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Mileage Tracking

cwright12453
over 5 years ago

Good Evening everyone,

I have a bit of a concern/question with my new Edge 530.  The new Edge is not tracking mileage the same as my Edge 520 or my Strava apps on my phone.  Now before anyone says it, I know strava is not the greatest in terms of accuracy.  With that said though, my Edge 530 does not match up with my Edge 520.  For example, I went out mountain biking today and I knew the loop because of the elevation gain, etc would be about 13 miles.  I have tracked this many times with my 520.  My 530 on the other hand picked up 9.86 miles.  Now, I am not sure if there is a setting in the unit that is incorrect, or if there is just something wrong all together.  I am on the newest 4.10 firmware version.  I did not have the unit when it was on the older firmware, so I do not know if it was a 4.10 issue or not.

Anyone have any ideas what is going on.  If this is how the unit is going to work, I might as well do a return to Nashbar and stick with my 520.

Thanks

Chris

  • 0 over 5 years ago

    Were you riding in forrests by any chance? The new GPS chip used in the Edge 530 and Edge 830 appears to be working far less precise than previous generations under such conditions as demonstrated by the numerous reports like https://forums.garmin.com/sports-fitness/cycling/f/edge-830/170025/continued-gps-issues and https://forums.garmin.com/sports-fitness/cycling/f/edge-830/165787/poor-gps-recept-edge-830

    Verify yourself if the GPS track of your rides matches up with reality especially on corners.

    If your main concern is distance tracking you might try using a speed sensor such as https://buy.garmin.com/en-US/US/p/641221 which will track distance by counting the rotations of the wheel rather than rely on GPS tracking which as reported above cuts corners short and underreports distance under said conditions.

    Otherwise one can only hope the issues are fixable at all by a firmware update and that one is being worked on.

  • 0 over 5 years ago

    I spoke with Garmin about the issue.  They have advised returning it and swapping for a new one. 

  • 0 over 5 years ago in reply to cwright12453

    It would be good to get some comment from Garmin on the various comments raised

  • 0 over 5 years ago

    From riding with a friend who as an 810, I knew my 530 was recording about .5 km short on a 40 km ride (three days in a row). I did some reading and figured (hoped) the device had auto-calibrated my speed sensor inaccurately, because I was using the default 'Smart' data recording and went around a few corners while it was calibrating. It showed a wheel diameter on my road bike of 2076 mm.

    Today I tried to fix this by unpairing and re-pairing the sensor and letting the 530 get a good signal before riding in a straight line for 1 km with 1 sec. data recording enabled. I got 2040 mm. This would, of course, under-record by even more. I did it again and got 2094 mm!

    So I left the wheel circumference display up and rode, and watched the auto-calibrated circumference jump around from below 1900mm to over 2000mm.

    I then came home and measured the circumference as 2010 mm and entered this manually, and then measured a lap of the local park at 3.8 kms, which I know is correct from riding many laps with my old 520.

    So, I can now confirm that the 530's GPS accuracy appears to be as crap as other threads on this site suggest and that, in auto-calibrate mode, this is used to constantly recalibrate the wheel circumference, which means that, even with a speed sensor, you get the distance and speed that the (crap) GPS provides.

    The only way to get accurate distance and speed is to use a speed sensor and manually measure and enter the wheel circumference.

    I miss my 520.

  • 0 over 5 years ago in reply to Mr.Terrier

    Oh dear. I knew the Edge will recalibrate the sensors when set to auto but the jumps you describe are insane. Somewhere on this forum someone mentioned that calibration only happens when the reception is good. I think that's the problem with the new Edges (830 & 530): they always think the reception is perfect (GPS accuracy data field always shows 3m).

  • 0 over 5 years ago in reply to Mr.Terrier

    I know that the auto wheel size is a feature, but, if you have the ability to measure the wheel rollout and be absolutely sure, why wouldn’t you do it that way?

    i guess I’ve always measured wheel rollout since the 80’s, so it’s no big deal to me. I’m not saying that the GPS shouldn’t be accurate, it should, but even if it was, I’d still measure the wheel.

  • 0 over 5 years ago in reply to Tim_B_

    The reason would be accuracy. If the GPS is accurate to 3m and takes 1000m to calibrate your wheel, the accuracy is to about .5%. That degree of accuracy translates to measuring your wheel circumference to within about .5mm. I doubt I could do that.

  • 0 over 2 years ago

    I've had the same problem thats why I'm here. Yesterday went for a ride in windermere  and my garmin 530 came up 1.4 mile shorter than my mates and 800ft in elevation. As soon as they all hit strava as we all rode together you could see clearly that something amiss. Would a speed sensor really sort that out? And I've also turned auto pause off because when your mates on the same ride are coming out at 7.5 miles and yours is 6.1 you're having a laugh 

  • 0 over 2 years ago in reply to 8650133

    I can't see how turning auto-pause off will help. The distance is still the same; you just take longer to cover it so your average speed will go down. Read my original post above. It explains how a speed sensor should fix the problem. Without at sensor, the Edge uses the (crap) GPS to measure your distance. With a sensor, it doesn't.