Incorrect Elevation Gain

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    Ali

    Hi Mark, May I know if you calibrated the elevation ahead of the ride? If so, was it on auto or manual? We suggest a manual calibration ahead of your ride.

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    Michael Tabolsky

    A ride recorded yesterday and synced to komoot that shows the problem with altitude data. Third ride in a row that goes like this.

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    Michael Tabolsky

    Given that it also calculates some crazy speeds in the middle of nothing, am I correct that the GPS is the culprit?

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    Dirk Van Roy

    I have the same issue since middle of July. These are my rides and the difference in elevation between the K2 and Strava. The Strava elevation matches data from a Sigma Rox 12.0. Before middle of July, the K2 was spot on with calculating the elevation. Two things changed since then. Software update and I started to use a Sim card to have live tracking. Calibration is on auto, but I checked the elevation level at start of the ride and it was correct. K2 always overstates (significantly):

    - 84 km - K2 2038m, Strava 715m
    - 84 km - K2 1300m, Strava 152m
    - 57 km - K2 883m, Strava 244m
    - 64 km - K2 1495m, Strava 114m
    - 64 km - K2 157m, Strava 41m

    Thanks, Dirk

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    Michael Tabolsky

    I've been advised to start from a device reset by the support. Only rode once since then but not in the hills.
    Also started to have this problem after the software update and the sim card inserted.
    More testing is needed. 🌄

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    Dirk Van Roy

    I did a short and flat ride this morning, removed the Sim card. Elevation was 58m, according to Strava it was 53m, so much closer than the 5 previous rides, although a flat one this time. Would it be the sim card having an effect on the barometer?

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    Michael Tabolsky

    Hardly on barometer but rather GPS. Assisted GPS  uses the GSM triangulation to get a faster lock IIRC.
    Here is my flat ride from this morning:
    While there are no strange peaks, there is a 10m difference in elevation between the start and the end which are in the same point.

    <name>Morning Ride</name>
    <type>1</type>
    <trkseg>
    <trkpt lat="45.5555270" lon="8.9876300">
    <ele>176.0</ele>
    <time>2021-08-12T04:24:31Z</time>
    ......... 2hrs later ....
    <trkpt lat="45.5548870" lon="8.9874890">
    <ele>164.0</ele>
    <time>2021-08-12T06:33:52Z</time>
    <extensions>


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    Michael Tabolsky


    Here is the elevation graph from the FIT file from the today's ride with something like 1300m of jumps on top of real 1600-ish. Less than before but apparently there is a problem still. Which yet pushes me to believe that the SIM card is involved. I had it in the unit today and the coverage is acceptable in the area I rode in. Thought the exact areas I suspect don't have the coverage the spikes are more evident.
    I would test yet another ride without the SIM card to make sure it is not that or a software bug before I ask for replacement and find myself with another "defective" device.

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    Lee Armstrong

    I too have had some huge differences.  What tool are you using to visualise it?

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    Michael Tabolsky

    @Lee
    https://www.gpxsee.org/

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    Lee Armstrong

    thanks, all jagged on mine too

     

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    Daniel Röper

    I also have the issue of the jagged altitude information the others have described above:

    While the elevation information from the .fit file the Karoo 2 generated amounts to 3,600m (!), Strava corrected this down to (reasonable) 585m. Following the hint from Lee Armstrong, I‘ve deactivated the SIM card for the next rides and ended up with matching Karoo 2 and Strava elevation gains.

    @Hammerhead: I think there is a real issue with the activated SIM card affecting elevation gain calculation. Even though it‘s impossible to tell for sure, I would say that this issue did not exist a few firmware releases ago. So please look into this as this harms the Karoo 2 user experience a lot.

     

    PS. Elevation gain visualiazation by gpsvisualizer.com

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    Michael Tabolsky

    Last ride before I've sent the unit for a replacement. This one without sim card and matches the theoretical elevation almost perfectly. The blue line is actual ride and the area below is the planned route. 140km ~2000m of elevation

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    Dirk Van Roy

    Michael, did HH suggest to return your device for a replacement? Please keep us updated if the new unit has the same issues or not. My elevation is still way off when using the sim. Thanks, Dirk.

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    Marcus Jahn

    Any news here? I have the same issues with too much elevation. Today a flat 30km tour around my village and 600hm on the Karoo2, Strava reports 60Hm...

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    Anna Ronkainen

    I have experienced this as well (for some reason only in Germany) and posted about this a while ago as well: https://support.hammerhead.io/hc/en-us/community/posts/5295955480475-Bug-Strange-spikes-in-altitude-data

    Got the suggestion to try turning mobile data off and it seems to produce more realistic numbers for me as well, still trying a few more options as well (turning auto-calibration off for one thing).

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    Marcus Jahn

    Thanks Anna, I live in Germany and ride with installed SIM...But last Week I made a Tour from Spain to Italy with active live tracking, same issues! I´ll try deactivate auto-calibration and compare the fit file with my Garmin Wach recordings

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    Anna Ronkainen

    Turning calibration to manual didn’t help, only mobile data off did. I do not get these weird spikes when riding in Finland with the same unit (and same SIM card), so this must be a software thing.

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    Dirk Van Roy

    I had my unit replaced and did not have these issues with the new unit. In my opnion, some units overheat from time to time with a sim card in use. See below picture of one of my rides on Strava with the old unit. You can see everytime a peak in temperature reading when the unit records high elevation gain.

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    Anna Ronkainen

    I see abrupt temperature changes in my data as well, but these are going down, not up.

    Even when the altitude gain looks okay-ish, it seems that every time the temperature changes even by a single degree because of, well, changes in ambient temperature, the altitude spikes by a metre or two, and on a longer ride these things can add up. Are there decimals missing somewhere in the calculations or something?

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    Robert Steiner

    I purchased a new Karoo 3 weeks ago and have had a problem with total elevation gain from the very start. Have already submitted several tickets, first response was to send all the data which I did (both FIT and GPX from another app so one can compare); was then told it had been fixed in the software release of last week, but issue is still there. Have now been told that it will be fixed in the next release.
    I do not use a SIM card and total gain is off between 5%-10% per 100m gain. Have seen this now in Spain and Switzerland and having done the same rides for years in CH I am absolutely confident that the Karoo is wrong. In fact one can even see it as after going over a few small "bumps" it will show an elevation gain of 2-3 meters and in reality it can't be more than 0.5-1m at the very most. 
    Sort of at a loss as ready the posts this issue seems to have been around for over 9 months now, and this is really not rocket science.

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    Vincent Lefort

    Hello there !  just bought the HH karoo2 . Same problem as described for me and my friend , i have also notice that in the calibration page my altitude was 17 meters and when i was shaking the device it was changing all the time 22 25 11 13 20 . So if its happening in a riding scenario no wonder its register way to much elevation gain . If they cant fix this issue at least they should give the option of Altitude Via GPS data instead of barometric it sound easy to do i my head ahah . 

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