Pace accuracy

Former Member over 8 years ago

I just spent some time reading through (some) of the 55 page "GPS Accuracy" thread. Some of what I'm experiencing is touched on there, but I'm much more concerned about the pace problems I'm having with my F5 than laser-perfect distance accuracy. Specifically, I've noticed that my pace is all over the place during a run, even when I know I'm holding a very steady one. For example, here is the pace data from today's run:

I can understand some minor deviations, but when I'm running for several miles at what I know to be a sub-7 pace and look down at my watch and see "8:40", that's pretty darn frustrating.

Here's what the exact same run looked like two weeks ago with my old FR220:

Totally difference experience. What gives? Do I need to change the GPS settings on the F5 to something other than what comes default?

0 andi00000001 over 8 years ago

Today I noticed the Fenix saying I'm doing 6:55 mile pace. Had to laugh. My other watch said 8:00 which is about what I was actually doing.

Here's where I ran (via non-Garmin):

Got home and checked the track in that area on the Garmin, and all is explained, it had me running way off course and back again:

A few mins later it said I was doing 9:20...

0 ChevronLugs over 8 years ago

On theory is that the the ceramic antenna you are pointing out actually uses the bezel as the Exo Antenna so how it points does not matter.

Let the wrist tests begin (could almost copy this from the fenix 3 launch and subsequent tests :) )

Yep, that's the theory, but the patent application which has diagrams didn't seem to apply to the f5. EXO antenna, given the usage of EXO, would also seem to imply some sort of exoskeleton or external antenna design. However, in the f5X tear down it doesn't appear there's any connection from the semi-circular patch antenna to the bezel. There could be a connection through the display ribbon cable, but that's a big 'ole wild guess.

I'm betting on "EXO antenna" being nothing more than marketing speak.

0 ChevronLugs over 8 years ago

We don't need to guess at the location of the antenna in 5/5S. The internal photos from the FCC links that I provided in my previous post have an arrow labeled "antenna" pointing right at the antenna. It appears to be located at the bottom of the watch face (6 o'clock position), so that it would be facing up and out when running. The antenna is ceramic white and square.

I've read that a ceramic patch antenna needs to be around 25x25mm for both GPS+GLONASS, and if so, there's no way that dinky thing is the antenna. I'm guessing that's Bluetooth.

The real mystery is where the same antenna is on the 5X, where the FCC internal photos look quite different.

In the 5X tear down, you can clearly see what looks to be an antenna at the 12 o'clock position. Is it truly an antenna? Looks big enough to be one, and it mates up with 3 spring type connectors on the main board. Those three connectors are present in all the FCC docs for the 5 series, yet the Chronos is the only one pictured with the supposed antenna.

I wonder if a missing part of the analysis, particularly as between the GPS accuracy between 5 series and the 935 relates to the weight of the watches. I notice that as I run and my arms get sweaty, even after cinching down the watch fairly tight, the 5X starts sliding around a bit. The weight of the watch means that with each impact, the watch face gets pulled down my wrist, moving the antenna (assuming it's at the 6 o'clock position of the watch face) so it's more facing the ground than the sky. I previously wore a 620 which was pretty light and didn't have this twisting problem, and the 935 is also pretty light compared to the 5 and 5X. Given that the 935 has had generally better GPS performance, people have largely attributed that to the bezel and materials. What if another contributing factor is just that the weight of the watch twists the antenna toward the ground with each impact?

I was thinking about that one as well, and whether weight is contributing to the watch moving too much, and separately from the wrist. Wouldn't Garmin factor that movement in with their super duper algorithm that calculates speed/distance/cadence/etc...?

0 Former Member over 8 years ago

I see ChevronLugs has moved beyond being pedantic about marketing speak :D

To answer some of the questions in here with regards to the 5X teardown pictures, the 5X, like the rest of the F5 family has a trace PCB antenna at the 6 position for wifi/BT/ANT+. The design of the trace antenna differs between the 5X and the 5/5S. The FCC docs refer to to the wifi/BT/ANT+ antenna as that's the only thing transmitting and therefore requires FCC approval.

The 5X has a GPS antenna (potentially usable for wifi/BT/ANT+ as well but highly unlikely) comprised of two parts. The first part is embedded in the bezel itself, the Exo antenna, and the second part is within the case body at the 12 position. The two are likely joined into a single overall antenna using an inductive coupling. More information here:

https://forums.garmin.com/showthread.php?374196-Antenna-Design-Fenix-5-5S-vs-5X-vs-Chronos-vs-Fenix-3

0 ChevronLugs over 8 years ago

I see ChevronLugs has moved beyond being pedantic about marketing speak :D

Eh, it wasn't about the marketing speak. Although, the marketing speak was so very bizarre. For me, it was the quote CHIMPWARE pulled from the Garmin US site, and subsequently disappeared. You know the rest. It's all good. :)

0 budish over 8 years ago

I've read that a ceramic patch antenna needs to be around 25x25mm for both GPS+GLONASS, and if so, there's no way that dinky thing is the antenna. I'm guessing that's Bluetooth.

Ah, my bad. I saw antenna and thought "GPS" but you're of course right that there are other (wifi, bluetooth, etc.) antennas and given that these disclosures are about wifi and bluetooth, it makes sense that would be the antenna they would flag.

0 MalcolmLavery over 8 years ago

Mine had me jumping from 6 min to 13min pace on last nights run. I was running with my wife at a constant 8:30 of perfectly flat route along a canal. This thing is useless for keeping pace. So wish I had not paid all that money out now, thinking I would have one of the best watches out there. Wrong! Should have stuck with my FR630, which never let me down.

0 meste7 over 8 years ago

Mine had me jumping from 6 min to 13min pace on last nights run. I was running with my wife at a constant 8:30 of perfectly flat route along a canal. This thing is useless for keeping pace. So wish I had not paid all that money out now, thinking I would have one of the best watches out there. Wrong! Should have stuck with my FR630, which never let me down.

Suggestion: run app DozenRun which can show average pace for 3-30sec (adjustable) and will get a better view of your actual pace.

0 R_Tellis over 8 years ago

I use the CIQ data field Configurable Pace set to 30 seconds along with lap average pace on my main screen. Works like a charm.

0 Markyz85 over 8 years ago

I useConfigurable Pace. Works like a charm.

Configurable Pace is F5 compatible?