I know that many of us have moaned the issues with Garmin and its accuracy on tabulating climbing, etc. Using MotionBased and the adjustment features, I've found the results to be surprisingly accurate.

But a new problem emerges:

On this ride, you'll see a big dip at 7.5 miles and 52.5 miles:

http://trail.motionbased.com/trail/i...kValue=7872610

This perplexed me, because, while I was at the beach and knew I was "low"...I never felt that I was 25 feet below sea level (and protected by Dunes). So using the analyzer, I determined that:
  • this was a bridge crossing over the Perdido Bay Pass
  • while I was on a bridge and my Garmin registered an altititude of 66 feet,
  • MotionBased registered the topography which is the depth of the waterway under the bridge I was crossing!


So, the Garmin was accurate, but the MotionBased adjustments followed the contours and not the road/bridge elevation!

Any of you who ride in the mountains notice anything like this when you cross over a bridge?