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  1. #1
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    Strava getting stranger

    My ride today was one loop. This loop is also a single segment on Strava

    Total ride distance: 6.8 miles
    Segment: 8.3 miles

    Even with any amount of GPS inaccuracies, how can a segment be greater than the total ride? Hell, even with NO GPS the total ride can't be shorter than the segment.
    I live with fear and danger every day. And on the weekends she lets me go mountain biking.

  2. #2
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    Maybe the whoever created the segment used a device with speed/cadence sensor?
    A segment I recently rode with two devices, a garmin 800 with speed/cadence sensor and a Samsung S2 phone the garmin read 8.12km and phone 7.6km
    The segment is listed as 7.4km
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  3. #3
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    Quote Originally Posted by KevinGT View Post
    My ride today was one loop. This loop is also a single segment on Strava

    Total ride distance: 6.8 miles
    Segment: 8.3 miles

    Even with any amount of GPS inaccuracies, how can a segment be greater than the total ride? Hell, even with NO GPS the total ride can't be shorter than the segment.
    What may be the issue, is that the rider who created the segment had back tracked and thus creating that 1.5 mile delta. Which in turn would have resulted in a higher calculated avg mph compared to your actual pace. Strava is not great for loops as it won't always catch direction of ride and you need to have a clear break where the loop starts and ends.

  4. #4
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    you can easily check to see if the rider who created the segment backtracked (or overlapped the beginning and end of the loop, or something else). Go to the segment page and follow your cursor along the segment elevation profile, while watching the dot that appears on the map.

    there are a lot of possibilities. Differences in GPS accuracy would be my primary guess, but a difference of 1.5mi on such a short ride is a pretty large discrepancy. Still, it's possible if one of you used an old smartphone (very poor accuracy) to record your ride and the other used a much more accurate device. I am not sure how Strava handles speed/cad sensor data, though. Some sharing sites ignore that data, even when it's present. I know Garmin Connect uses the sensor data when reporting ride stats, at least.

    Strava's segment matching algorithm has always been wonky. Sometimes it matches you to segments you only rode a small portion of, sometimes it fails to match you to segments you rode, and so on. It does not seem odd to me that someone created a segment that at least partially used something you rode, and it matched you to it, even with the segment being longer than your ride.

  5. #5
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    checking on Strava's Knowledge base they use the speed/cadence data from the garmin devices but Iphone and Android devices using speed/cadence sensor data is ignored and use GPS-based distance calculation.
    Link How-Distance-is-Calculated explains how Strava does it, part of their explanation on their method I have copied and pasted below

    Hierarchy of Garmin Device inputs when multiple Distance data sources exist:

    What happens if you have a power tap or a GSC-10 Speed/Cadence sensor or both? When the Edge has multiple sources for the same information it uses a predetermine selection process to go with what it considers will be the most accurate source.

    If you have a Power Tap hub connected to your Gamin, it will take speed readings from the Power Tap hub above all other inputs.
    If you have a GSC-10 Speed/Cadence sensor, the Garmin will take readings from this output over the GPS-calculated distance.
    If you have neither, the Garmin will calculate distance based on GPS.
    The key is that the data from either of these sources are seamlessly incorporated into the recorded file, under the distance stream. In some cases, the speed in MPH is documented in the file also, as an extension. Regardless, each Garmin-produced file has a distance stream of data measured in accumulated meters that serves to measure total distance and speed (both max and average).


    I have seen 11% distance discrepancy comparing my wife's Samsung S3 to my 800 riding in a heavily wooded area 4.4km vs 4.9km, yours is showing 22% difference.
    Self employed picture framer, selling the odd cycle part/light as a sideline
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  6. #6
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    I'm betting the segment has a back-track, or some other indication of creator inattention.

  7. #7
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    Use Strava Customer Support, Submit A Request. They will tell you why your total ride distance is less than the displayed segment distance.
    Self employed picture framer, selling the odd cycle part/light as a sideline
    youtube / strava. Back on a bike after 25years

  8. #8
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    Or just link to the ride and we'll provide free strava data analysis. It's worth every penny...

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