Originally Posted by
Seattle Forrest
I used to use older hiking GPS units and this would happen occasionally. With newer units, it doesn't happen. They've gotten pretty good at filtering the most obvious noise out of the signal. The latest Garmin units seem to use accelerometers (and even the compass) to predict where you're about to be and ignore GPS points that are wildly out of line from the predictions.
You may be right with the newest garmin edge computers. My wife's 510 seems pretty good so far. However, on the same ride at the same place I did see the same max speed glitches on three different cellphones, and my own Suunto Ambit2 GPS watch. (In my case the Suunto movescount site shows my correct speed from my speed/cadence sensor, but strava ignores that data and just uses the GPS data and reports a false max speed.) This was a rails to trails ride under some tree cover.