- Garmin’s route planner predicted a 22.17 mile ride.
- Strava reports a ride distance of 22.4 miles.
- The Garmin Edge reports 20.48 miles, nearly 10% down!
The plot above shows the recorded speed versus time according to Strava. The plot on Garmin Connect looks a lot smoother. I didn’t notice the speed reading flickering this time. I sometimes notice it dropping then recovering when I ride, but there is evidence that the display on the Edge shows a slightly smoothed speed reading.
So is it a steady error that Strava is correcting by inserting periodic large corrections, or does the recorded speed and therefore distance on the Garmin contain these drop-outs? I am using the speed/cadence sensor.
The mobile phone was connected and it’s following a course. Is there chance the Garmin could be dropping interrupts?
The wheel size is calibrated automatically. Could there be a large error for some reason? Could change in tyre pressure do it?
The comment at the bottom of this page looks interesting:
https://forums.garmin.com/showthread.php?35002-Incorrect-distance-information/page6
To quote:
Here is the ride from the 510 on Garmin Connect: http://connect.garmin.com/activity/415989278
And here is the exact same ride from an edge 800 riding right next to me: http://connect.garmin.com/activity/415994576
I’ve raised a ticket with Strava asking if they can help tell what happened.
I’ve tried unsuccessfully to raise a ticket with Garmin. Their support web site refused to allow me to select my product, even though it shows my product as registered when I look. When I try to select a product manually I get a lovely Java stack trace from their web server.
Tried reporting the error through http://www.garmin.com/uk/support/email-support/
Submitting the form results in a “Service Unavailable” report from an Apache server.
This really is turning into a case of very hard to contact customer support.