Originally Posted by
sean.hwy
I have a gravel bike with four wheel sets. Only one wheel set has the speed sensor. My garmin 1030+ switches to gps mode when I use the wheels without the sensor.
I know it's using the speed sensor because I check it before each ride. I pickup the bike and pedal in place ( bike not moving / rear wheel spinning ) and the head unit shows speed is moving.
Yes, mine will do the same if the speed sensor is missing before I start the ride. In my case I start the ride and all is fine, then after a bit the speed on the Garmin suddenly drops to zero. It's still picking up cadence so I know the sender is working. I have to disable the sensor in the Garmin settings to get it using GPS again. As I mention above, the speed sensor still appears to be working, but the Garmin isn't picking it up. After some messing around I can usually get them talking again. It's quite frustrating.