second bike, just go to eBay and search for: GSC-10

My GSC 10 keeps crapping out on me, so I've been running with just the GPS for a couple of months. Seems pretty good on the road, haven't tried dirt. There is an option to change the GPS track update to every second, I think this helps a lot.

I've heard of people having issues with the GSC 10, but I've been using them for years w/o problem, and currently have them on 4 bikes.