Major Ascent Issues

With the last few updates I am getting major elevation ascent issues.  I am in 10.0 beta and today ran a 15 mile trail run and the 6X Pro Sapphire calculated 2300 feet of elevation gain.  When I got home and looked at it and felt it seemed to high so I used Stravas elevation correction and it changed to 1300 ft and after distance correction it added close to a mile.  

Has anyone else have issues with ascent being too much lately?  

How accurate is Stravas correction?

  • .12 miles for 12 miles is 1% error in distance, so thats not too bad. Still need to work out why so large differences between the two though... sounds like GPS smoothing gone awol

  • What do the elevation plots look like - do they differ in what they consider the initial point for example?

  • As an aside, I tend to find they all bloody disagree at times. My worst discrepancy is for the Gower 50miler where Garmin says 2000m and Strava says 1800m

    As they both smooth the data, you're going to see discrepancies between the two. For most of my runs I see very little difference, but for the more... upy downy ones or the more .. chaotic ones ...

    And then Runalyze adds more into the mix. It seems the greater the elevation gain, the greater the differing GPS smoothing algorithms disagree

    See what GC says in it's route planner, see what Strava says in their route planner. I guess even the route planners will differ. But you are seeing larger discrepancies than normal, are you a fell runner lol :)

  • Just done an experiment

    Did a 17K route in strava.... it said 586m ascent
    Imported into Basecamp - it said 596m

    Imported in Garmin Connect - it said 584m
    Plotaroute says 572m

    Yeah, this is a smoothing and DEM issue, which I guess trail runners will see more of as we tend to do more ... complex routes.

    I'd say take the one you trust most!

    Try planning your route and comparing - this may be terrain sensitive....

  • You still have your own calibration issue I guess, but it isn't helped by .....

     Strava

     Plot a Route

     Basecamp

     Connect

  • The precision of Strava elevation depends a lot on the accuracy of the GPS (which can be really good but also quite off) and on the quality of the Topo maps they use. I don't know about the second part, but I think that the GPS problem alone makes the Strava elevation really not that great as a reference. Except some specific cases when the barometer altitude has an issue with poor calibration or another problem, the watch altitude will be better. It's not perfect, but often it's really reliable, much more than any GPS based one. 

  • My own faith in Strava isn't helped by the elevation challenges, spoilt by people with dodgy altimeters who apparently do 100,00+m in 5 runs :) So I tend to use Strava as just a backup datastore

  • I was happy for 2 weeks only - problem reocurred yesterday