Originally Posted by
bwgride
Hi bikenh --
I was curious to compared grade estimation from ridewithgps and mapmyride. Try plotting your two routes in mapmyride and I think the grade estimates more closely approximate your verbal description. This is especially true for the tanglewood dr route plotted at .36 miles in distance where an upper grade of 21% is shown. Attached is the graphic. I think the accuracy of the estimate depends on the mapping source and also the length examined.
Very interesting comparison. I was guessing at the time 20-25% grade. I knew it was way over 18% as I've ridden Mt. Ascutney in VT twice and it has an extended stretch of 18% and averages just under 12%. I know what 18% looks like as I drive up the road several times a year helping out the hang glider pilots around the area. That's why I was shocked to see it rwgps come up with such a low % being shown for Tanglewood Drive. I'm not used to looking up a stretch of road like that...LMAO
Generally it doesn't really matter but when you run into instances where your going to hit big % grades climbs it can make the difference...like a couple of other people have stated. It gets worse when you think you don't have much of a climb but you come to find out in reality that you do because the map data is incorrect. I would have guessed the map data would have been the same between websites and the interface was set up differently between them. I thought they all dropped back to using Google maps.