Two Garmin Devices, Different Data, Which do i believe?

Enduro 3 (new) Edge 530 ( 4-5 yrs old)

Enduro 3 reads 1.4 -2.0Kms more distance than the Edge (checked on several rides now because it’s bugging me)

Coincidental finding as my chest strap battery was flat one day and I wanted the HR data from a ride so wore the watch as well. Now it’s opened a can of worms because they can’t both be correct.

Your arm will move more than the head unit; are both set to record at 1 second or is Edge set at Smart or every 5 seconds?

Two Garmin Devices, Different Data, Which do i believe?

Neither?

The difference could be due to different settings on each device. The following  are prime candidates for causing different distance measurements if they are set differently.

Auto pause

3d distance

Recording interval

Which do i believe?

The one that reports the biggest number for either distance or climbing depending on what you want to show in your Strava

How long were the rides? So we get an idea of the % difference?

I expect the watch is less accurate than the head unit. It’s smaller and less well placed.

Its pretty much a miracle that gps works at the signal is weak

If you want to use your watch as just a heart monitor then set it to “Broadcast HR” and then get the head unit to pick that up. Then you’ll never know about the discrepancy

Ultimate reliability would be a magnet sensor on the wheel

And we have eliminated sitting in a cafe with your watch on with the location jumping around?

Plot the route on a mapping app or site. Onthegomap is quite quick and easy

Various different Garmin devices in our ride group.

They all give different results when it comes to distance/climbing.

What I find more amusing is that on a circular ride my watch always shows more descent that climbing.

Not sure how that works.

More modern device is likely to have better GPS chipset, maybe multi-band. Also the antenna makes a huge difference, possibly makes a larger difference.

For height i always anchor to Strava base map. Gps is really bad at altitude

My Garmin vivoactive used to think that every run I did went about 400 feet below sea level on the South Downs. It seems to have stopped doing that now thankfully.

It still takes a ridiculously long time to get a GPS signal even when standing still outside whereas the phone gets one in about 2 seconds.

I genuinely fail to understand how Garmin remain so popular

Whichever is faster/further of course.

Your phone won’t just be using GPS for location..it’ll use any phone masts/cell tower thing to help triangulate your position…

They all give different results when it comes to distance/climbing.

But how different in percentage terms?

Rode with a friend yesterday at the Golfie & Inners, both of us have Garmin watches – height on both were within 20ft (did nearly 5,500ft).

Mrs Epic and I both have the same polar watches. When we walk the dog together mine almost always registers greater distance by a few 10s of metres. Most likely cos I wander off to take a leak in a hedge along the way

But how different in percentage terms?

I’m not really interested enough to care. 😉

One mates Garmin always seems to be about 100 meters of vert behind mine until around 1000 meters then it suddenly makes up those 100 meters and more as the ride goes on.

I think he’s got a cheat code installed.

I assume mine is more accurate as I always recalibrate the height at the start of a ride and also run a hub mounted Garmin sensor linked to my watch.

But I take any results from a Garmin as an estimate…

Neither will be correct as there a certain amount of error is to be expected. However, as DickBarton said, check your settings. Smart recording mode produces wildly wrong results and auto stop means you automatically lose crucial fitness data.

Wildly wrong results is why I started using the wheel sensor.

Even with auto stop turned off it wasn’t registering some of the push up tracks due I can only guess to moving slowly while pushing a bike up under heavy tree cover.

The sensor filled in the missing data.

I’ve also got the smart setting turned off.

If you upload the gpx track from both devices into some mapping software then you should be able to spot any discrepancies where the track wanders off the one you actually rode. This can be down to poor gps signal – being under wet foliage, in a tunnel, narrow gorge, indoors and so on. Over a long ride or run, I wouldn’t expect two devices to match exactly anyway.

My old gamin 62s is more accurate than my 840 . It’s mostly the size of the antenna.

They are accurate enough mostly.

Lakes aren’t flat according to Garmin.

K always, without fail, records a shorter ride distance that I do. Both using Garmin’s – at the moment I’m on a 530 and she’s on a 130 but for quite a while we were both on 130’s.

It’s usually by a couple of km on a c35-45km ride.

Different devices aren’t really comparable because they will have different GPS chips/antenna.

I usually get more distance than those I’m riding with because I’ve gone through the settings and turned off auto-pause and changed to 1 second recording.

Coincidental finding as my chest strap battery was flat one day and I wanted the HR data from a ride so wore the watch as well. Now it’s opened a can of worms because they can’t both be correct.

I just put my watch in broadcast HR mode if using my Edge so it’s just a sensor and doesn’t record anything, means the edge is the only recording, should spank the watch battery less too I think…

If I go for a ride without a bar mounted device then I just record on the watch obviously…

As for distance travelled, does it really matter? Surely its the doing rather than the recording that is important.

Are either of them paired with a wheel speed sensor?

Are either of them paired with a wheel speed sensor?

Nope, I don’t care enough TBH, a single GPS trace will do +/- 200m is not really important to my mind. ‘Accuracy’ is an easy rabbit hole to disappear down, but you’ll know if you had a decent ride or not.

Elevation wise I tend to update the Strava entry to use their base map for my instinct as it’s altimeter is bobbins, otherwise just take the data as it comes…

It’s quite an ask to measure altitude accurately from 22000 miles above the earth’s surface particularly if you’re in tree cover. If one were worried there’s a feature in Garmin connect called ‘true-up’ that compares your route to map data.

A lot of Garmins have barometric altimeters so don’t rely on satellite data for altitude. Usually it’s more accurate. Unless moisture gets in the sensor hole, which is quite common with Edge models.

or unless there’s a weather front coming in.

For a period I rode the bike with an Edge computer and Polar (non barometer) watch.  The barometer computer was defo closer to reality (what an OS map would show as the altitude difference) when I did comparisons on known climbs.

Generally across a bit day out, it is dependent on what the software is trying to do. Barometer tends (from.my experience) to pick up the 5m here 10m there 17m somewhere else sort of undulations on roads better than once calculating from maps or just gps.

Distance- usually within 1% for me, which I think is great given its cheap consumer electronics and no calibration after manufacturing (and maybe not even when made)

Wildly wrong results is why I started using the wheel sensor.

I use a wheel sensor and get relentlessly ragged by my mates because it records about 10% longer rides than they get. It does seem excessive even if we do ride very twisty trails.

A wheel sensor is only as accurate as the circumference info you put in to the settings,  so an additional source of difference and accuracy to fret about .

I’m with cookeaa, you’re going to have some inaccuracies in any trace, elevation or distance, you won’t know where they are going to be and working it out will be a fools errand. Enjoy the view and the ever increasing distance and elevation stats on your veloviewer dashboard

Can’t you look at the GPX outputs side by side?

If you watch DCRainmaker reviews of various watches/devices, he overlays the GPX files on the same map. You can see where one device will eg cut a corner due to lower sampling frequency or gets lost temporarily due to eg a building GPS shadow. But most often the lines are uncannily close together – ie 3-4 devices all recording precisely the same route.

A wheel sensor is only as accurate as the circumference info you put it to the settings,  so an additional source of difference and accuracy to fret about .

My Garmin (a now ancient Edge 510) automatically calibrates the wheel circ based on GPS data. Perhaps this is a setting you can toggle? If so, you’re right this could be a source of error if the device ‘chooses’ to believe the wheel sensor over the GPS.

I’m going to guess that neither are to be believed if they’re anthing like my 530.

A ride I did a couple of weeks back was 32 miles and 2750′ according to my 530. Last week, the same route but shorter, with a small loop missed out (one climb, one descent) was reported as 29.7 miles and 3665′ of climbing.

Ok, so the distance makes sense but the elevation? I just given up believing what it says now. I tend to look at the route based on the elevation data in OS maps. It’s not accurate but it comes up with far more believable numbers than the Garmin.

Whichever one finds you harder, faster, stronger and better looking.

Whichever one finds you harder, faster, stronger

Mine doesn’t do music so doesn’t play Daft Punk