How is elevation gain calculated?

[RickZ]

Have ridden Cap Corse Part 2 twice now. Both showing 19.44 miles. First time the elevation gain was 4,538 and the second time it was 4,726. This is what shows after uploading the .tcx file into Garmin Connect. Those numbers seem way too high and so how is elevation gain figured on VR rides? And I guess what is the actual elevation gain on this ride? Riding on a KICKR. Thanks for your help! ~ Rick Z.

[admin]

Elevation gain is calculated by Garmin using either it's own internal elevation data or elevation data submitted by Veloreality depending on whether you have fix elevation data checkbox active. Whatever algorithm they use is their own doing. We simply do not know how they do it and can not be responsible for it

[VeloReality Video]

In Veloreality software, you can see a accurate elevation gain for the full ride under the profile on the left side . There is also a elevation gain for a the selected part of the ride (from where you want to start if you move the slider bar until the end of the video) on the right side.

[RickZ]

Elevation gain is calculated by Garmin using either it's own internal elevation data or elevation data submitted by Veloreality depending on whether you have fix elevation data checkbox active. Whatever algorithm they use is their own doing. We simply do not know how they do it and can not be responsible for it

Where do you activate the fix elevation data checkbox?

[admin]

It is called "elev corrections". Placement depends on your preference, window size etc. Her is the example secreenshot taken on my computer (only relevant part of the screen is shown):

[Bradox78]

Here is a very explicit example regarding the "Lago d'Iseo" ride. This 25 km long ride is fairly flat.


GoldenCheetah shows the profile of this ride using the elevation data out of the resulting TCX file without any modifications.

The profile displayed by Strava, using the same TCX file, is very similar.

On the contrary, Garmin Connect (with or without "altitude corrections") shows a fanciful profile displaying climbs and descents when the road runs through a tunnel ...

[andy101]

I've noticed in Garmin connect that when diabling the elevation option, the elevation gain (top right of the stats) then shows the correct elevation gain from the tcx file, but the garmin elevation chart still shows their data (i.e. not the data in the tcx file).

I have this same issue when uploading from a Garmin Oregon device (I think it's a genefric Garmin issue as it also happens in Garmin Basecamp) - it's like they trust their inaccurate data over that coming from an external source (even garmin devices)