My Strava tracked mileage is always about 10-15% lower than that tracked by a cyclometer. This is to be expected since Strava uses GPS and the cyclometer tracks actual wheel revolution. My question is whether there is a device available that would track actual wheel revolution and send it to my iPhone/Strava via Bluetooth so the tracked mileage is more accurate. Something like the magnetic pickups that cyclometers use, attached to the fork, and wireless transmits to the phone. I tried Googling but wasn’t finding much.