As with the Kiprun GPS 500, Decathlon commissioned Coros to develop a second, more upscale multisport watch, the GPS 900, which is also adorned with the suffix “by Coros” that leaves no doubt as to the question.
Using the same method as its previous creation commissioned by Decathlon, the American manufacturer has based the development of the GPS 900 on a previous generation model. As the GPS 500 took on the characteristics of the Coros Pace, the GPS 900 in turn uses the hardware of the Coros Apex. Devices that have been tested without being outdated and that therefore allow Decathlon to offer its Coros GPS 900 at a very attractive price of €249.
Compared to the Kiprun GPS 500, the Decathlon GPS 900 by Coros mainly gains an altimeter, better autonomy, a more sophisticated finish, navigation (without base maps) and sports and data modes dedicated specifically to outdoor practices such as the trail.
ergonomics and design
Based on the Coros Apex 46mm, the Coros GPS 900 features several processing details. Its stainless steel bezel is therefore riddled with notches and protects the contours of a glass no longer made of sapphire but simply made of Gorilla Glass (and therefore scratch-resistant) to reduce its cost. The case of the watch remains in polycarbonate, with a metal plate covering the underside. The assembly is clean with no visible screws, but this suggests the use of glue (possible more delicate repair).
The Decathlon GPS 900 watch from Coros
The watch also boasts a 5 ATM certification, meaning it can be submerged and swim underwater, but not water sports that could subject it to heavy use (surfing, etc.).
Coros’ Decathlon GPS 900 remains lightweight; We weighed it with its silicone strap at 59g (39.5g without). Without being particularly compact with its 46mm format (47mm measured from one edge of the case), it doesn’t appear bulky and is discreet on the wrist, aided by a thickness of 12.2mm (13.1mm considering the sensor island).
Its silicone strap is classic. Very soft and elastic, comfortable to wear. Its standard format of 22mm allows for easy replacement.
In terms of display, we’re sticking with a 1.2-inch transflective MIP LCD screen that only displays 64 colors but offers excellent readability in direct sunlight. An automatic backlight is available so that it lights up when we point it at ourselves with a simple twist of the wrist or as soon as we press a button.
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interface
As a good sports watch, the Coros Decathlon GPS 900 gives pride of place to displaying activity data. In addition to the date, time and battery level, the standard dial also shows the duration of the sporting activity, the calories burned and the number of steps taken, as well as the altitude and heart rate. 4 other watch faces are available and you can download more in the Coros application.
The Coros Decathlon GPS 900 user interface: standard watch face, then widgets (backlight disabled in the 1st photo on the left)
Since the screen isn’t touch-sensitive, navigation is done solely with the button-wheel-button duo on the right side of the watch. A rotation of the dial scrolls through the various widgets: last night’s sleep summary, mileage, fatigue level, recovery, calories burned and activities, heart rate, altitude, barometer, skin temperature, sunrise and sunset times, sun and finally notifications.
Decathlon GPS 900 by Coros Widgets
For most of these widgets, pressing the crown button gives you access to more detailed information. However, the full data can be viewed in the Coros application.
The main menu, in turn, opens with a simple press of the button on the wheel. You can then access settings, sport modes and training.
A notification will appear on the GPS 900, then the main menu with the start of a race activity
The additional functions, in turn, are displayed in the form of icons distributed in a ring around the edges of the screen (5th image on the module above). They are simply scrolled with the wheel to quickly activate the “do not disturb” mode, start a stopwatch, set an alarm clock… However, the associated functions are reduced to a trickle, you have to deal with the display of notifications content and action cam controls. Unfortunately, the GPS 900 does not support music playback.
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Application
For the Coros GPS 900, Decathlon has not bothered to develop a specific application. The watch works with the Coros app (iOS and Android) like all other watches from the manufacturer of the same name. We won’t complain as it is complete and well organized.
When opened, the home screen shows the latest data measured by the watch to give an overview of our day. Sleep tracking, last sporting activity, average heart rate, calories burned and number of steps since the start of the day are displayed in the form of overlaid tiles. Just touch them to access the corresponding data history.
The Coros app with the Decathlon GPS 900 by Coros watch
The second tab of the application lists the dates of the activities performed in chronological order. Detailed reports allow us to analyze our sports sessions and extract or share information.
In order to keep an eye on our performance, the app summarizes various measured values and evaluations in a third tab, such as VO2 Max, resting and threshold heart rate, marathon level, threshold rhythm… Calculated data thanks to our in-house “EvoLab” algorithm based on our latest activities. In the same vein, a Race Predictor gives an estimate of the duration and average pace that can be targeted at the flagship distances of 5km, 10km, half marathon and marathon.
This third tab of the application also houses the training management tool. We can download or create more or less complex ones depending on our goals. It is also possible to import routes (GPX files) to transfer them to the watch and then follow them with its navigation function.
Use and Accuracy
As it’s based on a previous generation Coros watch (the Apex), the Coros Decathlon GPS 900 obviously doesn’t have the latest refinements in terms of sensors. It’s not ridiculous because of that, but you have to know your limits.
Tested in endurance and interval runs as well as indoor rowing, the GPS 900 shows its performance. In our interval runs, the heart rate peaks are clearly visible. However, sometimes the clock shows a delay and a delay of a handful of beats per minute, even when a more regular rhythm is found.
The heart rate curve of the Coros Decathlon GPS 900 (in purple) compared to that of the Polar H10 chest strap (red), which serves as our reference, during an interval run.
The reliability of the heart rate measurement also depends heavily on the activity performed. Coros’ GPS 900 therefore completely derails during our rowing sessions and fails to detect the sudden increases in heart rate. Even tightening the watch or wearing it on the other wrist does not change that.
The heart rate curve of the Coros Decathlon GPS 900 (in purple) compared to that of the Polar H10 chest strap (red), which serves as our reference, during an interval row session.
In terms of geolocation, good surprise, the Coros Decathlon GPS 900 is pretty accurate. However, it’s not as good as a watch with dual-band GNSS mode like the Garmin Epix Gen 2, especially in traffic-heavy environments (forest, city center, etc.). The altimeter also appears to be sufficiently accurate, which is particularly useful for hiking and trail enthusiasts.
The GPS track of the GPS 900 (in blue) compared to that of the Garmin Epix Gen 2 (in orange, dual frequency enabled).
autonomy
Coros’ Decathlon GPS 900, which was promised to be very durable, actually worked for 3 weeks on a single charge on our wrist. This corresponds well to the 20 days of intensive daily use (automatic backlight, sleep monitoring and very frequent notifications) that Decathlon indicates in its technical sheet. This is still fine with the default heart rate tracking setting, which only takes a reading every 10 minutes. Switching to the “real time” setting reduces the autonomy by several days. In this case, you should still count on at least 2 weeks of autonomy.
As with all watches, GPS use in particular consumes the most energy. We’ve seen a drop of about 3% per hour, for a total of about thirty hours of use. For long-distance adventures, an Ultramax mode is also available, reducing the recording time to 30 seconds every 120 seconds.
When it’s time to charge, simply plug the cable into the proprietary connector on the back of the watch, which you plug into a smartphone power adapter or a computer’s USB-A port. Take about 2 hours to replenish your energy.
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strong points
Complete app.
Good GPS tracking.
Good autonomy.
Simple interface.
weak points
Cardio follow up in halftone.
No music playback.
Small screen for a 46mm format.
Other sport modes would not be rejected.
Diploma
Global brand
How does the classification work?
Despite its reasonable price for an outdoor multisport watch, the Coros Decathlon GPS 900 is well made and offers the essential features that outdoor enthusiasts have a right to expect. You’ll appreciate the good GPS precision and the autonomy, but you’ll be keen to equip yourself with a chest strap or a cardio bracelet to compensate for the unreliability of the watch’s cardio optical sensor.