The Fenix 9 Pro scored 79% overall in my standard 10-mile GNSS accuracy test, against 92% for the Forerunner 970 on 5 Nov 2025 (here’s the overall test methodology). The score split into 90% on easy sections, 81% on medium sections and 63% on difficult sections. I had high expectations going in, since the tests I’ve already run on this watch have been good.
Garmin may have a new GNSS chipset, though that seems unlikely. What has apparently changed is how it handles GNSS constellations: it no longer appears to use Russia’s less accurate GLONASS system. I assumed a change like that would have been rigorously tested and would improve things, not worsen them.
There were several moments of imprecision in the test:
- the route showed on the wrong side of the road during an easy section
- it bounced off a nearby tall building, a multipath error
- it struggled approaching a tall building near a 50m tunnel
- a tricky section produced a parallel track rather than the real route
Re-positioning after a signal loss took about 10m. My best guess is that the accelerometer-adjusted position in the tunnel drifted off, and the algorithm smoothed the correction back to the last known position, though the exact cause is unconfirmed.
Fenix 9 Pro has a new antenna construction and a titanium case. Either could affect reception quality. Dropping GLONASS could also be the cause, though a tweaked algorithm looks more likely.
It wasn’t the conditions on the day. The other device on the test, the Suunto Run 2, scored 85% after previously scoring 90%, both times worn on the right wrist, the worst side for this test.
Here’s what I mean
Last Updated on 8 October 2026 by tfk the5krunner
Small things I always use
- Garmin 90-degree charging adapter: Charges your Garmin from any USB-C cable. Essential when travelling. I use one.
- Body Glide: The blue anti-chafe stick swimmers and runners carry. I use it.
- Speedo earplugs: Fewer ear infections and no cold-water dizziness. I use them.
- Dryrobe Advance: My winter changing robe for open-water swims. I use one. A cheaper option is the AONYIYI changing robe.
- Maurten: Race fuel that stays easy on the stomach. I use them.
- Beet It Sport nitrate shots: Beetroot shots I take in the days before a race. I use them.
- Garmin charging puck: The quickest way to top up before a session. I use one.
- Injinji: Toe socks that stop rubbing, so you run more. I use them.
- Ultimate toe protectors: Stop black toenails on long runs. They work. I use them.
- Compressport R2 v2 calf sleeves: My calf sleeves of choice. I use them.
- Cellucor C4: My pre-workout before hard sessions.
- TPU tubes: Schwalbe Aerothan, Tubolito and Pirelli SmarTube. Light, tiny spares. I use all three.
- G8 insoles: Adjustable insoles that are good. I use them.
- Cycplus Cube: A 97g electric pump that gets a road tyre rideable in two minutes. I carry one. 5% off with code THE5KRUNNER.
Watches and sensors
- Polar H10: My daily driver for waking HRV.
- Polar Verity Sense: My backup arm-worn HR sensor.
- Nomad bedside charger: Charges my iPhone and Apple Watch overnight. I use it, and many of their bands.
- Train.Red: The best muscle oxygen sensor I’ve used.
- Tymewear: Accurate heart rate and reliable ventilatory zones. I use it to pace endurance rides over an hour.
- Garmin Forerunner 970: A pro-grade triathlon watch. I use this.
- Apple Watch Ultra 4: My daily smartwatch. No phone needed on rides.
- Garmin Fenix 9 Pro: I’ve just bought one.
On the bike
- Continental GP5000 for everyday riding, and Aero 111 on the front for special occasions.
- Helmets: Specialized S-Works Evade 3 for road riding, and Rudy Project Wing for TT-style races. I use both.
- Ravemen FR300: A front light that mounts under your Garmin or Wahoo. I use one.
- Wahoo TRACKR Radar: I use it on one bike and Varia on the other. They perform the same.
- Garmin Varia RTL515: Radar that warns you of cars from behind. I use this model.
- Wahoo ELEMNT Roam 3: The bike computer that’s easy to use. I use mine on most rides.
- Favero Assioma Pro RS2: Accurate power pedals that swap easily between bikes. I use this model.
Home and indoor training
- NPE Runn: Makes my basic treadmill smart, sending more accurate speed and distance to my watch and Zwift. I use it.
- Google Wifi: Keeps Zwift connected in my pain cave. I use it.
- Apple TV 4K: Zwift on the big screen. I use two.
- Google Nest Doorbell (wired, 2nd gen): My video doorbell, running in both Google Home and Apple Home. I use it.
Health, recovery and sleep
- FreeStyle Libre 3 Plus: Shows how my blood sugar responds to diet.
- hDrop: Measures my sweat loss in summer and indoors.
- Fourth Frontier Zone: Checks my heart under load in hard sessions.
- Oura Ring 5: My partner’s recovery tracker of choice.
- Eight Sleep: A cooling mattress cover my partner and I use nightly.
Reader-Powered Content
This content is not sponsored. It’s mostly me behind the labour of love, which is this site, and I appreciate everyone who supports it.
Support the site: Follow (free, fewer ads) · Subscribe (paid, ad-free) · Buy Me A Coffee
Written by real people, with AI assistance. Fact-checked and verified for originality. See the Editorial Policy. FTC: Affiliate Disclosure — some links pay commission. As an Amazon Associate, I earn from qualifying purchases.
tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors. See the gear tfk uses. ID
Is this in SatIQ mode or all band max accuracy?
per second max. as per the methodology doc
So the Cheetah 2 ultra is better: 85% (Easy (90%), Medium (81%), and Hard (81%)).
when scores are close like 83 vs 85 then i would say it is NOT any kind of proof of which is best.
but scores of 79 vs 90 is a sign that one is almost certainly better.
n=1 of course.
and the f9 does seem better in my other tests that i will release in the review.
I am finding mine to be pretty darn good. No worse than the Fenix 8 in my testing.