Strava sync and elevation

[mvonweis]

Hi,

I am using a Charge 2 to record bike rides using "connected GPS", and this automatically syncs to Strava. I'm also using a GPS bike computer to log the same trails that is not connected to Strava. Both records show the same elevation gain within a few percent, and when I ride with friends they also get similar values. However when checking the ride in Strava, it doubles or even triples the elevation gain. This happens every time. Some examples:

• Fitbit 314 m, Bike 322 m, Strava 668 m
• Fitbit 224 m, Bike 258 m, Strava 446 m
• Fitbit 234 m, Bike 234 m, friend 288 m, Strava 683 m

What gives?

Cheers,

--Martin

[Rich_Laue]

Hello @mvonweis I'm not sure what is happening and suggest asking Strava to look into it.. They will be able to see what is happenning. 

do you sync the tracker before you stop the tracking? This is needed to send your heart data to strava. 

[mvonweis]

Hi,

Thanks, I'll check with Strava and see if they can do something.

No, I don't sync before I stop tracking. The heart rate shows up in Strava anyway.

Cheers,

--Martin

[mvonweis]

As it turns out, this is a feature in Strava. When data is transferred from Fitbit to Strava, they either don't receive the barometric height curves or simply ignore them. But they don't trust the GPS track either, so they try to standardize the results. Apparently this works fine if there is a high-quality base map available or at least a statistically useful number of workouts. Unfortunately the base map for my home area is of low quality, and so the "corrections" are abysmal. I've raised this as a bug with Strava and requested that they omit or disregard the recalculation if the base map is not good enough.

--Martin