Originally Posted by philbob57

Just note that phones have limited power sources, so you'd have to do short rides (2-3 hours?) or get an external battery. Also, the phone GPSes aren't as good as, say the Lezyne, Garmin, Polar, Wahoo versions, so your speed and distance numbers are like to be off by what I consider non-trivial amounts. You can get good speed data by using a sensor, but that won't help much with distance.