5x Plus distance accuracy

I did a little distance check this morning with my 5x Plus. MTB ride with low speeds (4-5 mph tight and twisty). Fenix 5x plus (mounted to handlebars), Garmin FR 305 (mounted to handlebars), and Strava Andriod app on my phone (in pocket). All devices allowed ample time to get solid GPS signal/sync. I split the ride up into 3 separate 'rides'. About a 1 1/2 hour total. This is in a wooded city park w/ good cell service, no buildings, just trees. First 2 'rides' had Fenix in GPS+Galileo. On 3rd 'ride' switched to GSP only.

The 305 and the phone actually were very close in total in all three 'rides' created. They almost exactly aligned. Very impressive. The Fenix, on the other hand, consistently lost close to a 1/10th of a mile every 1 mile. I mean really consistently. It did it in both GPS+Galileo and GPS only. I also noticed a big difference in distance when I first got the watch (about 2 weeks ago) compared to my phone in GPS+Glonass mode, but didn't pay too much attention to it at the time.

What is the deal with this? I don't see a issue with the Fenix tracks (had a couple weird ones w/ Glonass), but this distance thing is unacceptable to me. Could it be that the Fenix is the actual accurate one? I doubt it, but I could be wrong.

***Edit: Need more rides before coming to conclusion. Rode again (3.5 miles) and all devices were pretty close.****

0 Jan502 over 6 years ago

Could you please share with example?

0 joshtee over 6 years ago

Ok. Just did another test ride. This time all devices seemed close. Phone was a little more distance.

3.5 mile ride. Started on residential street for about 1 mile, then trails with heavy tree cover.

Android phone w/ strava app: 3.6 miles
Garmin Alpha (Dog tracker handheld): 3.52 miles
Garmin Forerunner 305: 3.52 miles
Fenix 5x plus (GPS+Galileo): 3.53 miles

Did notice the F5x's distance would start to lag behind the 305 by a few 0.01, but it would catch back up after awhile. I'll take a look at the tracks and see how they look. Maybe this morning's ride was a outlier and these devices are all pretty close. I'll keep my fingers crossed.

On a side note, since I was watching the devices more closely then normal, I noticed my HR would randomly drop off. Noticed it about 3 times throughout the ride. Using Garmin Ant+ HR monitor. I didn't see the 305 drop HR once. This is something I've noticed on the Fenix before, but this is the first time I've paid close attention to it.

0 jrodss over 6 years ago

Just curious is the watch configured to use the "smart" logging or 1s for the GPS?

0 joshtee over 6 years ago

jrodss, thanks for pointing that out. I did not know that was a option and just now found it. My watch was definitely on the "Smart" setting. I will try it on the 1 second update setting. BTW what is the Smart setting?

0 Hopjesvla over 6 years ago

ai i also missed that one, mine was also on Smart..I would be nice if you can set these settings for each activity..E.g. a short run can be on 1 sec. recordings, though for a day long hike smart would be ok (instead of setting the GPS on Ultratrack)

0 joshtee over 6 years ago

Hopjesvla, yes it would be nice if the setting was a individual setting in a 'App'. Like MTB could have different setting then 'Run'.

0 joshtee over 6 years ago

Rode this morining:

Trails with heavy tree cover. A few clear sections to open sky. Mostly slow speed tight single track.
2 'Laps' of loop
All devices given about 10 minutes to sync w/ satellites.

Lap 1:
FR305- 3.38 mile
Android phone (Strava App)- 3.35 mile
Fenix 5x plus (GPS+Galileo and 1 sec updates)- 3.27 mile

Lap 2:
FR305- 3.28 mile
Android phone- 3.38 mile
Fenix 5x plus (GPS only and 1 sec updates)- 2.93 mile

I also did a mock ride while driving home with all three devices. Split into 2 separate recordings.
#1:
FR305- 4.11 mile
Phone- 4.1 mile
Fenix 5x Plus (GPS+Glonass and 1 sec recording)- 4.12 mile

#2:
FR305- 8 mile
Phone- 7.9 mile
5x plus (GPS+Galileo)- 7.98 mile

As you can see, the only really bad result was the 2nd Lap of trail ride. The 5x Plus did really bad job w/ distance using GPS only. The first Lap (GPS+Galileo) was acceptable, but was less distance by about 1/10th of a mile for a little over 3 miles.

The driving showed no difference between devices. Exactly the same.

0 joshtee over 6 years ago

Did another ride last night.
Heavy woods with tight single track on mountain bike. 10 minute sync time before start. Rode on road with open sky for about a 1/2 mile before entering trails.

FR305- 7.23 miles
Android Phone- 7.1 miles
Fenix 5x Plus (GPS+Galileo 1 sec updates)- 6.76 miles

5x plus short a 1/2 mile from the FR305 and 1/4 mile short of phone. I had my fingers crossed.

When I do a test that has open sky (no tree cover, residential streets), the devices all seem to be very close. In heavily wooded areas, though, the 5 x plus starts to lag behind in distance. I can not say for sure that the Fenix is the inaccurate one. It might report the actual distance and the others may be wrong, I'm not sure. I think the the phone, w/ good cell service + GPS sync, is really accurate. Also, I believe the Forerunner 305 is also a accurate device and has been very consistent, in my experience.

I am pretty disappointed that the distance results seem pretty inconsistent with this Fenix watch. For the price I paid, I'd expect the device to be consistent, refined, and do the basics without issue. To me, before adding things like Pulse O2, make sure the watch does the basics flawlessly. I bought this watch without researching things like GPS accuracy thinking that in 2018 and at $800, no way could it be worse then on my 11 year old Forerunner. Hey, but at least I can take a inaccurate Pulse OX reading when I feel like it.

I really like the watch and want to find reasons to keep it. Distance accuracy is really important to me, though. Right now, I'm thinking the 5X plus isn't cutting it. If I am missing something here or if I shouldn't rely on my other devices for comparisons, please let me know. I'm looking for reasons/excuses to keep it.

0 tommays56 over 6 years ago

On a bicycle the best distance result is going to come with the Garmin when the wheel sensor that has successfully done and auto calibration is used as none of the watch’s work well in tight twisty trees

0 bluelavender over 6 years ago

Did another ride last night.
Heavy woods with tight single track on mountain bike. 10 minute sync time before start. Rode on road with open sky for about a 1/2 mile before entering trails.

FR305- 7.23 miles
Android Phone- 7.1 miles
Fenix 5x Plus (GPS+Galileo 1 sec updates)- 6.76 miles

5x plus short a 1/2 mile from the FR305 and 1/4 mile short of phone. I had my fingers crossed.

When I do a test that has open sky (no tree cover, residential streets), the devices all seem to be very close. In heavily wooded areas, though, the 5 x plus starts to lag behind in distance. I can not say for sure that the Fenix is the inaccurate one. It might report the actual distance and the others may be wrong, I'm not sure. I think the the phone, w/ good cell service + GPS sync, is really accurate. Also, I believe the Forerunner 305 is also a accurate device and has been very consistent, in my experience.

I am pretty disappointed that the distance results seem pretty inconsistent with this Fenix watch. For the price I paid, I'd expect the device to be consistent, refined, and do the basics without issue. To me, before adding things like Pulse O2, make sure the watch does the basics flawlessly. I bought this watch without researching things like GPS accuracy thinking that in 2018 and at $800, no way could it be worse then on my 11 year old Forerunner. Hey, but at least I can take a inaccurate Pulse OX reading when I feel like it.

I really like the watch and want to find reasons to keep it. Distance accuracy is really important to me, though. Right now, I'm thinking the 5X plus isn't cutting it. If I am missing something here or if I shouldn't rely on my other devices for comparisons, please let me know. I'm looking for reasons/excuses to keep it.

For best accuracy, nothing beat Polar V800 or Suunto Ambit 3 Peak. These 2 are references. Suunto 9 now come close second. For garmin, i find only forerunner 935 is worthy to be mentioned in terms of distance accuracy.