Garmin Edge 510 erratic 'grade' readings

Yost
Yost Posts: 56
edited October 2016 in Road general
When I first bought this 18 months ago the grade was a useful feature. Then after a few months, it started to become very erratic, jumping around from for example +2.4% to -3% when the grade wasn't really changing much, thus rendering this feature fairly useless. It continued like this and is still the same now, so cannot be due to atmospheric conditions, which I have seen as a possible reason. Has anyone else had this problem and is it fixable? It would be a good function if it worked!

Comments

  • chris_bass
    chris_bass Posts: 4,913
    I could be wrong (I'm sure someone will tell me so soon) but I think gradient is calculated from GPS. If you have GPS turned off and a speed sensor paired it records elevation gain but won't display gradient.

    Does your speed jump around too?
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  • ravey1981
    ravey1981 Posts: 1,111
    Are the little holes on the bottom blocked by anything or obscured by a mount (perhaps you've changed mount etc)
  • ravey1981
    ravey1981 Posts: 1,111
    Chris Bass wrote:
    I could be wrong (I'm sure someone will tell me so soon) but I think gradient is calculated from GPS. If you have GPS turned off and a speed sensor paired it records elevation gain but won't display gradient.

    Does your speed jump around too?

    Yes sorry, the 510 has a barometric altimeter, grade is calculated by comparing samples to create a trend if that makes sense.... Altimeter needs those holes on the bottom clear to work correctly.
  • Yost
    Yost Posts: 56
    ravey1981 wrote:
    Are the little holes on the bottom blocked by anything or obscured by a mount (perhaps you've changed mount etc)

    Thanks for your reply. If it's the 2 wholes just under the micro USB port, those looks clear. I use the Garmin out front mount, which I have used since I bought the device. It's a bit strange as the grade function seemed to work properly for a few weeks/months but is now pretty much useless.