Elevation way off
Elevation way off
I've noticed on my last few long rides that the total amount of climbing shown at the end of my rides is radically different (much lower) than what several mapping sites indicate it should be. The sites will claim 6500+ ft. and my iAero will say something like 4200. I've done several tilt calibrations very carefully but I have a hard time believing the mapping sites could be that far off. If anything I would expect them to under report climbing due to smoothing. What's going on?
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travispape
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- Location: Durham, NC
Re: Elevation way off
Did you go over bridges? Look to see if the mapping sites are following the profile of the bridges or whatever is underneath them. Sometimes if the GPS accuracy is low as you go over the bridge, the web sites that are based on elevation surveys think that you rode down to the bottom of the ravine/reservoir/river and back up if it misses the bridge.
Re: Elevation way off
No bridges. This is happening on completely different routes too. If it were a small discrepancy I won't care, but this is huge and I'm wondering if it means my power values are way off too.
Re: Elevation way off
6500 feet of vertical in a single ride is huge!
Could you please post a ride file that shows this issue?
Elevation data is not used in power calculations.
Could you please post a ride file that shows this issue?
Elevation data is not used in power calculations.
John Hamann
Re: Elevation way off
It is my experience that many mapping sites have quite questionable elevation data. It can be bridges, tunnels, the mapping sites road follows the contour lines differently, or just plain bad data.
I consider altimeter-based elevation data to be more reliable than GPS or mapping site data. Garmin units that have an altimeter in them even default to using that data over GPS.
6500 versus 4500 feet is a significant difference, but I've seen it that bad before. I recently did a century ride that was touted at 13,000 feet of climbing (via mapping software, they even mentioned this in the claim) that was really more like 9,800 - 10,000 feet.
I've had better luck with the website ridewithgps.com for my route planning needs (versus map my ride), but it often is not aware of tunnels and I sometimes see spikes in the elevation profile that look suspicious.
John, 6500 feet is a lot for Florida of course... I can count on an average of 1000+ feet of gain per 15 miles here in western NC, and more if I want to look for it. I rode at the beach this summer and laughed about the minimal elevation gains (400 feet over 60 miles, all of it bridges over bays), but I'll take my hills any day. When it is flat, it feels like it is uphill the whole way!
I consider altimeter-based elevation data to be more reliable than GPS or mapping site data. Garmin units that have an altimeter in them even default to using that data over GPS.
6500 versus 4500 feet is a significant difference, but I've seen it that bad before. I recently did a century ride that was touted at 13,000 feet of climbing (via mapping software, they even mentioned this in the claim) that was really more like 9,800 - 10,000 feet.
I've had better luck with the website ridewithgps.com for my route planning needs (versus map my ride), but it often is not aware of tunnels and I sometimes see spikes in the elevation profile that look suspicious.
John, 6500 feet is a lot for Florida of course... I can count on an average of 1000+ feet of gain per 15 miles here in western NC, and more if I want to look for it. I rode at the beach this summer and laughed about the minimal elevation gains (400 feet over 60 miles, all of it bridges over bays), but I'll take my hills any day. When it is flat, it feels like it is uphill the whole way!