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Garmin edge 500 speed fluctuates

converse2020converse2020 Posts: 44
edited March 2013 in Workshop

My 2 month old Garmin is playing up. Speed fluctuates from correct reading down to 0mph. I have the cadence sensor so i assumed a simple realignment of the rear wheel magnet would resolve but no such luck. In the house it works fine. Outside no good.
I tried riding today with GPS off but that made no difference.
Ended up turning off cadence sensor and then the speed reading (via GPS) was good - until I stopped at a cafe. I took the garmin in with me and the speed kept on reading - steadily rising to 40+ mph!
In the end turning off and on stopped it.

Any ideas ? - is this likely to be a faulty Garmin unit or cadence sensor or user error ??



  • amaferangaamaferanga Posts: 6,789
    Try a new battery.
    More problems but still living....
  • narbsnarbs Posts: 593
    Had exactly the same issue with mine until I changed the wheel size from auto to 2096mm (running 700x23) which sorted it. Might be worth checking what yours is showing.

    I found that the GPS readings do go a bit wild sometimes which is why I wanted to use the speed sensor.
  • Thank. Will try changing from auto and see how it works tomorrow.
  • gloomyandygloomyandy Posts: 520
    Always worth pausing things when you take a GPS unit inside
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