Garmin Fenix 2

Triangla

I have a garmin Fenix 2, I am getting differing results from a running mate who uses a garmin 220.

My satellite reception on the same daily route is not consistent, sometimes I get a lock straight away. Other times it takes a while or not at all.

Anyone else running with a Fenix 2 who has similar issues?

Murph_D

No two gamins ever measure the same distance on the same run in my experience. I wouldn't worry about it. Garmin measurements are only approximate on an individual basis but total mileage would be pretty accurate on average over a number of runs.

Triangla

Cheers, I should have said the difference was a half a mile. I clocked 6.5 miles and he clocked 6, very significant difference there!

I would have understood a bit of difference.

Murph_D

Ah, well then one of them probably didn't have a sat lock at the start or lost it somewhere along the line.

Also, the 220 can operate without sat lock but is only accurate if it's calculating stride length properly. In my case it's pretty accurate (checked it on an indoor treadmill) but if set up for wrong height/weight etc might not be the case. Maybe your friend had sat reception turned off?

TheTubes

Murph_D wrote: »

Ah, well then one of them probably didn't have a sat lock at the start or lost it somewhere along the line.

I've had the 305 and 310xt and the only time I get problems is if I start a run before the device is finished locating satellites.
Do you wait for that to finish before you start a run?

I think the newer devices can cache or pre fetch sat locations.

Triangla

Yeah we both get a sat lock, press start at same time and have massive difference at the end.

As I said, a half mile difference after 6 miles which is frustrating. I'll have to do a test with an iPhone and my garmin to see how they differ.

Only other option is to head to a running track to see whose one is actually wrong!

28064212

Triangla wrote: »

Only other option is to head to a running track to see whose one is actually wrong!

You won't get an accurate recorded distance on a track. GPS does best in straight lines. Both of them will be out, and if one of them do give an accurate figure, it's more likely luck than anything else. You'd need to repeat the experiment many, many times to have any faith in the results

Also, you (probably) won't get the same distance on two different days, even with the same device. In fact, even if you had two of the same device, at the same time, it's quite likely you'd get two different measurements. Consumer-level GPS simply isn't that accurate.

Half a mile over 6 miles is on the larger side of inaccuracy, but it's certainly not unexpected. Have a look at the two activities on Garmin Connect, and I'd say you'll see a section or two where they diverge

twerg_85

My Fenix2 used to be very slow at getting satellite lock. Found a tip that worked -sync it shortly before you head out for run and it gets the lock very quickly.

As for measurements - it has consistently measured routes short - 2 HMs a 10k and a parkrun all came in 0.1 or 0.2 km short on the Garmin.

lgk

Open up the two runs in Garmin Connect and compare side by side. Zoom in on the route map, you'll see pretty soon which one is tracking more accurately.

Triangla

I've done the same 10k loop a few times and the map is pretty much identical.

I recken I did it the first time without a solid sat lock and it was cached. Now it pulls the same cached gps data each time I do the run.

There's no way the same anomalies would appear in the same places each time regardless of weather.