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Strava segments off course problem

muntos
over 9 years ago
Not sure if already discussed:
So, today I went to a ride and I had starred I think 5 Strava segments. Only 2 of them worked from start to finish, the rest of them gave Off course during the segment and the segment screen closed without any possibility to bring it back.
This was very annoying as I didn't had the possibility to check my segment time or to know where the segment ends. Big fail on 2 segments believing that they end up but wasn't true.
I have GPS + Glonass enabled but somehow for a short period probably the 520 lost the GPS signal or got some info and decided that I'm off course (which wasn't true at all) and close the Segment screen.
Another friend with Garmin 810 happened the same thing exactly at the same time with me, but on 810 map implementation it seems that the map shows you the segment and the end of the segment with a red square and at least you know if your segment ended or not. But on 520 I didn't saw such thing in navigation screen.
So..any experiences , tricks, solutions for this problem ?
  • 0 over 9 years ago
    The segments feature is not working well on any model for the time being, and there are loads of threads on the subject.
  • 0 over 9 years ago
    i uploaded some extracted segments to my 520, about 15 in all, and they all seem to work fine when I'm riding - not following a programmed route. They give me a countdown to the start then say GO! and there's an indicator of how far ahead or behind i am in terms of time and distance. The display changes to a small map screen showing the segment plus a location indicator for me and the target I'm chasing. Switching to the gradient screen it also shows me the 2 locations of myself and the target on the graph line.
    If I go near the start of a segment but don't ride the segment, taking another turn, for example, it tells me I'm off course for the segment then after a few seconds if I don't ride any nearer, it cancels it and the unit reverts back to normal nav mode.
    Maybe you just lost GPS signal for a few secs?
  • 0 over 9 years ago
    i uploaded some extracted segments to my 520, about 15 in all, and they all seem to work fine when I'm riding - not following a programmed route. They give me a countdown to the start then say GO! and there's an indicator of how far ahead or behind i am in terms of time and distance. The display changes to a small map screen showing the segment plus a location indicator for me and the target I'm chasing. Switching to the gradient screen it also shows me the 2 locations of myself and the target on the graph line.
    If I go near the start of a segment but don't ride the segment, taking another turn, for example, it tells me I'm off course for the segment then after a few seconds if I don't ride any nearer, it cancels it and the unit reverts back to normal nav mode.
    Maybe you just lost GPS signal for a few secs?


    When it works, it works fine, just like you described. But this happened only 2 of 5, and those were in plain field which makes me think that indeed the 520 lost GPS signal for a short time.
    My friend says, and I think he's right, that Strava segments implementation is the same as the course navigation. And we seen a lots of off-course when following a course, but there isn't such a problem as after a couple of seconds the course is found again. But on the segment page if this happens bye-bye segment screen :)
    Garmin definitely needs to take care of this problem and find a solution here, maybe loosing off the threshold.
  • 0 over 9 years ago
    When you lose the segments (or the signal...) are you in a valley, hilly area, shadow of dense trees or big buildings?
  • 0 over 9 years ago
    I had exactly the same issues, I always use my sunnto watch on my rides and all the segments crossed all showed up from the watch and the 520 missed at least 5 out of the 12 segments
  • 0 over 9 years ago
    When I was using my old Garmin 800 I never ever had any issues with missing segments so its just the 520 is not playing :mad: ..... they need to sort it out sharpish !
  • 0 over 9 years ago
    Well, there seems to be another problem here, please take a look at :
    Original segment:
    http://www.strava.com/segments/2606730?filter=overall

    Segment recorded by 520:
    http://www.strava.com/activities/396203441/segments/9495760683

    It can clearly been see that the original segment has been recorded with a poor GPS device (maybe mobile), the beginning of the segment is way off the road.
    While the 520 record is much accurate. So in this case the segment off-course what triggered by comparing with the original poor registered segment.

    BUT, Strava is able to recognize the segment, so their algorithm is better than Garmin's :). The different is that Strava is doing it offline while 520 should do this real-time, so I'm not sure if anything can be done in this situation, only that Garmin to add an option to set a threshold before considering you are off-segment.
  • 0 over 9 years ago
    It can clearly been see that the original segment has been recorded with a poor GPS device (maybe mobile), the beginning of the segment is way off the road.
    While the 520 record is much accurate. So in this case the segment off-course what triggered by comparing with the original poor registered segment.

    BUT, Strava is able to recognize the segment, so their algorithm is better than Garmin's :). The different is that Strava is doing it offline while 520 should do this real-time, so I'm not sure if anything can be done in this situation, only that Garmin to add an option to set a threshold before considering you are off-segment.

    It is really the opposite: The segment and your ride clearly deviates a lot (due to the bad segment data), and shouldn't have been a match at Strava. Unfortunately, Strava has a *very* forgiving matching algorithm, and IIRC it only requires you to match about 75% of the segment for Strava to consider it a match. As long as you pass reasonably close to the start and end points of the segment, you could actually take a shortcut and still have a segment match, as long as the shortcut doesn't take you off segment for more than 75% of the recorded segment.

    This isn't to say that Garmin's algorithms are good, because they really have issues with their live segment tracking, but I really hope that they will never make their matching as forgiving as Stravas. To get proper timing info (ahead/behind) as you ride, both good segment data and good live data is a necessity.
  • 0 over 9 years ago
    It is really the opposite: The segment and your ride clearly deviates a lot (due to the bad segment data), and shouldn't have been a match at Strava. Unfortunately, Strava has a *very* forgiving matching algorithm, and IIRC it only requires you to match about 75% of the segment for Strava to consider it a match. As long as you pass reasonably close to the start and end points of the segment, you could actually take a shortcut and still have a segment match, as long as the shortcut doesn't take you off segment for more than 75% of the recorded segment.

    This isn't to say that Garmin's algorithms are good, because they really have issues with their live segment tracking, but I really hope that they will never make their matching as forgiving as Stravas. To get proper timing info (ahead/behind) as you ride, both good segment data and good live data is a necessity.


    How did you came to this conclusion? Did you looked at the original segment ? This is a segment for road bikes, the white line is a road there, you know? And the red line marking the segment is way off the road at the beginning of the segment.
  • 0 over 9 years ago
    How did you came to this conclusion? Did you looked at the original segment ? This is a segment for road bikes, the white line is a road there, you know? And the red line marking the segment is way off the road at the beginning of the segment.

    Yes, I looked at both the segment and your ride. The segment is clearly done with bad data (not following the road), while your ride data follows the road. My point is that your ride does not follow the segment, and therefore it shouldn't have been a match, but because of Stravas relaxed matching, you still get a match.