Fenix 5 Pace Accuracy

May 7, 19 10:57

Post #1 of 17 (4378 views)

Apologies if this has been covered but I did a quick search and didn't find much. I got a Fenix 5 a few months ago and it has been a great day-to-day watch, but the current pace when running is all over the place. It seems like the average pace when I finish a run is fine but at any given moment when I look at the watch it's wrong, and could vary by a minute per mile or more within a few seconds. Kind of useless if I'm trying to run intervals or maintain a certain pace. I've tried both traditional GPS and Glonass and Glonass actually seems to be worse.

From what I've gathered on the Garmin forums, GPS accuracy on the Fenix 5 can be a little suspect, although DCR's review says it's good. I've also read that it could be the metal case, since the 935 and other plastic watches don't seem to have issues. Does anyone know if this is correct? Are there other settings I can tweak to get better pace accuracy? Or did I just buy the wrong watch?

Thanks!

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 11:10

Post #2 of 17 (4356 views)

Dgconner154 wrote:

Apologies if this has been covered but I did a quick search and didn't find much. I got a Fenix 5 a few months ago and it has been a great day-to-day watch, but the current pace when running is all over the place. It seems like the average pace when I finish a run is fine but at any given moment when I look at the watch it's wrong, and could vary by a minute per mile or more within a few seconds. Kind of useless if I'm trying to run intervals or maintain a certain pace. I've tried both traditional GPS and Glonass and Glonass actually seems to be worse.

From what I've gathered on the Garmin forums, GPS accuracy on the Fenix 5 can be a little suspect, although DCR's review says it's good. I've also read that it could be the metal case, since the 935 and other plastic watches don't seem to have issues. Does anyone know if this is correct? Are there other settings I can tweak to get better pace accuracy? Or did I just buy the wrong watch?

Thanks!

No matter the GPS watch you should not use instant pace.

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 11:24

Post #3 of 17 (4342 views)

yeah the current pace always fluctuates pretty dramatically because its taking a point like every second and then recalculating the pace based on the timestamps of the points and the distance covered between the points and then estimating what the pace would be over the course of a mile. I am not certain but it seems logical that the more points you collect, the more widely the swings in pace earlier on in the mile and then towards the end they would match the actual mile pace. Ever look at your pace graphs and notice the spikes? Its because they haven't been smoothed.

Use this link to save $5 off your USAT membership renewal:
https://membership.usatriathlon.org/...A2-BAD7-6137B629D9B7

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

philipshambrook

May 7, 19 11:32

Post #4 of 17 (4330 views)

A GPS datapoint is out by as much as +/- 15m in any direction. It follows that any pace calculation from any datapoint will vary.

While the F5 was noted for its poor GPS performance, instant pace (or instant speed) is not a good measure on any consumer GPS.

Trust me I’m a doctor!
Well, I have a PhD :-)

Re: Fenix 5 Pace Accuracy [AlyraD] [ In reply to ]

May 7, 19 11:35

Post #5 of 17 (4325 views)

Yeah that makes sense and I know the instant pace will never be perfect, but it was way more accurate on my old 1st gen Vivoactive than the F5. Just curious if the metal body of the F5 is part of the cause. Maybe I need to set the lap interval to 1/4 mile and use lap pace or something.

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 11:44

Post #6 of 17 (4294 views)

I do think youre right about the aluminum body. From what I gathered, the 935 has the same chipset as the F5 so if we work backwards the major differences would be the aluminum casing; or maybe the larger battery could be interfering? I have no clue on that though.

Use this link to save $5 off your USAT membership renewal:
https://membership.usatriathlon.org/...A2-BAD7-6137B629D9B7

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 12:06

Post #7 of 17 (4273 views)

Not using instant pace is hogwash. My 935 has FANTASTIC instant pace and I use it all. the. time. It rarely reports something out of whack. I've been using an old orange brick 310XT for the past few weeks, and it's also good- but not perfect, much worse than the 935, but still really usable.

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 12:09

Post #8 of 17 (4266 views)

Instant pace on most GPS watches suck. However, there is a super easy fix. Get a foot pod. Then, in the watch's settings for the foot pod, there is an option to tell the watch to use the pod for instantaneous pace all the time. Boom, fixed.

Re: Fenix 5 Pace Accuracy [nickwhite] [ In reply to ]

May 7, 19 12:14

Post #9 of 17 (4255 views)

nickwhite wrote:

Not using instant pace is hogwash. My 935 has FANTASTIC instant pace and I use it all. the. time. It rarely reports something out of whack. I've been using an old orange brick 310XT for the past few weeks, and it's also good- but not perfect, much worse than the 935, but still really usable.

Yeah I'm not really sure how to do tempo runs and intervals without instant pace. I know there are lots of talented runners out there who have been doing it their whole lives and can nail a specific pace by RPE or whatever, but I can't. Never really had any issues with the old Vivoactive.

Last edited by: Dgconner154: May 7, 19 12:22

Re: Fenix 5 Pace Accuracy [exxxviii] [ In reply to ]

May 7, 19 12:22

Post #10 of 17 (4238 views)

exxxviii wrote:

Instant pace on most GPS watches suck. However, there is a super easy fix. Get a foot pod. Then, in the watch's settings for the foot pod, there is an option to tell the watch to use the pod for instantaneous pace all the time. Boom, fixed.

I was hoping to avoid that since I rotate through multiple shoes but it might be my best option. I remember these GPS issues from previous Fenix versions but I thought Garmin had fixed them.

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 12:32

Post #11 of 17 (4224 views)

I do not think it is an issue unique to the F5. And, I think it is some kind of dark magic that bike GPS computers and car GPS is even in the ballpark. As noted above, if you are running an 8 minute pace, then your watch is taking a GPS calculation every 11 feet. If the error in a GPS reading is ±20 feet, then the error factor could double the distance traveled during the measurement period. Maybe car & bike GPS speed works because the error factor is smaller than the measurement period, or maybe they do more averaging. Or, maybe it is the arm swing that jacks with the watch GPS calculations. Regardless, it is the norm, in my experience, to see instantaneous pace swings > 1 minute.

The F5 has an internal accelerometer that it uses for cadence. Check the settings... maybe there is an option to have it use its cadence accelerometer for instantaneous pace.

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 18:37

Post #12 of 17 (4124 views)

Dgconner154 wrote:

exxxviii wrote:

Instant pace on most GPS watches suck. However, there is a super easy fix. Get a foot pod. Then, in the watch's settings for the foot pod, there is an option to tell the watch to use the pod for instantaneous pace all the time. Boom, fixed.

I was hoping to avoid that since I rotate through multiple shoes but it might be my best option. I remember these GPS issues from previous Fenix versions but I thought Garmin had fixed them.

I use a footpod with my 935 and am very happy. Bit belt and braces, and when I use an old pair of shoes for the odd short recovery run then the pace isn't that bad, but that's more steady state. And so whilst you'll wince at this, in the grand scheme of things then footpods are pretty cheap* and so for convenience then getting a couple may be the way for you.

(BTW - You can't used the cadence from footpod or HRM run for pace - stride length varies too much for that and the wrist / chest can't proxy that as the accelerometers are too remote from your feet.)

*in the context only of ST where people talk about $300 adult onesies, pedal cycles that cost more than a family station wagon and a set of handlebars that cost more than a motorbike.

Re: Fenix 5 Pace Accuracy [exxxviii] [ In reply to ]

May 7, 19 18:59

Post #13 of 17 (4111 views)

exxxviii wrote:

Regardless, it is the norm, in my experience, to see instantaneous pace swings > 1 minute.

Maybe across all brands but that hasn't been my experience with Garmin watches. I had a Forerunner 10 and first generation Vivoactive and both were pretty much flawless. In between those I bought a Fenix 3 and it was pretty awful so I returned it almost immediately, but I was under the impression Garmin resolved the problem after the first batch of F3's shipped. At that time I never heard about it being potentially related to the metal case. Regardless, it certainly seems to be true of the Fenix 5.

Before all those I had a Nike+ sportband Tomtom thing that was pretty bad, but it was also probably 8 years ago and consistent with GPS technology at the time.

Re: Fenix 5 Pace Accuracy [Duncan74] [ In reply to ]

May 7, 19 19:02

Post #14 of 17 (4106 views)

Duncan74 wrote:

*in the context only of ST where people talk about $300 adult onesies, pedal cycles that cost more than a family station wagon and a set of handlebars that cost more than a motorbike.

Haha yeah I guess I figured a $500 GPS watch would have a reasonably functional GPS, but I should've known that in triathlon there's always one more thing to buy.

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 19:02

Post #15 of 17 (4106 views)

I never had good instantaneous pace from my Garmin 305XT, 910XT, and 735XT. I have a 945 now, but only have a couple runs and with the foot pod.

Re: Fenix 5 Pace Accuracy [exxxviii] [ In reply to ]

May 7, 19 19:05

Post #16 of 17 (4104 views)

Sounds like I'm getting a footpod!

Re: Fenix 5 Pace Accuracy [Dgconner154] [ In reply to ]

May 7, 19 19:57

Post #17 of 17 (4078 views)

Note this then leads to calibration of footpod debates....

However, I'm pretty happy that the average of the instantaneous pace on the 935 is pretty consistently within 5s /km of the auto lap split at the 1km.

And on any run then I quickly spot the side of the error and adjust as required.

Works for me.

Our Partners

transition-DOT-area-AT-slowtwitch-DOT-com

Advertise with us

©1999-2024 Slowtwitch, Inc., and Slowtwitch.com
Reproduction of material from any Slowtwitch.com page
without written permission is strictly prohibited.