I currently have a speed sensor on my fat bike but I've been thinking a lot. My air pressure can vary greatly, from 15 pounds on the road to 3 pounds on the snow which greatly affects the diameter of the tires and therefor the number of revolutions the sensor is counting. I do have my Edge 1000 set to auto calculate but I wonder if I would be better off just letting the GPS determine my speed.
Has anyone tested this out and can give some insight?