Race 2 accuracy
-
@Egika I’ve worked in software development for a long time, and with the correct track data, the solution is possible, since it’s not a precision problem but a distance calculation issue (software), as demonstrated on the Sports Tracker website. In the same activity, you can see the distance calculated by Race 2 and by the app on the graph. It’s a 100% software problem and therefore solvable. If the problem is due to processing, could it be that the routes with less error are straighter, while those with more error have more turns? I’ll try a completely straight route in the next few days to see what happens…
-
@isaac.net sorry, you are on the wrong track.
While probably everything might theoretically be solvable by software, I doubt that Suunto is going to invest a lot into this one. But who knows…t6, S6, Elementum Terra, Ambit 3 Sapphire, Spartan Ultra Copper, Traverse Alpha, S7 Graphite LE, S9B Ambassador, S9P Titanium, S9PP Titanium, Vertical All Black, Race Titanium Charcoal, Race S Titanium Courtney, Run Lime, Race 2, Vertical 2 Titanium
-
@Brad_Olwin said in Race 2 accuracy:
@jjpaz what I posted are raw data from JSON files in quantified self. One of the watch recordings is no longer in the Sunnto database. I believe 3% is the acceptable GPS error for handheld devices.
When I upload Suunto JSON files in QuantifiedSelf the distance showed is the same as summary distance saved the FIT file, not corresponding to the gps raw data distance.
If you want (and have time) you can compare a short activity wearing Race 2 and another watch and repeat the test.Maybe our expectations regarding accuracy in Race 2 where higher, moreover comparing with other watches. In my case I combine Vertical and Race 2 in my trainings and I know that I have to apply a “mental calibration” when I compare data with both watches, and that’s all. In general I’m happy with Race 2, despite its behavior is very reliable when I repeat circuits.
Thanks for your contribution.
-
I’ve got about 1 week left of my return window…I’ve already sent one back as I wondered whether it only affected certain units and hoped I might be lucky second time round. I was also banking on it being addressed in the update…to me the accuracy fix would’ve been better than all the new features that came along. Might be time to try a Vertical 2…
-
Hello,
On the 24th, I conducted some tests, first on a practically straight route, and then on a route in the same area with hills and curves. My hypothesis that the Race 2 is incorrectly processing the recorded points was confirmed. The straight route is marked every 500 meters; it was 4.04 km according to the Race 2 and 4.05 km according to the track, measuring almost exactly during the activity. During the activity with curves, the problem returned, subtracting 80 meters from the total: 4.00 km according to the Race 2 and 4.08 km according to the track.I’ve attached some screenshots that I will send to Suunto support:
I encourage you to conduct these tests and also send them to Suunto (support@suunto.com). It’s the only way they’ll take the issue seriously. If this problem is widely known, I doubt Suunto will sell another Race 2 at its current price.
Regards.
-
-
There’s an user in reddit u/slimak131 that wrote a program to evaluate the quality of a looped track. It seems pretty intesting for testings. I’m posting here the info
Source: https://www.reddit.com/r/amazfit/comments/1thef8o/amazfit_cheetah_2_pro_vs_garmin_forerunner_970/
Links:
-
Super interesting thread!
I guess that is the curse of a consumer device. On one side we have a lot people shouting loudly that they ran marathon and their watch counted 42,66 kms and on the other side we have geeks and purists like us trying to get as raw number as we can get. And Suunto have to find a balance between all. Haven’t used my Race 2 for marathon or HM so cannot tell, but I assume it shows closer number to actual distance. I wonder if that is the reason for this behavior. -
@aiv4r in my opinion, It doesn’t seem to be the problem with Race 2; point capture is very good. You only need to look at the track generated by the captured points. In terms of repeatability, I think Race 2 does very well. The problem arises later, during post-processing of the collected points. That’s when Race 2 shortens the distance, and by shortening the distance, I mean that on a course with turns of a known distance, Race 2 makes some kind of cut, showing a distance shorter than the real distance and also shorter than the track saved by the device itself.
-
said in Race 2 accuracy:
Hello,
On the 24th, I conducted some tests, first on a practically straight route, and then on a route in the same area with hills and curves. My hypothesis that the Race 2 is incorrectly processing the recorded points was confirmed. The straight route is marked every 500 meters; it was 4.04 km according to the Race 2 and 4.05 km according to the track, measuring almost exactly during the activity. During the activity with curves, the problem returned, subtracting 80 meters from the total: 4.00 km according to the Race 2 and 4.08 km according to the track.I’ve attached some screenshots that I will send to Suunto support:
I encourage you to conduct these tests and also send them to Suunto (support@suunto.com). It’s the only way they’ll take the issue seriously. If this problem is widely known, I doubt Suunto will sell another Race 2 at its current price.
Regards.
I used the program with the track with curves that I uploaded in a previous post (removing the final section that was off the track). It confirms my suspicion that Race 2 doesn’t have accuracy problems in data capture; it’s an error in processing (software).
Only 1.51m of drift on the 2-lap circuit with curves, asphalt, and clear skies:
Gemini Smart Track Drift v23 ---------> START
Autonomous Mode (Method 1). Treatment: 2026-04-24_curvo.gpx…**REPORT FOR: 2026-04-24_curvo.gpx (METHOD 1)
Parameters: 3 min / 40 m
Total distance: 3698.0 m
Comparison distance: 3698.0 m
Number of samples: 1067AVERAGE DRIFT: 1.51 m**
-
Hello,
I can confirm my R2 shows always a litte shorter distance than my Ambit 3 (about 1%). This is not a tragedy but a software fix would be appreciatedRace 2
Previously : 9 baro, Spartan sport, Ambit 3 -
@isaac.net I get that
was just wondering if Suunto added artificial cut of distance for masses, that usually run more than actual race distance. (mostly road, since trail folks usually do not care that much about ±400meters). -
said in Race 2 accuracy:
@isaac.net sorry, you are on the wrong track.
While probably everything might theoretically be solvable by software, I doubt that Suunto is going to invest a lot into this one. But who knows…I have to stand corrected. Seems Suunto is indeed investing into this one
-
@CHRGBR said in Race 2 accuracy:
Hello,
I can confirm my R2 shows always a litte shorter distance than my Ambit 3 (about 1%). This is not a tragedy but a software fix would be appreciatedComparing against Ambit 3 isn’t as straightforward as it may seem. For example, when running on deeply forested trails in my area Ambit 3 was always 3-5% shorter (less accurate) than modern Suunto watches.
-
Thanks for your feedback — it helps us improve with every update.
We hear you, and we act on it.Your feedback is extremely valuable, and our team continues working on GPS accuracy improvements and optimization through future firmware updates
Technical & Product Specialist – Suunto Iberia
-
@Joaquin Thanks!!
-
@Joaquin this is excellent news. Thank you so much!!
-
@jjpaz @dreamer_ Interesting test
This test was performed on a very short and technical mountain loop under dense tree canopy.
Loop characteristics:
• Wheel measured distance: 497 m
• Total laps: 11
• Expected real distance: 5.467 km
• Clockwise direction
• Dense forest coverage
• Repeated technical turns including one ~180° hairpin and two additional closed turns
The loop contains:
• Curve 1 → ~180° hairpin
• Curve 2 → ~90° closed turn
• Curve 3 → ~85° closed turnThese repeated direction changes make this route extremely demanding for GNSS filtering and track reconstruction.
One important detail:
all watches were worn in different wrist positions, so small variations are completely normal. Watches placed slightly higher on the arm usually record slightly more distance due to arm swing and antenna orientation.
Results:• COROS Apex 4 → 5.37 km (-1.8%)
• Suunto Race 2 → 5.36 km (-2.0%)
• Suunto Vertical 2 → 5.33 km (-2.5%)
• Garmin 970 → 5.30 km (-3.1%)
• Amazfit T-Rex Pro 3 → 5.14 km (-6.0%)A very interesting detail appeared when comparing GNSS raw distance vs filtered activity distance.
This is where you can clearly see the work of each brand’s algorithms trying to reconstruct the “real” trajectory under dense canopy conditions.
GNSS Distance represents the raw satellite accumulation, while Distance is the final filtered value after each brand applies its own correction, smoothing and trajectory reconstruction algorithms.
The most impressive result here was the Suunto Vertical 2:
• 5.33 km GNSS Distance
• 5.33 km final DistanceAn almost perfect match between raw GNSS data and filtered output, showing extremely confident trajectory processing in this test.
COROS and Suunto Race 2 also stayed very close between raw and filtered values, while Garmin showed a more aggressive correction approach:
• 5.44 km raw GNSS
• corrected down to 5.30 km final distance
With the exception of the Amazfit, the distance difference between the other four devices is completely normal considering the different wrist positions and the extremely difficult GNSS conditions during the test.
ENJOY!!!
Technical & Product Specialist – Suunto Iberia
-
@Joaquin Thank you very much for your testing efforts. Is the software version used the same one available to users?
On the other hand, it’s good that the watch performs well when making corrections under extreme conditions, but it would be important to focus on what’s being discussed in this thread, where the correction causes errors under ideal conditions, which I believe is the most common scenario for a Race 2 user, and where the result should be perfect after the corrections.
-
@isaac.net not, working on it
of course, we must do more and more Tets but looks promising
Hello! It looks like you're interested in this conversation, but you don't have an account yet.
Getting fed up of having to scroll through the same posts each visit? When you register for an account, you'll always come back to exactly where you were before, and choose to be notified of new replies (either via email, or push notification). You'll also be able to save bookmarks and upvote posts to show your appreciation to other community members.
With your input, this post could be even better 💗
Register Login