Went on a ride with a friend yesterday, and was comparing our results. During the ride, he led becuase it was a route he knew. I followed and was never more than a second or two behind. But on some segments Strava is showing as much as two minutes time difference. Realise this could be due to inaccuracies in GPS recording. We both have Garmin Edge 830s that we used to record the ride. Is the accuracy really this bad or is something else going on?