Elevation WRONG!! Wheel calculation WRONG!!... still didn't get fixed

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    Gareth Williams

    I’m not sure you should be trusting comparisons with other devices or Strava’s corrected elevations. I’ve found elevations to be notoriously inaccurate whatever I’ve been using. For instance, my wife and I would do identical rides together, both using Wahoo Elemnt Bolts, and never have distances or elevations been the same - often not even close.

    Also, I just tried “correcting” elevation data on Strava for a ride recorded using the K2 and another recorded using the Wahoo. Both were corrected by 100-200 feet. Strava rely on their base maps for elevation as far as I know. GPS data is known for being less than 100% accurate. My friend has a Garmin watch and some rides we do together do not even show that he rode with me!

    As for Climber, it wouldn’t surprise me if the issue has a similar root cause. I don’t worry about the absolute numbers and am happy seeing the overview of what is ahead of me rather than fretting about the average gradient over the next 50 yards - some of them do look wrong for sure!

    I wouldn’t go worrying too much about this stuff.

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    Joe Hoffman

    I did 52 miles this weekend (confirmed by Strava's corrected distance, and a GPS watch running at the same time), and the K2 stated 54 miles with its autocalculation.  I could understand being a little off, but 2 miles out of ~50 is a bit excessive in my opinion.

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    Brad Stoppenhagen

    The wheel calibration has been a know issue for some time.  It's really disappointing this hasn't been fixed yet.  While I appreciate the new features, there should be an "all hands on deck" effort to fix the wheel sensor calibration.

    As to the altitude, I don't know who to believe.  Metrics are all over the place when I ride with other people.

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    Edgar Karel

    I guess it is fixed in the 23-sep update. Did a ride today with auto calculation. Karoo measured 100,34 km, Strava corrected it to 100,53.
    Pretty good !

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    Simon Speed-Andrews

    My Garmin speed sensor, since the last update, has lost the ability to switch between auto and manual calculation, has this happened for anyone else?

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    Edward Scott

    @Edgar Karel - it's not fixed for me, unfortunately. I used auto-calibration yesterday and the Karoo clocked my 64.36 mile ride at 62.39 miles. I didn't look to see what it had calculated for the wheel circumference vs. my manually measured 2123mm. This is using a Powertap G3 as the speed sensor.

    No issue with elevation though, that seems fine.

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    Edgar Karel

    @Edward, did you recalculate your Karoo ride (62.39 miles) in Strava (64.36)?

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    Edward Scott

    Yes, and the planned distance on RideWithGPS was also ~64.4. You can see the ride here: https://www.strava.com/activities/6023635852 and the planned route here: https://ridewithgps.com/routes/37638103 . I took a wrong turn that added about .5 miles.

    I just checked the Karoo and it calculated the wheel circumference as 2027mm, which is obviously low. I measured my 700x25c tires at 2113mm unweighted, so the true value with me on the bike is likely a bit lower than that. The "normal" value for 25c tires is 2105mm.

    Based on the distance error after Strava correction, the true value is likely somewhere in the neighborhood of 2027 * 64.36/62.39 = 2091mm.

    I'll try the auto-calculation again next time I ride and see if it does any better - my understanding is the Karoo recalculates the circumference near the beginning of every ride. If it's still wrong I'll just set a manual value and call it a day.

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