GPS Accuracy

Ive been reading a lot about the metal body of the F5/F5X causing the GPS issues. Does anyone actually have any actual proof to this, or is it just some sort of make believe story in their own heads?

Im sure Garmin would not have designed and built in such an obvious flaw. One that has already been used on the Fenix 3 series for years.

The tracks from my F5 are not that much worse than my F630 if I'm honest and I run through lots of forests and city areas.

Well, it's hard to proof I guess but it just makes sense... It's more a matter of deduction.

When comparing the Fenix (3 and 5) tracks with other watches (in my case I have a Fenix5 and 735xt) the other watch is (just about) always the best. Where 'the best' for me is a more stable, fluent track. I see that with my 735xt vs the F5, but also when looking at comparisons between for example the 935 and Fenix series.

While there can be a difference in gps chips, especially with older models vs newer models, this is less likely the case with for example the 935 vs the fenix5. They are released at the same time, have just about the exact same features and specs, etc. So then that leads to other differences, the housing being the biggest difference. The gps antenna is inside the housing and I can imagine a plastic material obstructing less then a stainless steel one.

And to be honest, I think Garmin just tries to maximize profit by providing watches that are satisfactory for the majority of people. When you ask 10 ppl about their gps experience with the fenix I guess 9 would be fine with it. But there are always those who delve into things and analyze to a larger extend, and demand/hope for more.

Do you have any comparisons of the F5 vs the F630 by any chance? You say 'not much worse', which in the end is worse... And definitions of 'not much' can vary as well ;)

For example with my half marathon, especially in the 2nd half the F5 performed clearly worse compared to my 735. If I didn't have the 735 I might be more satisfied with it, but now I just feel 'ok' about it.

But for us normal users proof is a tough thing, too many variables and it would take way too much time to collect enough datapoints. But hey, if 5 out of 5 tries already are consistent we can at least get a hunch right?

It's conjecture. And conjecture that assumes Garmin didn't look at the poorer performance of the F3 and test to see whether the metal bezel was compromising it before they produced the F5.

The Berlin half tracks a couple of pages back suggest the 735 does slightly better than the F5, but the 235 does noticeably worse than either of the others. N=1, 235 not on the same day, pretty hard to draw a solid conclusion beyond the F5 not being radically different in performance from the other watches.

I'd note that the F3 performance when it was first released was very poor (not as bad as the Spartan Ultra when that first came out, but very poor); it improved a lot after one or two GPS updates, but it never shook that reputation, and I think that's causing some confirmation bias when people look at the F5 tracks. I find it reassuring that Nick Yanakiev is basically happy with his F5x, because he was one of the people who was loudly disappointed with the F3.

As a postscript: I am looking forward to seeing some comparisons in gorges and steep forested slopes.

simple 5k parkrun in open and tree areas:

F630:

parkrun 25min pacer

F5:

parkrun 25min pacer

Both far from accurate and perfect tracks. But one not that much worse than the other?

FR935 is the clear winner for me, way cleaner and more stable track... But must say the F5 is pretty decent as well, just not as good as the FR935.

So yeah, for me it's the choice of looks vs precision (and looks is winning atm).

Have yet to see on in the flesh (this week normally) but I think the FR935 looks nicer actually, more "streamlined", not to mention thinner so as to be wearable under a shirt, hard to do that with an F5. But at the end of the day since I only really need it for running it might make more sense to stick with the FR235 that I've found to be very reliable and maybe splurge on the Stryd ;-)

As a runner I was originally attracted to the F5 for the new Firstbeat metrics but the FR235 already has the most useful ones I think (TE, VO2Max, Recovery) and I've found that you can get more thorough data by a combined use of HRV4Training on Android/iOS and Runalyze on the PC.

another gentle 7 mile run with my wife:

F630:

7 mile through mixed open and built-up areas

F5:

7 mile through mixed open and built-up areas

Again, both far from clean tracks.

Although I see a bit difference in elevation across the splits??

Those tracks look fine indeed, but hard to compare... (Also indeed because of the 2 different days, not an identical run as a result). The mygpsfiles.com site does help with the multiple track overlay but can't export your activities because I have no strava premium ;)

Btw, just saw the 7mile ones. Again looking fine for both overall, but I do prefer the FR630 tracks. Again, smoother, less wriggly. So yeah, the F5 is ok and well within specs imo but I just think it could be better.

That's also the case with my FR235 track on the Berlin HM, different day/different run, but that was more added as an extra indication and to compare with how that track ended up.

But this is about all we can do as normal users right, at most run a few times with 2 different watches at the same time and compare those. When looking at the HM tracks it is clear for me the 735xt performs better in the 2nd half, the F5 isn't doing bad, but the 735xt is clearly better (as much as I hoped otherwise). No bias here, just a conclusion from looking at the tracks. No there are no scientific papers underlying the claims and the results aren't being reviewed and published but that doesn't mean there is no hint towards something.

I mean, if I run in a straight line from A to B and GPS1 shows a straight line from A to B while GPS2 shows a wriggly line from A to B one can say GPS1 performs better right?

And more datapoints need to be collected for more proof, sure, but if I throw a 6 three times in a row with a dice I start to suspect something as well. Even though it IS possible to throw that 6 three times in a row. Let alone if it happens 4 or 5 times.

Heres the Parkrun:

http://www.mygpsfiles.com/app/#yhGtSgaK

and the 7+ miler:

http://www.mygpsfiles.com/app/#ytB8sD2v

for more easy comparison.

630 generally looks better from a track perspective in both cases, but not a huge difference.

The question was about "the metal body of the F5/F5X causing the GPS issues". The metal bezel (not body) causing issues is complete speculation, which was my main point. My secondary point is that, because the F3 has a bad reputation, people are looking at F5 tracks with an inbuilt prejudice - for example, when nyanakiev posted tracks from the 935 and the F5x worn on the same run round Millwall, somebody was very quick to dismiss the point where the 935 went for a swim as irrelevant compared to when the F5x went for a swim.

I hope you'll keep posting tracks, though, it's really useful for building up a picture with direct comparisons between the 5 and other devices. I'm not dismissing your views or your posts, far from it; I am saying let's not rush to judgement on whether the 5 series are good enough for most purposes. I think if the only thing which mattered at all was GPS performance, we'd probably all be buying a V800 or an Ambit 3, to the extent that I trust fellrrnr's assessments. (He gives the Leikr a 7 for 'how far did you run'; I have one and it wobbles all over the place then shorts you at U-turns, and I think that's cancelling out for him.)

ETA: 'you' is FlipStone two posts back, rather than Chimpware)