I recently purchased Garmin's magnetless speed and cadence sensors to use with my FR235. While selecting "Indoor Bike" as an activity I'm getting a distance reading while using my indoor bike trainer. I don't have an option to input tire size, so how is distance calculated? I'm sure there isn't much difference with a 700c tire compared to a 27" tire, but the longer I go the greater the difference would be. Do the sensors come preset to a certain tire size?
Your Garmin probably defaults to 2096 - ~700Cx23. I'm sure you'll find a place to input the wheel size. Refer to page 6 of your 235 manual. Find the speed/cadence sensor and look under its settings. You'll need to make sure it's active and connected to make any changes.
