Strava overestimati...
 

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[Closed] Strava overestimating elevation gain?

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When I plotted the route on strava it said 2800m elevation gain in 130km, which I dismissed as the usual issue with mapping programs struggling when you pass through contours at acute angles...

But by the end of the ride, the Garmin is saying 2800m also, and that's GPS isn't it?

I'll gladly take it obviously, most ascent I've done in a while...


 
Posted : 13/05/2018 3:04 pm
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If you zoom right in on the profile you can see if it's overestimating - the line will be sort of bumpy rather than smooth.

2100m or so vertical per 100km doesn't sound out of the question depending on where you are, and whether on or off road.  I ride several loops around here (road and MTB) which would be about that much climbing, probably more.


 
Posted : 13/05/2018 3:40 pm
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But by the end of the ride, the Garmin is saying 2800m also, and that’s GPS isn’t it?

Maybe not. it depends on the model of GPS and whether or not Strava knows it uses a Barometric sensor.


 
Posted : 13/05/2018 3:41 pm
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I don't trust the barometer elevation readings on my Lezyne Super GPS as far as I can throw it, although the amount of correction by Strava after I click the button has become a lot less since the last firmware update.

Garmins with barometers don't seem to be any better, when I look at their data on local summits of known ballpark elevation, showing way higher.


 
Posted : 13/05/2018 3:48 pm
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It's an Edge 25, had assumed GPS altimeter but don't know why.

Did a quick tally of peaks and troughs on elevation profile, looks much closer to 1800m. I would be disappointed as I'm in Mallorca now and am sure I did 1800m in Fife a few weekends ago! Now suspecting the Fife figure was an overestimate too.

Ah well, so long as they're all consistently inaccurate!


 
Posted : 13/05/2018 3:54 pm
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Edge 25 doesn't have a barometric altimeter and so has to use GPS to estimate height. That's very inaccurate.


 
Posted : 13/05/2018 3:55 pm
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Strava estimates inaccurate! In other breaking news, water is wet!


 
Posted : 13/05/2018 5:34 pm
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The elevation gain/loss is the weakest thing with GPs devices. Go on a ride with half a dozen other people & your distances will all be a pretty close match. Elevation figures will be all over the place.


 
Posted : 13/05/2018 5:38 pm
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Edge 520 barometric sensor seems spot on*. I ride a similar course most days, three climbs from sea level to 360m, 300m and 360m, and a little bit of up/down in between. Garmin registers 1100m or thereabouts every time.  I can see it'd be harder to determine accuracy if your riding is more undulating, but generally it records what I'd expect from the profile.

*or it did til I broke the screen and it filled with rainwater. Now reads 20,000m no matter what!


 
Posted : 13/05/2018 11:21 pm
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Garmin 200 here, quite often (mostly) get differing climbing/descending figures on a circular route. Guess that just means the weather has changed during the ride. Doesn't Strava work it out from the map of the route rather than taking the figures straight from the GPS like Training Peaks seems to?


 
Posted : 13/05/2018 11:24 pm
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Well around here (Spain) , you could upload a ride to Strava,  click autocorrect elevation, and it'd pretty much double what you rode. I think that was down to local mapping accuracy at the time. Recently I've noticed it doesn't over correct to such a degree, so I'm assuming the mapping improved.

In other places I rode, Strava seemed to autocorrect with a bit more accuracy.


 
Posted : 13/05/2018 11:34 pm
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Strava estimates inaccurate!

(The first part of) my morning commute registers an elevation gain of 19 metres in 1.5k. The the hill I coast down to the station would suggest otherwise :).


 
Posted : 14/05/2018 12:18 am
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Barometers need calibrating, and probably a number of times in a long ride to adjust for weather pressure changes. But generally we won't do that (and is difficult to do without knowing the real altitude at fixed points). That's why a big loop from my house and back always ends up a few hundred feet different start and end. Though I calibrate the location at the start to known altitude.


 
Posted : 14/05/2018 8:57 am

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