I have a new Edge 830 to replace my 820. I'm using the cadence and speed sensors from the 820 with the new 830. While riding, my speedometor seems to lock up at times, and or jump from say 16.2 to 18.5. the speed does not always indicate and move fluidly as it should. I was told by another Garmin owner that I do not need the additional speed sensor while riding outside, only for indoor computraining.
Do I need the speed sensor on my hub for outside riding?
Thank you,
Tom Renaud