# Anyone else dealing with Garmin 520 drift?



## twobigwheels (Nov 24, 2014)

My 500 used to track on Strava fine until a certain point in time while on MTB.

Updated to 520 and now I am still having drift problems:madman:...any ideas?

Thanks in advance


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## Harold (Dec 23, 2003)

what is the specific problem?

share a link to an activity illustrating the problem.


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## twobigwheels (Nov 24, 2014)

Thanks
https://www.strava.com/activities/624049605


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## twobigwheels (Nov 24, 2014)

I had a ride in between these two... and it seemed to be ok

this one drifted bad at a certain location
https://www.strava.com/activities/616681263


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## Harold (Dec 23, 2003)

I wouldn't call this "drift" exactly.

You're having accuracy problems, for sure, but where your track is accurate and not accurate do not seem to correspond with time, as most people tend to mean when they talk about drift.

I tried to check Trimble Planning to see what GPS reception looked like for your area, but the site wouldn't load for me today.
https://www.trimble.com/gnssplanningonline/

It's Chicago, so terrain shouldn't be a major issue, but it did look like the place you had trouble was an area with some valleys extending northward. How deep/sheltered are those valleys? How thick is the vegetation there? Are you using GPS + GLONASS or GPS only? Have you tried a master reset?

Here's mine from yesterday. Pretty solid results. Steeper valleys than you have for sure, thick vegetation, fairly tough conditions for a GPS tracker.
https://www.strava.com/activities/622999403


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## twobigwheels (Nov 24, 2014)

I cant say valleys are real deep for Chicago,,,but it is the most extreme terrain in area (moraine valley i believe)
It should be set on GPS + Glonass (I will double check)
Besides master reset -- any other settings I should be thinking about?
Thanks for your time


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## WR304 (Jul 9, 2004)

A good test is to have the "GPS Accuracy" field showing on your Garmin Edge 520 screen as you ride.

You can then look at this field in real time to see how well the Garmin Edge 520 is working for its GPS reception. If you have screenshots enabled (from the display settings menu) you can take a few pictures to review once you get home. The screenshots are saved as .bmp picture files on the Garmin.

The higher the number in the GPS accuracy field the lower the accuracy of your track is.

These pictures show the GPS accuracy of my Garmin Edge 520 last year under tree cover:

http://forums.mtbr.com/gps-hrm-bike-computer/garmin-edge-520-a-980371-post12221471.html#post12221471

With my Garmin Edge 520 stopping moving for a short while seems to let it rapidly recover its location, dropping the GPS accuracy back down to 10ft or so.

I'd also consider the Garmin's location on your bike. I have a theory that if your body position whilst riding partially blocks the head units view of the sky that might hurt the accuracy, even if it is mounted on the handlebars. Being blocked affects accuracy with other GPS devices, such as if it was being carried in a backpack or pocket whilst recording.


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## twobigwheels (Nov 24, 2014)

WR and Harold
Thanks for your responses.
My 520 is mounted out on barfly - there is a rubber cover on it that I am taking off (along with screen saver I am leaving on).
Changed screen views around to see Accuracy and GPS bars.
Sitting inside house (5' away from closed patio door) - Accuracy saying 10' and all 5 bars. 
Set on 1 sec recording and I use a rear wheel speed sensor - I TOOK mtb BIKE OUT in driveway AND SPEED SENSOR NOT PICKING UP ON 520...I DID CHECK IT AT ONE POINT TO MAKE SURE IT WAS SYNCED - I MIGHT HAVE BEEN RUNNING SPEED ON GPS (not speed sensor)...OFF to work - i will have to check on that later


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## twobigwheels (Nov 24, 2014)

I got my speed sensor working again (GSC 10) and went thru same section of trails and I tracked good on Strava.

I have the "GPS accuracy" displayed on 520 now. In the first part of single track (where i had no problem tracking before) reading was in low 30's. Second part (where I did NOT track well) numbers wandered up into 50's.

I road out of tree cover number went down into 30's - Almost immediately after coming to a stop, # dropped down to 10


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## Harold (Dec 23, 2003)

Ok, so you've got something tied to a location that's resulting in poor reception/accuracy.

Is there a radio tower, cell tower, high tension lines, large building, ANYTHING like that nearby?


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## twobigwheels (Nov 24, 2014)

Not that I can see by sight or on google maps - just forest preserve in that area for approx. a mile in any direction. I will keep an eye out next time in area though for cell tower.

Tree cover is denser in problem area and some 180 degree turns - no 180's in non-problem area.

My main concern was tracking good enough for strava segments. After fixing speed sensor - seems to track good enough. 

Strava app on iphone tracked good - I find it hard to believe that my $150 phone tracked good and 520 by itself (no speed sensor) didn't


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## twobigwheels (Nov 24, 2014)

I THOUGHT I had problem solved...
My son took my bike out at same trails and he tracked tracked bad in one direction (would not give segments - said he wandered off course) and turned around on same trails and it tracked good,,,then lost it again. We saved his ride.

Garmin was left on whole time (we shared bikes and my 520) and I started my ride and entire ride tracked well. I checked speed sensor before and after his ride and during my own ride.

Hopefully while he is in town we will have chance to try it again.
Next time we will try:
1) My 520 and speed sensor
2) His 520 w/o speed sensor
3) Strava iphone app

See if we get any misbehavior...


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## twobigwheels (Nov 24, 2014)

I have narrowed problem down (I believe) to my 520 being paired to my Stages Power Meter.

I have been having GPS tracking problems on Strava (bad enough to pick up only approximately 25% of segments) with my new 520. I have speed sensor, 1 sec timing, auto stop off, GPS+GLonass

I tried friends 520 and set up both 520's identically (from what I can tell)

I have narrowed it down to Stages being paired to 520 giving our 520's problems.

Ride A 7/9/16:
MY 520 paired to Stages = bad tracking.
Friends 520 using GPS+Glonass Only = good tracking
Friends I-phone Strava app = good tracking

Ride B 7/10/16:
Friends 520 paired to stages = bad tracking
My 520 using GPS+Glonass only = good tracking
My I-phone Strava App = good tracking

Rides are on MTB in woods, so a person could say tree cover - But other device's track OK.


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## Harold (Dec 23, 2003)

Interesting. I agree you might be onto something. Is the battery in the Stages meter fresh? Have you contacted Stages yet?


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## twobigwheels (Nov 24, 2014)

Stages response:
"Thanks for reaching out to us. I do not know of any way that the Stages would affect the GPS/Glonass signal: it is transmitting power data using Garmin's ANT+ protocol, and any issues with tracking would be in the Garmin firmware itself. We have seen some issues with using Garmins for ANT+ power data with bluetooth enabled. Does the problem still happen when you have bluetooth disabled on the Garmin itself?

As this issue is seen across multiple 520s, and likely occurs with any ANT+ power meters, I would go ahead and contact Garmin to see if they have a suggested solution."

Garmin Forum's response led to this link about downgrading firmware:

https://forums.garmin.com/showthread.php?342443-520-Map-Course-Sluggish-Very-Slow-to-Update/page5
_My 520 was really responsive in drawing maps when I got it (eg. updating the map direction one second after a turn), but later became very sluggish as described here, I think since upgrading the firmware from 6.00 to 6.20.
It's really frustrating indeed to miss turns because of this. So I downgraded it back to 6.00 (warning: downgrades lose all your settings!) and this instantly fixed the problem, it was back to normal (fast) drawing performance.

The original complaints here far pre-date the 6.20 firmware, so now I'm not so sure anymore that it is actually related to the firmware version. Maybe the downgraded revoked some setting on the device that causes this?

Has anyone taken this to Garmin Support? Is it a known issue?_

posters response:
It's 6.20 that's the issue. Search for the post on how to down rev back to 6.00

ALSO: Bluetooth on both 520's are disabled (mine for sure, my friends=pretty sure)


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## michael9218 (Dec 17, 2006)

You may also just have a defective unit like mine. See my other post: http://forums.mtbr.com/gps-hrm-bike-computer/garmin-edge-520-a-980371-19.html#post12059304


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## michael9218 (Dec 17, 2006)

WR304 said:


> A good test is to have the "GPS Accuracy" field showing on your Garmin Edge 520 screen as you ride.


I have found that both the displayed "GPS Accuracy" and "Satellite Reception" don't tell you much. Since I have been having so many problems with my 520, I have been displaying both accuracy and reception strength on every ride. I have found no correlation to the tracking errors and reported accuracy during the ride. In fact, on the ride I posted here (http://forums.mtbr.com/gps-hrm-bike-computer/garmin-edge-520-a-980371-19.html#post12059304) the accuracy of both units was showing the same, give or a take a couple feet. Yet the results are profoundly different.

And the satellite reception bars are a joke. Mine have always displayed 5 bars, even when my unit once notified me that it had lost satellite reception! I suspect one of the coders forgot to activate the field as live and it's just displaying test data.


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## Harold (Dec 23, 2003)

michael9218 said:


> You may also just have a defective unit like mine. See my other post: http://forums.mtbr.com/gps-hrm-bike-computer/garmin-edge-520-a-980371-19.html#post12059304


That wouldn't be the first time quality control has been an issue. IIRC, shiggy had problems with several Edge 800s in a row.


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## twobigwheels (Nov 24, 2014)

michael9218 said:


> You may also just have a defective unit like mine. See my other post: http://forums.mtbr.com/gps-hrm-bike-computer/garmin-edge-520-a-980371-19.html#post12059304


I see your point.

I find it hard to believe that my friend and and I's 520's are both bad when power meters are synced to them.

THE 520's were bought from the same place in the UK - Evan's Cycles - but in slightly different points in time (2-4 weeks).

Could 520's being bought from UK make a difference?


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## twobigwheels (Nov 24, 2014)

I am going to try a new battery in my New Garmin hub mounted speed sensor - i read that someone had received a new speed sensor and it gave them problems until new battery was put in - posters logic was that it's motion activated and that it was "on" during shipping


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## michael9218 (Dec 17, 2006)

twobigwheels said:


> Could 520's being bought from UK make a difference?


Ah ha! You're on to something now...ever since the UK voted to leave the EU quality has plummeted. Why, I had fish and chips the other day at Captain D's and I swear that were greasier than normal...must be the Brexit!


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## twobigwheels (Nov 24, 2014)

*GARMIN'S RESPONSE*:

First, please make sure you have the latest software on the Edge 520.

1. plug the device into the computer
2. Open Garmin Express then click on the image of your device and check for updates.

If you have not installed Garmin Express, please click on the link below to install

Garmin Express

you may also need to clear some data from your device that may have some corruption. Please follow these steps.

*Warning - This will delete all activities so please upload them, if necessary, before continuing.
With the watch connected to the computer:
Windows PC:
On your keyboard, select the Windows key + E, this will open the file explorer
You should see the Garmin in the drive section
Double click the Garmin drive to open it
Double click the Garmin folder
Delete the Activity and New Files folders
Empty the trash on the computer
Disconnect the watch from the computer 
Restart the watch
Mac:
You should see a drive labeled Garmin the side bar within Finder under Devices
Open the device labeled Garmin
Open the Garmin folder
Drag the Activity and New Files folders to the trash
Empty the trash on the computer
Disconnect the watch from the computer
Restart the watch
After doing this, we would recommend removing your sensors then pairing them again to the Edge 520.

Is your Strave account paired to your Garmin Connect account? Are you able to view the data in Garmin Connect? Generally signing out of your Strava account then signing back in and pairing your connect account again will resolve this issue.


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## twobigwheels (Nov 24, 2014)

I made the changes Garmin suggested and put new battery in Speed Sensor. Road in same area today (only for 1hr),,,seemed to track better, only missed 1 segment at end of ride. Phone app picked up all segments...Waiting to see what Garmin says now


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## woodway (Dec 27, 2005)

A riding buddy uses a Garmin 520 for MTB rides and he tells me that turning off Glonass and using GPS only while mountain biking in heavy tree cover substantially improves his tracking. Something that is easy for you to try.


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## twobigwheels (Nov 24, 2014)

Thanks

I am working with Guru off of Garmin forum using "Binary Data Logging" to get detailed analysis of ride. (finally figured out how to do it). I should be able to go to trails tomorrow and create file

I had a friend mention to try GPS only,,,but I bought into Glonass+GPS=Better...

I will keep Glonass + GPS for tomorrow's ride to collect data (iphone app for Strava backup...)

I will keep you posted w/my findings


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## cyclism00 (Nov 25, 2014)

@twobigwheels, I had the same problem as you, also bought mine from Evans Cycles. Glad to say my issue is fixed. I got a new replacement from Garmin, no more "drift" issues. I called it- erratic. I posted several of my Strava/Garmin Connect rides in the big 520 thread.


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## yzedf (Apr 22, 2014)

Garmin was very good about replacing my 810 for drift/erratic recording issues. They made sure I had latest firmware (yes), I did the hard reset, wiped all activities and went for one 10 mile ride. Emailed them a link to the Strava activity and 2 days later I had my confirmation to get a new (refurb actually) unit.


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