Falling out of love with my 965 and Garmin

My 965 is not doing what it says on the tin in regards the GPS, it is short by about 400m on my local 5k parkrun, I ran an 8k event this morning an it was about 800m odd short on this event, when I was standing on the start line this morning, I was waiting to start the run with the pace pro plan, it  vibrated and told me I was on course, two minutes later it vibrated and told me I was off course, I hadn’t moved more that 2m and on the start line of the route. It has become absolutely useless for pacing an all that good stuff. I have tried it on the auto GPS setting and the multi band most accurate setting, same results, I have the 3d speed and climb on the off setting. It always seemed to be short maybe 200m over 10k, but it’s got stupid town now
Anyone have the same issues or have any advise,  or could the watch be faulty? is there a way to calibrate the GPS? 

  • You aren't perhaps using a HRM-PRo/ Plus?

  • Check the sensor settings that it is  pace and distance INDOOR ONLY (I think you need the sensor connected to change it but i cant remember fully)

    If this isn't then the distance and pace is done from the HRM

    This doesn't address your on / off course issue but may address the distance issue 

  • How long do you give the watch to get a good GPS lock? Ime it isn't enough to wait for the green GPS ring. For me, it usually takes another 30 seconds to couple of minutes to get a solid lock. The way I tell if if there's a solid lock is to look at the current pace data field. If it's fluctuating wildly while I'm standing still, then I don't have a good lock. (At the same time, the map will show that I'm moving, even though I'm not.)

    So my usual procedure before a run is to first wait for the green ring, then wait for pace data field to settle down to 0:00. Before a race, this means opening the activity well before the race starts.

    If I don't wait for the pace to settle down, then I usually get unrealistic results near the start of the run (too high instant speed, too much distance.) I realize this is basically the opposite of what you're seeing tho.

  • Yes, pace and distance was on always, I changed it to indoor, I will try that, hopefully the off course was only a glitch in the matrix this time. 

    Thanks for the quick reply 

  • How do you know the GPS distance is short? Parkrun courses aren’t usually officially measured. They are usually based of a mapping app or similar.

    Have you tried running an actually know distance…maybe a 400m track…to validate?

  • Yes, I have been letting the GPS go green before I start the activity, I had noticed that sometimes my pace would be way of at the start of the run, I never looked to check if the pace was zeroed, between this an the HMR settings, hope fully,  I will have to apologise to my 965, I have a half Marathon in two weeks and a pace pro plan in place, fingers crossed these tips sort it out 

    Thanks for the reply 

  • I would make my own course on GC for a normal training run and test all this not in a race setting .