Syncing activities from Adventurer to Strava - Elevation gain wrong

NicolaQ Registered Users Posts: 1
New Traveler
edited January 24 in TomTom Sports

I've noticed that every activity that involves elevation gain (bike, running, trail running etc) that I sync from the Adventurer to Strava (via TT MySports) gets recalculated by Strava, like if the Adventurer hadn't a barometric altimeter!
Problem is that, while the Adventurer is pretty precise (I could compare it to some other bike GPS+barometer computer), when data is recalculated by Strava, elevation gain gets completely off, always increased by almost 20%.
Now, I know that Strava does recalculate elevation gain if data does not come from a barometric device (and I agree with this policy), but, considering that our Adventurer is indeed barometric, why would Strava not recognize it? Possible ways to change this?

Thanks a lot for your help. I know this problem may not seem so much of an issue, but for people like me who use Strava as their training diary this issue turns out to be pretty annoying.



  • tfarabaugh
    tfarabaugh Posts: 16,973
    Unfortunately, this is mostly a Strava issue. They recalculate all data, not just elevation, so they also change the distance, paused time, etc., based on their own analysis of the GPS. They are taking the elevation according to the GPS points and looking them up in a digital elevation model and ignoring the watch data. Talking to some of the TT developers, they have asked Strava to change this policy to accept watch data but Strava has not so far (they seem to do it for Garmin devices, but TT is a fairly small player in the market and doesn't really have much leverage unfortunately). I understand why Strava does it, as there is a competitive element with the leaderboards and they want everyone on a common playing field, but I agree it is fairly annoying. However, I have found that Strava is generally pretty close to the watch numbers in many cases (at least where I run).

    Also bear in mind that the watch, using a barometric altimeter, is capturing all elevation changes, even immaterial ones, that Strava is factoring out. You may be going down a seemingly flat road but it may be fluctuating up and down a foot or so every so often. All that immaterial elevation gain is going to add up. Strava ignores this as they are looking at the climbs, but TT doesn't, as they are looking at real elevation data. Also the barometer is impacted by weather, usage conditions and wear and tear (if the port gets blocked with sweat for instance) so that will impact the results. Put all this together and in some cases, Strava may actually be the more accurate number.

    I hope this helped answer your question. If so, please mark it as a solution so others can look for it if they have the same question.
  • Diederik Hamelink
    Diederik Hamelink Registered Users Posts: 2
    Apprentice Seeker
    Strava seem to offer a solution for devices with barometric altimeter to change the behaviour and use the altitude data as provided, Tomtom would need to add “with barometer” to the end of the creator name in the track data synchronized to strava. For example, TCX format would include something like:
    <Creator xsi:type="Device_t">
    <Name>TomTom GPS Sport Watch with barometer</Name>
    and the GPX format should have an updated creator like:
    <gpx version="1.1" creator="TomTom.2016 with barometer" ... >

    See section 'Device and elevation data' in the API documentation: .

    Tomtom: is it possible to add this to the creator name for all track data created with devices with barometric altimeters like the Tomtom Adventurer?.
  • Stuart McDonald
    Stuart McDonald Registered Users Posts: 759
    Exalted Navigator
    Hi. Thanks for that. In my communications with Strava they never mentioned this. I've raised a ticket on the back-end to look into this.
  • Diederik Hamelink
    Diederik Hamelink Registered Users Posts: 2
    Apprentice Seeker
    Hi Stuart,
    That's great!, please keep us updated on any developments.

    Thanks and regards,
  • i-zero
    i-zero Registered Users Posts: 56
    Master Explorer
    Note to myself. This is helpful. Thx
  • memphis_ESP
    memphis_ESP Registered Users Posts: 11
    Outstanding Explorer
    I think that is better this way. Every body have the same elevation gain in spite of to use differents GPS.
  • neldiogo
    neldiogo Registered Users Posts: 18
    Outstanding Explorer
    Something has changed since 12-Oct because now all activities synced to Strava have the Elevation (?) link to correct the data. This is only available when Strava recognizes a watch with Barometer. The issue is that the elevation is still messed in some way because the total elevation gain is never equal. Sometimes is less and sometimes is more.
  • memphis_ESP
    memphis_ESP Registered Users Posts: 11
    Outstanding Explorer
    Yes. In my case Strava shows more elevation than after correcting. Moreover, its impossible that the GPS elevation (Barometer) is correct because you can see that in the elevation graphic.
  • neldiogo
    neldiogo Registered Users Posts: 18
    Outstanding Explorer
    Yes the graph seems to be equal to the real one from TomTom. Only the total elevation gain is not equal.
    I had the same issue initially with Garmin Fenix 3 HR but after a few weeks they solved it.

    I created a new topic with this and other stuff that doesn't work ok with Strava to see if we can get it solved from tomtom.