Strava and Garmin Connect

Gazzaputt
Gazzaputt Posts: 3,227
edited July 2012 in The bottom bracket
Anyone tell me why Strava and Garmin Connect differ in the average stats when uploading a ride?

Strava is always lower in average speed etc.

Comments

  • Anonymous
    Anonymous Posts: 79,667
    Gazzaputt wrote:
    Anyone tell me why Strava and Garmin Connect differ in the average stats when uploading a ride?

    Strava is always lower in average speed etc.

    Strava is more accurate, :wink:
  • dabber
    dabber Posts: 1,926
    Strava uses the following criteria to calculate stopped time.


    Strava considers a point "not moving" if your speed is less than 0.3 meters/sec (0.67 mph), but we don't start accumulating resting time unless you're "not moving" for at least 15 seconds.


    I have a Holux GPSport 260 Pro. I recently stopped to help a rider who had crashed on a downhill in front of me.

    I was actually stopped for over 2 minutes. Strava did not fully record this stopped time as the gpx file I uploaded from Holux showed a small ripple in the speed even though the bike was laying stationary on ground at the time.
    I don't know if all gps devices that measure speed via the gps function do something similar but the end result for me is that Strava shows a slower moving average speed than the software provided by Holux does. I have queried this with Strava and they are looking at the problem. The definition of the stopped time above is directly from Strava.
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  • Gazzaputt
    Gazzaputt Posts: 3,227
    Gazzaputt wrote:
    Anyone tell me why Strava and Garmin Connect differ in the average stats when uploading a ride?

    Strava is always lower in average speed etc.

    Strava is more accurate, :wink:

    Why is it more accurate?
  • willhub
    willhub Posts: 821
    It's less accurate.

    If you've got auto pause on, then your average speed on the Garmin is your moving speed and is not inaccurate. Strava is taking the data from your Garmin device and then pissing about with it, faffing with it and messing it up.

    The only way to get Strava to be accurate is to do a none stop ride, if someone has the exact same average speed on Strava, and the same on Garmin Connect, it means two things:

    Either auto pause is turned off
    They jump red lights (so no stopping time)
  • slowbike
    slowbike Posts: 8,498
    willhub wrote:
    The only way to get Strava to be accurate is to do a none stop ride, if someone has the exact same average speed on Strava, and the same on Garmin Connect, it means two things:

    Either auto pause is turned off
    They jump red lights (so no stopping time)

    Or auto pause is turned on but they didn't need to stop because there are no lights on the journey ...

    What is "average speed" anyway ? It's the distance divided by time for a journey...

    If you're slowing down to stop should that be counted?
    What about before you're "up to speed"?
    What if your ride has some obstacles in that slow you down anyway?
    What if you come across another rider or walker that temporarily blocks your path?

    Should recovery time be counted in your average speed calc -say a climb that you have to stop 1/2way up - but is different to doing 1/2 the climb followed by a descent during which you can recover ...

    If you want to manipulate your figures further why don't you measure the distance/time but only whilst pedalling ... even then you skew the stats by turning over with no pressure on a descent ...

    It all goes to show that in isolation, average speed comparisons are more or less meaningless.
  • Slowbike wrote:
    a climb that you have to stop 1/2way up

    :?: :!: :?: :!: anyone that has to do this is a wimp :P

    I think everyone has their own version of average speed, but provided you only compare your data against your own previous data then there's not an issue. With Strava, surely the only interesting bit is comparing segments, most of which don't contain any bits where you'd be stopped so you get a true average anyway.
  • willhub
    willhub Posts: 821
    Check this, it appears mt new HTC One X deffo is more accurate than my HTC Sensation.

    Could the speed differences in the ride and segments be down to the stop sections, notice how on the Edge 800 the majority of dips to 0 actually hit the bottom, but on the One X don't.

    Could that be why?

    http://app.strava.com/rides/12301106 (OneX)
    http://app.strava.com/rides/12302635 (Garmin)