Coros Pace 3 - GPS, HR and Elevation Accuracy Pace 3 is an accurate GPS sports watch but an unacceptably inaccurate HR tracker. Elevation is fine with the caveat that starting elevations aren't always as good as other devices. Coros Pace 3 - 10-mile GPS Accuracy Test - ALMOST the best Updated: 5 Dec 2023 with further test results I must say, I was somewhat surprised by this one. I anticipated the Coros Pace 3 (review) to perform similarly to other recent Coros watches in my GPS test, especially since my previous testing didn't reveal anything exceptionally impressive from Coros's latest iteration of its 'budget' sports watch. So, discovering that it not only passed my testing but even surpassed the best-ever Garmin result was unexpected. It's important to note that this is just one test on one day. Here is the ranking of the top 13 watches, ever, on this test. Suunto Vertical (2023) 92% Coros Pace 3 92% Apple Watch Ultra 2 88% Suunto Race 87% Garmin Epix 2 87% Suunto AMBIT3 RUN 87% Apple Watch SE 87% Coros Apex 2 Pro 85% Garmin Forerunner 955 85% Apple Watch 6 85% Coros Vertix 2 85% Garmin Forerunner 745 85% Coros Apex 46mm 85% To clarify, I do LOTS of other testing based on real-world usage. This particular test is hard and is repeatable. It follows a published methodology which can be replicated by anyone. Satellite conditions change by the minute but so many of them can be tracked by watches these days that the old measures of HDOP aren't really relevant anymore for the kinds of devices we use. Comments Firstly, the Pace 3 uses a bit of a trick similar to what the Apple Watch did a few years ago—it smooths the track. My course is designed to catch out watches that do this, but the Pace 3 hides its smoothing very effectively, to the point where we wouldn't notice unless specifically looking for this behaviour. Perhaps as a consequence, the total distance reported compared to the median was 99.63%. It sounds accurate, and it is, but I would have preferred it to be a bit higher. I specifically noticed instances during the run where the watch seemed to be slightly overstating my pace, and in hindsight, I think it might be due to periodic underestimation of distance. Now, take a look at this quick table where the Pace 3 is the second line of data. Strangely, it performs well in GPS positioning on parts of my test that I consider to be of medium or hard difficulty. This is very unusual. As you can see, it's exceptionally good in that respect. Here are some pictures from parts of the test, comparing the Pace 3 to a couple of other excellent watches on different days. In the straightforward sections, the Pace 3 might be around 5 meters away from the true line. [gallery size="medium" ids="86372,86360,86361,86362,86363,86364,86365,86366,86367,86368,86369,86370,86371"] Most of the recent dual-frequency GNSS watches have shown that the added precision helps in typical reception scenarios but not as much in the situations where it's expected to be most beneficial, such as around tall buildings (urban canyons and real canyons). According to this test, the Pace 3 performs well when near buildings, whether tall or not. In my interpretation, it seems to be the most effective so far in eliminating reflected signals, which is exactly what dual-frequency is designed to achieve. Q: Why is Pace 3 Messing up the easy bits A: I don't know! Well, it's not really causing issues compared to a good watch from five years ago, but oddly, the track can be running parallel to where it should be. This could sometimes be connected to incorrect timings in the received data. However, the parallel alignment wasn't consistently happening from a consistent compass heading. So, when I combine this observation with the smoothed track corners, I'll suggest that perhaps the accelerometer is partially responsible for smoothing the track and that the issue might be there ie that corners can be overshot sometimes. It's just a partial guess. thoughts welcomed. More GPS Tests generally very good to excellent. Multiple rides and runs show great results that there is no point in posting. Easy GPS Ride - Overall, GPS was slightly better than even a handlebar-mounted Edge 540. It was just in the exact right place for most of the time. However, in notable sections, the track was parallel to where it should be but not by much at all. this behaviour was found in other rides/runs but is not concerning to me GPS: Tall Buildings in Kingston This is a surprisingly good performance and just beats FR965 in full multi-band mode. Normally I would expect one good device to beat another one at a certain point but then the other device to win at a later point. This hasn't happened here. Coros has beaten Garmin more times than it lost to Garmin. But all is not perfect as evidenced by the end of the run being off the bridge and in the River Thames where there are perfect reception conditions...very strange. [gallery size="medium" columns="5" ids="86430,86422,86423,86424,86425,86426,86427,86428,86429,86421"] GPS: Surban SW London Pace 3 was the clear winner here over Apple Watch and Garmin FR965 (max GPS mode). The latter 2 were below par today for some reason. Corners were missed and the straight easy paths were not quite right either. I've seen better racks than what the Pace 3 produced today as there were some minor errors here but this was still a great performance from Pace 3. As you can see from the first image, I'm nit-picking. All these devices are fine for strava but if you want errors less than 5m then these are NOT all eliminated on the occasions where there is no apparent reason to give anything other than a perfect track. [gallery size="medium" ids="86437,86433,86434,86435,86436"] GPS Riding There is nothing to see in this test with all devices performing extremely well. Pace 3 was probably the best of the bunch as the others were sometimes on the wrong side of narrow roads but we are talking 3m which I don't consider significant. All tracks superficially look perfect. Trees With the introduction of trees, I expected a good performance from Pace 3 and I got it. However, I messed up this test and left my third device at home. Thus for some of these images, I've added in a track from another device a couple of weeks ago where the track that was used was the same just to give a sense of where the track is as even Google Maps can't see this narrow track through the trees and just guestimates its position. Appel watch and Pace 3 do, at times differ, but I think Pace 3 is the best on the day. Comparisons to the third track don't add much to the equation. The Pace 3 is likely producing a very good track here. It's certainly not perfect but it appears to be better than most devices I've used here. [gallery size="medium" ids="86513,86514,86512,86511,86510,86509"] Heart Rate Tests Overall the heart rate is not good enough but probably fixable. Not good enough on this steady-state run and not good enough on this easier run but it's not too far from being good enough with a bit of tinkering by Coros. not good enough on these intervals especially when the Apple watch on the other wrist did a perfectly fine job same story on these intervals of 1-4 minutes in length Just one little mini-dropout on this smooth hour ride. Excellent! But then with this longer ride. err. Less than excellent. All the other devices including the optical Apple Watch managed perfectly well. Two Elevation Charts Autocalibration (silent) at the start of a workout isn't part of the Coros feature set. But it tracks the correct elevation change once you've started. This second ride in Surrey is clearly better Coros Pace 3 Accuracy Summary GPS accuracy is very good to market-leadingly excellent. Optical HR can be best described with a sentence including the word PANTS. Though that's a bit unfair as I believe Coros will sort it out eventually. Elevation typifies the Coros experience - they have the feature but don't deliver on the details such as the ability to automatically set itself based on the known elevation of starting points like your home.
