Failing GNSS on Triathlon Run? Settings?

Former Member over 7 years ago

I have been testing my Fenix 5 plus for some weeks and can't say i am impressed by it, especially the Global Navigation Satellite System (GNSS) receiver.

Running and Cycling results are "ok", same as GPS only Suunto Spartan Trainer (SST) and GPS logger. (watch settings: GPS+Galileo)
Open water swimming (OWS) was/is BAD.
Last 9 months i used the SST to register a OWS route with 100% "clean" tracks and a max error of +/-3% (50+moves). This is used as reference.
The F5+ immediately produces bad tracks with "spikes" and other impossible moves (same as DCrainmakers OWS results (https://www.dcrainmaker.com/2018/07/...eekend-73.html)).
Changing the watch to GPS only seems to improve things.

However as i still have limited tracks on all types of activity i was not going to make a post until i did a triathlon yesterday.

Triathlon results:
- Swim result where "bad" but that is not the problem for now.
- T1 (similair to run, see below)
- Bike part is prefect, a 100% clean track with no visible errors
- T2 (similair to run, see below)
- Run is the problem.

The total run is false, not just some points but from start till end.
The total track looks likes its made by the new Suunto 9 FusedTrack algorithm.
In the pictures below you see the strava results of 35 other Tri-runs on the same event.
Watches uses are: Garmin Vívoactive, 910XT,920XT, 935, 735XT, Fenix 3, Fenix 5S, Fenix 5.Fenix 5X, Polar M600, TomToms, Suunto Ambits 2+3, Stava Iphone App
and ONE Fenix 5 Plus, clearly the only track that fails.

Can this be a user error?
Part of the run is parallel to the bike track where everythig during cycling was 100% ok (2 passes) but not durring the run (2 passes).

With Triathlon mode you can't set the individual GPS settings but i assume it uses the individual settings for OWS, Bike and Run. (GPS, GPS+Galileo and GPS+Galileo in my situation)

(p.s. installed the 3.21 beta: Improved Open Water Swim performance but not tested yet (multiple swims this weekend)) ciq.forums.garmin.com/.../1371970.jpg ciq.forums.garmin.com/.../1371971.jpg

0 Browner40 over 7 years ago

wow... that's not just "Bad", that is terrible!

0 kalamarios over 7 years ago

Do we know if this is really only for open-water activities?

I really want to buy one of the Plus Fenix (for the maps) but I really don't want to do Garmin's debugging, not for $800. It's simply offensive!

0 Former Member over 7 years ago

Did a 2nd Tri earlier this week and run results in Triathlon setting are still wrong.

Installed the 3.21 beta: Improved Open Water Swim performance.
All settings GPS+Galileo

Triathlon results:
- Swim result where now about the same as previous GPS only mode was. "Bad" compared to a Polar V800 or Suunto Trainer (too few fixed points)
- T1 (very short distance, ok)
- Bike part is prefect, a 100% clean track with no visible errors
- T2 (very short distance, ok)
- Run is the problem again.

As you can see the location the watch registers is depended on the running direction by al large amount.
Show is the turning point of a 2 lap route.
On lap 1 you run on the left/bottom side and return through the middle, on lap 2 you run on the right/top side and return through middle.

What can be seen is that running to the turning point is perfect, even the side of the road can be seen.
However as soon as the turn is made there is aHUGE offset (running left to right) while it should have been on the road between the other 2 lines.
This happens 2 times in row (delta t = 10 minutes).
The few buildings are low and not dense (1 or 2 levels (3-6meter))

I have never seen the issues as seen on my 1st and 2nd triathlon example on any watch i have ever used.
Looking at Strava again shows theFenix 5 plus is the only watch having problems. (40+ others)ciq.forums.garmin.com/.../1374805.png

0 Erik_vH over 6 years ago

Last weekend I also did another triathlon again. And this time I have similar results as described by BWonder.

I have set GPS to GPS only for all activities.

- Swim result: GC says 1302m , while official distance is 2500m. Funny thing is, the track looks correct. If i download the GPX file and import this into gpsies.com, it will give 2230m. For me, this would be acceptable figures.
- Bike part is perfect, at the turnaround points the side of the road is visible every time.
- Run is the problem also, it horrible. Left side Fenix 5+ , right side other athletes 935.

One remarkable thing, during the run i have checked the map a few times on the watch, at that time i was convinced that the track was displayed correctly on the watch.

---
Ok, so now we have some analysis done, is this this the official way to report issues? Or is there an official bug reporting tool? ciq.forums.garmin.com/.../1389002.png

0 Browner40 over 6 years ago

Call or email Garmin support and open a ticket. While some Garmin personnel do peruse this forum, it is not an official way to report an issue. I'm 99% sure this is a software issue, since the Forerunner 935 got the same GPS firmware update when the Fenix 5Plus was released and it broke the OWS and general GPS reliability on the forerunner in the same way that people are seeing on the Fenix 5+.