Originally Posted by
chaadster
I think I know what you're saying, but I'm pretty sure it's accurate because while the Strava file was recorded using GPS from my phone, my Garmin E500 with wheel speed sensor also recorded 59.8mph, so it was verified (more or less; it felt like 60.4mph!). I was away at training camp, and I didn't have a computer to upload from the Garmin, but I wanted the Strava report right away, which is why I was running both.
Unfortunately, speed can't change instantaneously. If you were going 60mph you should see multiple seconds at a similar speed. If you don't then it's just a glitch in the GPS. I didn't see any samples even close to 60 so I'd chalk it up as a glitch.