Garmin and Strava - same info different values

thefd
thefd Posts: 1,021
edited September 2012 in Road general
I have been using a garmin 500 and upload the rides to Garmin Connect and to Strava. What is interesting is - although it is the same file and same info being uploaded to both, the info is different on both. Average speeds can vary by 0.1 of a mile, and my total mileage this year is different by 2 miles, although it is 1500 miles covered - 2 miles is nothing. But just seems weird when it is the same info going to both.

Anyone else noticed this?
2017 - Caadx
2016 - Cervelo R3
2013 - R872
2010 - Spesh Tarmac

Comments

  • The magic or rounding up?
    Expect someone to say " get a life" but it won't be me...
    left the forum March 2023
  • thefd
    thefd Posts: 1,021
    The magic or rounding up?
    Expect someone to say " get a life" but it won't be me...
    Yup some may say get a life - trust me it doesn't keep me awake at night. It was something I noticed and was interested as to why. In terms of rounding up - they both do things to the same decimal point so seems strange.
    2017 - Caadx
    2016 - Cervelo R3
    2013 - R872
    2010 - Spesh Tarmac
  • I ran Strava and Endomondo at the same time the other day, plus I have a cycle computer. All 3 had different distances etc, but they are all roughly the same so I am not that bothered. It was good that Strava and Endomondo both ran at the same time on my Iphone
  • thefd
    thefd Posts: 1,021
    I ran Strava and Endomondo at the same time the other day, plus I have a cycle computer. All 3 had different distances etc, but they are all roughly the same so I am not that bothered. It was good that Strava and Endomondo both ran at the same time on my Iphone
    That I can understand because they are both using the gps and making their own data from it. But the garmin makes the data and then the same data files goes into Strava, but the output details are different.
    2017 - Caadx
    2016 - Cervelo R3
    2013 - R872
    2010 - Spesh Tarmac
  • wongataa
    wongataa Posts: 1,001
    TheFD wrote:
    I ran Strava and Endomondo at the same time the other day, plus I have a cycle computer. All 3 had different distances etc, but they are all roughly the same so I am not that bothered. It was good that Strava and Endomondo both ran at the same time on my Iphone
    That I can understand because they are both using the gps and making their own data from it. But the garmin makes the data and then the same data files goes into Strava, but the output details are different.
    The Garmin and Strava interpret the same data in slightly different ways.
  • Average speed is based on "moving time" - The definition of 'moving time' is different between Strava and Garmin Connect. i.e. when you are stopped, after what period of no movement is considered 'stationary' (and should be removed when calculating average speed)

    The Strava average speed value will be less as you have to be stationary for longer before Strava recognises you are stopped.

    Can't remember the exact figures - I read it on the Strava help pages a while ago - but can't find it now.

    It will also differ on GPS unit, as it relies on the GPS stating there is no movement. Also sampling rates (how often GPS records position) will differ between devices. Probably explains why Strava increased the time :roll:
    Simon
  • Average speed is based on "moving time" - The definition of 'moving time' is different between Strava and Garmin Connect. i.e. when you are stopped, after what period of no movement is considered 'stationary' (and should be removed when calculating average speed)

    The Strava average speed value will be less as you have to be stationary for longer before Strava recognises you are stopped.

    Can't remember the exact figures - I read it on the Strava help pages a while ago - but can't find it now.

    It will also differ on GPS unit, as it relies on the GPS stating there is no movement. Also sampling rates (how often GPS records position) will differ between devices. Probably explains why Strava increased the time :roll:

    I tried Strava on my iphone for the first time today...always used cyclemeter up until now but thought I'd give Strava a go...

    Anyway my normal 'stopped' time on my 18 mile commute while waiting at lights etc is between 5-12 minutes...today Strava told me it was less than 2 minutes - no funking way!!! :) And it shortened by journey by a mile. And the stats were crap/non existent compared to cyclemeter...and it drained my battery far more.

    Not hating on Strava but I'll save it for special occasions I think :)
  • Average speed is based on "moving time" - The definition of 'moving time' is different between Strava and Garmin Connect. i.e. when you are stopped, after what period of no movement is considered 'stationary' (and should be removed when calculating average speed)

    The Strava average speed value will be less as you have to be stationary for longer before Strava recognises you are stopped.

    Can't remember the exact figures - I read it on the Strava help pages a while ago - but can't find it now.

    It will also differ on GPS unit, as it relies on the GPS stating there is no movement. Also sampling rates (how often GPS records position) will differ between devices. Probably explains why Strava increased the time :roll:

    I tried Strava on my iphone for the first time today...always used cyclemeter up until now but thought I'd give Strava a go...

    Anyway my normal 'stopped' time on my 18 mile commute while waiting at lights etc is between 5-12 minutes...today Strava told me it was less than 2 minutes - no funking way!!! :) And it shortened by journey by a mile. And the stats were crap/non existent compared to cyclemeter...and it drained my battery far more.

    Not hating on Strava but I'll save it for special occasions I think :)

    As they say, GIGO (http://en.wikipedia.org/wiki/Garbage_in,_garbage_out)
    It is used primarily to call attention to the fact that computers will unquestioningly process the most nonsensical of input data ("garbage in") and produce nonsensical output ("garbage out"). It was most popular in the early days of computing, but applies even more today, when powerful computers can spew out mountains of erroneous information in a short time.

    If you have poor GPS data, there is little any computer program can do to make it accurate :lol:
    Simon
  • Average speed is based on "moving time" - The definition of 'moving time' is different between Strava and Garmin Connect. i.e. when you are stopped, after what period of no movement is considered 'stationary' (and should be removed when calculating average speed)

    The Strava average speed value will be less as you have to be stationary for longer before Strava recognises you are stopped.

    Can't remember the exact figures - I read it on the Strava help pages a while ago - but can't find it now.

    It will also differ on GPS unit, as it relies on the GPS stating there is no movement. Also sampling rates (how often GPS records position) will differ between devices. Probably explains why Strava increased the time :roll:

    I tried Strava on my iphone for the first time today...always used cyclemeter up until now but thought I'd give Strava a go...

    Anyway my normal 'stopped' time on my 18 mile commute while waiting at lights etc is between 5-12 minutes...today Strava told me it was less than 2 minutes - no funking way!!! :) And it shortened by journey by a mile. And the stats were crap/non existent compared to cyclemeter...and it drained my battery far more.

    Not hating on Strava but I'll save it for special occasions I think :)

    As they say, GIGO (http://en.wikipedia.org/wiki/Garbage_in,_garbage_out)
    It is used primarily to call attention to the fact that computers will unquestioningly process the most nonsensical of input data ("garbage in") and produce nonsensical output ("garbage out"). It was most popular in the early days of computing, but applies even more today, when powerful computers can spew out mountains of erroneous information in a short time.

    If you have poor GPS data, there is little any computer program can do to make it accurate :lol:

    Very true, but some computer programs are more garbage than others ;)

    Nah, I enjoyed the whole idea of comparing yourself to others using Strava, but even accounting for the very definite 'oddities' that cyclemeter throws up now and again it is definitely better...based on one ride which is obviously all you need to do to get a fair comparision :P (ok, I'll leave this thread now :) )
  • Very true, but some computer programs are more garbage than others ;)

    Nah, I enjoyed the whole idea of comparing yourself to others using Strava, but even accounting for the very definite 'oddities' that cyclemeter throws up now and again it is definitely better...based on one ride which is obviously all you need to do to get a fair comparision :P (ok, I'll leave this thread now :) )

    There are lots of oddities with Strava. My biggest bug bear at the moment is how Strava works out you have ridden a segment. I created a couple of segments locally which incorporate decent hill(s) within a loop.... and can be ridden in either direction, so created loops CCW and CW, but with roughly the same start and end points.
    Regardless of the direction I ride, I get achievements on both segments!
    Also, a friend completely smashed one of my segments I was leading... it was only until later we realised it was only the start and end point that was the same, the bits in-between were very different!

    There are segments that people have created that are only 30 secs long, so if their GPS only records data every 5 secs, it doesn't take a rocket scientist to work out there are slight flaws with some of the data!

    That's why it's best use is to compare your own data, and to take it all with a pinch of salt. If you have (real) power data, then any flat-ish segments have more meaning, as your real effort is your power, not your speed.
    Simon
  • dabber
    dabber Posts: 1,926
    Average speed is based on "moving time" - The definition of 'moving time' is different between Strava and Garmin Connect. i.e. when you are stopped, after what period of no movement is considered 'stationary' (and should be removed when calculating average speed)

    The Strava average speed value will be less as you have to be stationary for longer before Strava recognises you are stopped.

    Can't remember the exact figures - I read it on the Strava help pages a while ago - but can't find it now.

    It will also differ on GPS unit, as it relies on the GPS stating there is no movement. Also sampling rates (how often GPS records position) will differ between devices. Probably explains why Strava increased the time :roll:

    I tried Strava on my iphone for the first time today...always used cyclemeter up until now but thought I'd give Strava a go...

    Anyway my normal 'stopped' time on my 18 mile commute while waiting at lights etc is between 5-12 minutes...today Strava told me it was less than 2 minutes - no funking way!!! :) And it shortened by journey by a mile. And the stats were crap/non existent compared to cyclemeter...and it drained my battery far more.

    Not hating on Strava but I'll save it for special occasions I think :)

    I posted this on an earlier thread on this subject.......

    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.
    “You may think that; I couldn’t possibly comment!”

    Wilier Cento Uno SR/Wilier Mortirolo/Specialized Roubaix Comp/Kona Hei Hei/Calibre Bossnut
  • cheers, that definitely explains some of the lost 'stopped' time
  • i only found it gives different calorie's burnt other than that its the same....well i think