Full test Kiprun GPS 900 by Coros from Decathlon: what you need to know - GPS watches test

As we announced to you in February (read our brief presentation of the model), Decathlon, in partnership with the equipment manufacturer Coros, offers the GPS 900 by Coros, a premium outdoor watch at an unbeatable price: less than 250€!

This model joins the Kiprun GPS 500 by Coros (see the differences between GPS 500 and GPS 900 and where to buy), the entry-level model for runners released in late 2021. The GPS 900, which is much better equipped, is aimed more at outdoor enthusiasts looking for a watch that offers high precision altitude and elevation measurements and functions for finding your way around.

Compared to the range of Coros watches, the Kiprun GPS 900 falls between the PACE 2, the entry-level model for runners and triathletes, and the APEX 2 and APEX 2 Pro models for outdoor use. It is also close to Garmin's Forerunner 255. It is based on the old APEX, with the same design and some components (see below) but with improvements. It benefits from the whole Coros environment (application, Evolab, Training Hub, updates, accessories, software updates).

	GPS 900	PACE 2	APEX 2	Forerunner 255
Price	249 €	199 €	479 €	349 à 399 €
Screen	240x240 px	240x240 px	240x240 px	260x260 px
Weigh	58 g	30 g^(*)	42 g^(*)	49 g
Bezel and buttons	Aluminium	Plastic	Titanium	Plastic
Barometric altimeter	•	•	•	•
Touch screen	X	X	•	X
Multiband GPS	X	X	X	•
GPS navigation (track, breadcrumb trail, back to start)	•	X	•	•
Autonomy	35 h / 30 d	30 h / 20 d	45 h / 17 d	30 h / 14 d
Test of the model	In this article	Test	Test	Test

In terms of features and functionality, the GPS 900 is quite similar to the APEX 2 but with a lower specification to offer a more affordable price. It does not offer mapping, MP3 player or pulse oximeter. Its autonomy is a little weaker and its materials a little less high-end. However, Decathlon wanted to offer a robust and reliable model and this is what we wanted to verify through our tests.

Here is a detailed review and our full test of the GPS 900 by Coros. You will find our opinion at the end of the article. For an overview of the model in less than 40 seconds, see our video presentation below.

Who is the GPS 900 by Coros for?

The GPS 900 by Coros is aimed at all sportsmen and women, but it is particularly suitable for outdoor enthusiasts, especially those who need precision in altitude and elevation measurements. Thanks to its instruments and GPS navigation functions (track and trace), it is perfectly suited to mountain sports such as hiking, trail running, skiing/cross-country skiing/snowboarding, but also running, track racing, triathlon, cycling, swimming or weight training.

We tested the Decathlon GPS 900 by Coros for 2 months with a model that Decathlon lent us. The comparative graphs (altimeter, cardio, distance) are produced by a tool developed by Sport Passion. For all the tests or detailed reviews that we carry out, we do not receive any remuneration from the manufacturer. We do not publish sponsored content on our site. All our tests are independent of brands. Our goal is to offer Internet users free, neutral, reliable and useful information to help them in the choice, purchase and use of sports equipment (watches and fitness equipment). See all our tests.

Data sheet

Weight
58 g

Dimensions
46 x 46 x 11.9 mm

Display
Colour transflective (MIP), 1.2" (30.5 mm), 240 x 240 px, 64 colours, always ON, Corning Gorilla glass

Autonomy
35 h / 30 d (GPS only/watch)

GPS
multi-GNSS

True multi-sport
Yes (triathlon profile)

Recommended Activities
Outdoor (trail, ski, hiking, cross-country, snowboard), running, triathlon, walking, cycling, swimming, weight training - Approximately 20 sports

Connectivity
iPhone, Android. Bluetooth wireless data transfer

Cardio frequency meter
Yes, wrist optical

Topographical maps
-

Payment system
-

Music player
-

Telephony / 4G
-

ECG
-

Barometric altimeter
Yes, auto-calibrated or manual

Compass
Yes

Thermometer
Yes

Weather
Atmospheric pressure monitoring, thunderstorm alerts.

Waterproof
5 ATM (50 m), swimming only

Other
Running power without external sensor, full sports functions and physiological measurements, route tracking, return to start, altitude profile, tool-less interchangeable strap

Other models
Coros PACE 2: entry-level triathlon and running
Coros APEX 2: premium outdoor, triathlon watch

Design, technical specifications and price

Design and technical characteristics: an elegant, robust and light model

The GPS 900 by Coros has the same design as the previous model Coros APEX. It has the same format, two identical buttons, including the famous digital knob, which is very practical for navigation, and a 1.2" transflective colour screen.

The case, made of resin (ABS), measures 46 mm in diameter and 11.9 mm thick, equivalent to the size of the previous APEX 46.

The aluminium bezel has been redesigned. Its bevelled shape prolongs the rounded shape of the case, which it hugs perfectly and gives the impression that it is a little smaller than its actual size. Its dark grey colour is perfectly balanced: light enough to keep any scratches that may have accumulated over time unobtrusive and dark enough to offer a discreet, yet visible, contrast with the black colour of the case. This watch offers a sporty yet elegant look.

The glass, made of Corning Gorilla, a highly scratch-resistant material, is smooth and pleasant to the touch. It is well protected by the bezel, the edge of which is very slightly raised (less than 0.5 mm) from its surface. So there is no risk of scratching the glass. Less resistant than sapphire but also less expensive, Corning Gorilla has the advantage of being more translucent and less generating reflections. For reading comfort, we preferred the screen of the GPS 900 to that of the APEX 2 and its sapphire glass.

On the back of the watch, there is an optical heart rate monitor on the wrist (more on this later) and Coros' own charging connector. The case back is made of aluminium and is inscribed with Decatlon preceded by the new group logo (an underlined D).

The GPS 900 weighs only 58g with its silicone strap, 5g more than the APEX 2 or 8g less than the APEX 2 Pro with the same strap. This is a lightweight model that you can hardly feel on your wrist.

Finally, this model is 5 ATM waterproof, which means it can be used for swimming and in the rain or snow. However, it cannot be used for diving (or even jumping off a diving board) or impact water sports such as canyoning or kite surfing.

The bracelet: comfortable but a little big for small wrists

The watch is equipped with a 22 mm black silicone strap that can be changed without tools. It has a classic pin buckle and 2 passer-by. This strap is very soft and a little elastic, which makes it easy to tighten on the wrist. It is comfortable to wear and easy to put on, but tends to attract dust. However, this is not noticeable from a distance.

We found it a little big for a thin wrist (15 cm circumference). The second to last hole was sufficient for everyday use, but for sport, an extra hole would have been useful to ensure a good tightening for reliable heart rate measurements. Decathlon only offers one size of wristband for this model but it can be changed to a compatible Coros brand wristband, for example an ultra-light nylon wristband.

We found the bracelet to be robust and durable. After 2 months of daily use, 24 hours a day, only the passers-by had lost some of their shine. The bracelet was still intact.

Wristband — The silicone strap is comfortable and seems durable. It attracts a little dust (click to enlarge)

Silicone strap — It is a little long for small wrists (circumference less than 15 cm). We used the last hole for sports.

Interchangeable Quickfit bracelet — This bracelet is interchangeable without tools. It can be replaced with a compatible 22mm Coros bracelet.

The screen: up to 6 sports data

The GPS 900 has a 1.2" diameter (30.5mm) transflective display (MIP) in 240 x 240 px, a standard definition for a sports watch, and offering 64 colours. The same screen is found on the APEX 2 but in a smaller case. The screen to case size ratio is smaller on the Decathlon model (44% of the total display area versus 50% for the APEX 2), resulting in a larger black border around the screen (see our comparison photo below).

This permanent display is very readable, especially in sunlight, thanks to its MIP technology which uses the outside light as illumination. At night or when it is a little dark, the backlight can be used. It can be activated from the buttons or with a simple movement of the wrist (the function is configurable). We'll come back to this in the Handling section. The watch also has a night mode which activates a permanent low intensity backlight for night-time use.

In sports mode, the GPS 900 can display up to 6 data fields compared to 8 on the APEX 2. The display is comfortable.

Screen border — The screen to case size ratio is smaller on the GPS 900 than on the APEX 2 (left), resulting in a slightly thicker black border. The APEX 2 Pro, in the centre, offers a larger screen (33mm) in a similar sized case to the GPS 900.

Sensors: everything you need for the outdoors

In terms of sensors, the GPS 900 is well equipped for all sports, especially outdoor: GPS chip, ABC sensors, wrist cardio. You will find our test of these components below. Decathlon told us that the GPS chip and the optical cardio are the same as in the old APEX model, but that the CPU and battery have been replaced.

The Multi-system but not multi-band GPS (like the APEX 2) offers 3 GPS operating modes:

The watch is equipped with a barometric altimeter, an essential sensor for outdoor trips where the availability of measurements on the watch (vertical drops, 3D speed, ascent rate, etc.) and their accuracy is essential. It can be calibrated manually or automatically from the GPS before the start.

Optical wrist heart rate monitor and comparison with APEX — The optical wrist heart rate monitor of the GPS 900 (right) is the same as the one used in the old APEX. On the left, the APEX 2 and APEX 2 Pro watches.

There is also an accelerometer (useful for indoor sports) and a digital compass.

Like all Coros models, the GPS 900 offers wrist power measurement without an external sensor, a handy training tool for runners and racers.

Finally, it is possible to pair it with external Bluetooth sensors (POD, cardio belt) and, soon, a Stryd power sensor.

However, there is no pulse oximeter to measure blood oxygenation and assess altitude acclimatisation, nor is there an electrical ECG sensor, used on some Coros watches to accurately measure heart rate variability (HRV) and deduce stress levels.

Handling: an easy-to-use and practical model

Installation and use of the model

The GPS 900 is set up and used just like any other Coros watch. It's quick and easy to set up from a smartphone. It only takes 2 minutes to install the application Coros (new Coros or Kiprun users only), pair the watch, enter some practical data (gender, weight, etc.) and wait for it to be updated with the latest software version. Then you can use it!

The watch is used with the Coros Smartphone application (the same one used by Coros users), which is easy to use. Some data can also be accessed from a computer via the Coros Training Hub. We describe all this below.

The watch can be set up from the application in a few clicks (customisation of sports profiles, choice of dials, etc.).

The transfer of sports data from the watch is done automatically via Bluetooth (to be activated on the phone if it is not already). So you don't have to do anything special to find all your data in the application after a ride.

An ultra easy-to-use navigation interface

Like all Coros watches, this model benefits from an easy-to-use interface facilitated by the digital knob. If you are not used to Coros or Decathlon watches, don't worry: it is really easy to get used to.

The notched wheel, large enough to be used with gloves, turns in either direction and allows you to scroll through widgets, menus, tools and sports screens or zoom in on the breadcrumbs during a ride. It can be pressed to confirm an action, start or stop a sport. A haptic feedback (small vibration emitted during the rotation for each new display, as with a real cogwheel) allows a better control of the movement.

The bottom button allows you to go back, scroll through the various complications displayed on the screen (steps, calories, etc.) or record a lap during sport. A long press on it opens the toolbox (functions offered by the watch and settings).

The scroll wheel is really useful for scrolling through the screens and menus. The scrolling speed is perfect except, for our taste, for displaying the training summary at the end of a sports outing. Unlike other Coros watches, you have to turn the knob a lot to scroll through the data, as the display is almost line by line!

The buttons can be locked to prevent mishandling, especially during sport (only scrolling is allowed).

A model that can also be used by left-handed people

This model can be used on any wrist. If you are left-handed, you can place the watch upside down to keep the buttons on the left side. Simply adjust the watch settings to reverse the display and possibly change the direction of rotation of the wheel.

The backlight

At night, or when it is very dark, it is necessary to activate the backlight to read the screen. It can be activated by rotating the wrist or using the buttons. However, its brightness cannot be adjusted. It is programmed to be inactive during sleeping hours but can be activated by pressing a button or turning the dial. It is best to lock the buttons to prevent accidental activation, as the wheel can easily turn when it comes into contact with the sheets!

More than 100 dials or watchfaces available

Coros currently offers a hundred dials in the application and 5 by default on the watch. Customisation is limited to the choice of colours. Most of the screens offer a few default complications (altitude, steps, calories, heart rate, activity time, sunrise and sunset times) that can be scrolled through at the touch of a button.

Customisation of the watch

This template offers limited customisation of the training menu (available sports activities) and the toolbox (available features) but not the widgets. Coros only allows you to change the order of activities and functions or to remove them.

Each sports profile can be customised in terms of the screen and the data to be displayed (we list this data below).

Use of the model

The GPS 900 is easy to use. Users who are used to Coros will find their bearings immediately. Others will have no trouble using the watch without having to refer to the user manual.

The widgets are accessed by turning the wheel: sports performance display (running performance, fatigue level, recovery), activity data summary (steps, calories, floors climbed, activity time), 24-hour graphs (heart rate, altitude, air pressure, temperature), sunrise and sunset information, smartphone notification screen.

A long press on the bottom button opens the toolbox. It offers various practical functions and is accessible during sport: compass, metronome, Ultra Max mode, GPS navigation tools, breadcrumbs, location recording, satellite map, stopwatch, timer, alarm, choice of dial or watchface, night mode, camera control, do not disturb mode, battery manager, heart rate broadcast, settings.

A sports activity is launched from the notched wheel: press to display the sports activities, move the wheel to scroll through the sports, press again to launch the activity. A simple press on the wheel (after unlocking the buttons if necessary) pauses the activity. A long press ends it and displays a summary of the outing.

Sports and outdoor functions

Sports profiles: about twenty available on the watch

The watch offers about twenty outdoor-oriented sports profiles. There are slightly fewer than on the APEX 2 and APEX 2 Pro models due to the limited memory on this model.

For example, there is a triathlon profile that allows you to do 1 to 3 activities among those of the triathlon (swimming in open water or in a pool, cycling, running) but no Multisport profile allowing you to do any activity.

The mountaineering and climbing profiles are absent from this model, as are certain water sports such as speedsurfing and windsurfing, which are well represented on the APEX 2. Winter sports are also a little less numerous. Ski touring, which would be well suited to this model, is not included.

Each profile displays sport-specific data by default, such as the count of jumps and breaks in jumping, the number of repetitions or movements in weight training, rowing and rowing, or the separate count of ski runs and climbs.

The Track Run profile allows you to specify the track number you are riding on. After 2-3 laps, the watch recognises the track and aligns the GPS data to provide accurate distance and speed data.

For weight training, Coros offers a complete tool for training. The application allows you to programme workouts to be transferred to the watch (more than 200 exercises available to work all the muscles of the body, animations to learn the movements, possibility of indicating the equipment used, etc.). The watch manages the display of the exercises and the follow-up of the training. There is a muscle heat map in the application. For more details, see our test of the Coros APEX 2 and APEX 2 Pro watches)

Profiles are customisable from the application. Up to 6 screens can be displayed and up to 6 data per screen. Some data is not available for all sports, such as 3D distance which is available for trail running but not for running.

Data fields: effort pace, 3D speed, slope percentage...

The application offers a number of data fields that you can choose to display in the sports profiles. There is training data from the GPS and the optical cardio, and useful data for outdoor activities from the barometric altimeter. For some data, you can display instantaneous, average, max and lap values.

Sports functions: complete, especially for runners and trailers

In addition to the classic measurements (distance, speed, heart rate, etc.), the GPS 900 offers practical tools for training, measuring performance, evaluating the impact of training on performance and knowing how to dose your training to avoid overtraining.

Runners and trailers will find dedicated tools such as comprehensive running dynamics (see data list above), a running performance score, race time prediction over a 5k, 10k, half marathon and marathon, running power assessment at the wrist without an external sensor, a night mode for night runs, a metronome. It will also soon be possible to pair a Stryd sensor for more accurate running power measurements.

Runners who are not comfortable with power concepts will be able to view the exertion pace, a new metric that takes slope into account. The feature shows how fast you would be going with the same effort but on flat ground.

Simple workouts, including splits, can be programmed from the watch and complex workouts can be programmed from the app (which can then be transferred to the watch) for running, swimming, cycling and strength training. Complex workouts allow you to program sets of repetitions and set the intensity of effort according to heart rate, pace, power or cadence zones. The GPS 900 also allows you to store a training plan with a calendar display and the ability to start programmed workouts. Programming is simple and takes no more than a few minutes.

Programming workouts — You can program and follow workouts on the watch

Programming of workouts — Programming is done from the watch (simple workouts) or from the application (simple and complex workouts)

Coros offers a summary of performance on the watch (training load, fatigue level, recovery level, VO2max, etc.) with practical gauges to situate yourself without having to know the principles of training.

Alerts can be programmed based on distance, speed or pace, heart rate, running power or even nutrition alerts with an automatic reminder to feed yourself along the way.

The Evolab platform, available in the smartphone application, or the Training Hub, a new performance analysis platform accessible from a computer, display and exploit the watch's data with comprehensive statistics (see examples in the application section).

GPS navigation functions

The GPS 900 by Coros offers full GPS navigation functions but no mapping as on the APEX 2 series. Coros users will not be disoriented as the same functions are found on this Decathlon model.

The watch displays the GPS track (breadcrumbs) live. As on all Coros watches, there is no dedicated screen for this display in the profile. You have to go to the toolbox to display it (Map icon).

There is route tracking (breadcrumb) but no turn-by-turn guidance. The route must first be programmed from a third-party application before being sent to the watch to be stored. Coros does not yet offer a route creation tool but is working on it. Several routes can be stored in memory and a library built up for later use on other rides.

The feature can be enabled in the profile settings when starting the activity. The watch then displays 2 additional screens, one showing the route to be followed (in dark pink with chevrons indicating direction), the other showing the past and future altitude profile with altitude indications and progress (current position on the profile). Pressing the cogwheel displays the remaining distance to go. If you go off course (approx. 40 m), the watch gives an alert.

Past and future altitude profile allows you to situate yourself and dose your efforts well

The return to start function offers to return to the starting point by following a straight line (as the crow flies) or by retracing your steps from the recorded track. The watch indicates the distance remaining to be covered. If you have already retraced your steps, you can indicate the direction to follow (forward or backward).

In addition to these navigation functions, there is full altimetry data (altitude, vertical speed, slope) and useful widgets: compass, sunrise and sunset times, dawn and dusk, storm alerts and full tracking of local air pressure to anticipate weather changes. Coros offers sophisticated monitoring with different methods of pressure monitoring: sudden change, V-shaped evolution (decrease followed by an increase), comparison of the last 3 hours with the previous 3 hours for example. The internal thermometer allows you to measure the external temperature, whether it is the water in the mountain lake or in the tent during bivouac trips!

Unlike the APEX 2 and VERTIX 2, the GPS 900 does not have a pulse oximeter and therefore cannot offer an altitude mode with risk assessment for high altitude ascents.

Activity tracking and connected features

Daily activity monitoring

The GPS 900 is designed to be worn 24 hours a day, in addition to sport. Being light and comfortable to wear, it is easy to forget you are wearing it!

It offers the classic daily activity tracking functions (steps, distance, calories, activity time, continuous heart rate, temperature), counts floors climbed and tracks your sleep.

The sleep monitoring is limited to recording the start and end times of sleep and displaying the details of the different sleep phases (light, deep, REM/REM) and the awake times on a graph. To date, Coros does not provide a detailed sleep analysis or sleep score.

The data can be viewed on the watch in dedicated widgets and in the application. The display on the watch is slightly less detailed than that offered by the APEX 2 series. A single screen displays data on calories burned in a day, number of steps, activity time and number of steps climbed. There is no graph summarising this data over the week.

There are 24 hour graphs of heart rate and temperature. The jog wheel allows you to navigate through the graph to view the data recorded every 10 minutes in detail.

Connected functions

This model offers many of the same connected features as the APEX 2 and VERTIX 2, with the exception of the "Find My Phone" feature and the MP3 player, which are not included in this model.

There are the classic Smartphone notifications (emails, SMS, social networks, calls), control of a GoPro or Insta360 camera, heart rate broadcasting to a fitness device (home trainer, elliptical, etc.), data synchronisation with STRAVA or a Decathlon account. There is no possibility to control the music from your smartphone.

Regarding Smartphone notifications, it is not possible to respond with a text message. We also find the same anomalies as on the Coros models. Smilies are not supported. When a smiley, an audio message or a video is received, the watch simply displays the message "Searching for new messages" and you have to go to your phone to find out more. We would have liked to see an icon or a message indicating the reception of such media. Another concern is that it displays the same message (empty notification) for messages from people or Whatsapp groups placed in silent mode, which is quite frustrating.

The watch also benefits from automatic updates managed by Coros. The equipment manufacturer provides regular updates to add new sports profiles, improve certain functions or even create new ones and correct any bugs.

Autonomy

Decathlon announces a great autonomy for its GPS 900: 35 hours in sport mode (using the GPS alone) and 30 days in connected watch with heart tracking every 10 minutes (20 days in intensive use). In UltraMax mode (30 seconds of recording every 120 seconds), the watch has an autonomy of 80 hours during sport.

In practice, we were able to reach 25 hours for sport in multi-system GPS mode and about 28 days in the connected watch without doing any sport.

Count on about 4% of consumption per hour of sport and barely 4% in daily use with heart tracking every 10 minutes (10% for continuous heart tracking). If you wear the watch 24 hours a day and do 1 hour of sport per day, you will only have to recharge it every 12-13 days (or 7 days if you activate continuous heart rate monitoring).

	GPS 900		APEX 2
	Stated autonomy	Measured autonomy	Stated autonomy
GPS alone	35 h	Not measured	45 h
All GNSS	Not communicated	25 h	30 h
UltraMax mode	80 h	Not measured	Not communicated
Watch	30 d^(*)	28 d^(**)	17 d

GPS accuracy test

We tested the GPS accuracy of the GPS 900 by Coros in various satellite reception and weather conditions, in the city, in the forest and at high altitude. We tested the All systems mode (GPS, GLONASS, Galileo, Beidu) and the UltraMax mode (30 seconds of recording every 120 seconds). We compared the tracks, the total distances recorded, the cumulative distance versus time and the accumulation of tracks for a route covered several times.

Part of the tests were carried out in a small village where the satellite reception is not very good (narrow streets among stone houses). This location is a reference for all our tests.

Our tests confirm a very good GPS accuracy with even some surprises compared to the Garmin and Coros watches tested in parallel and which are however equipped with a dual frequency GPS.

Testing GPS in GPS mode with best accuracy

A good GPS watch must first and foremost measure the distance along the route accurately in order to be able to display a reliable speed or pace and of course a correct total distance.

The first observation is that the GPS 900 is very reliable. During our various outings, it displayed, throughout the course, a distance almost identical to that of the Coros watches tested at the same time. Here is an example (partly in town) showing almost identical distances at each moment! (this graph is produced by the comparison tool of sport-passion.fr).

The same was true in the forest, where satellite reception was less good (below):

In the village where reception conditions are poor, the GPS 900 (red line) sometimes does better than the multiband models. Here are 2 routes taken on different days.

GPS track in the city — •GPS 900 (all systems)•Garmin Fenix 7S Sapphire (satIQ)•Coros APEX 2 (all systems)•Coros APEX 2 Pro (multiband)
GPS test in the city - The GPS 900 shows a track that is sometimes better than multiband GPS watches (Click to enlarge)

Other GPS track in the city — •GPS 900 (all systems)•Garmin Forerunner 955 (multiband)•Garmin Forerunner 255 (multiband)•Coros APEX 2 Pro (multiband)
GPS test in the city : same route on another day (Click to enlarge)

The track is not perfect, with a few off-roads here and there, as on the left graph. But the same is true of other watches, like here on the right with the 2 Coros APEX 2 / 2 Pro models.

GPS Test — •GPS 900 (all systems)•Garmin Forerunner 255 (multiband)•Coros APEX 2•Coros APEX 2 Pro (multiband)

Here, the 4 successive road crossings (slots) are well recorded on the Garmin watches, a little less precisely on the GPS 900 and the APEX 2 Pro.

Here is another route where the GPS 900 track is a little off the track (the blue track of the Garmin Forerunner 255 is more accurate on this section).

GPS tracker recessed — •GPS 900 (all systems)•Garmin Forerunner 255 (multiband)

These recording uncertainties do not allow us to form a good opinion of the accuracy of the GPS positioning. A good way to check its reliability is to compare the tracks (in blue here) for a route taken several times and therefore in various conditions (weather, available satellites, etc.). The actual route is shown in red. The GPS 900 shines by its better accuracy than the other watches tested, in particular that of the APEX 2 Pro even though it is used in dual frequency GPS mode.

GPS test: overlay of several identical routes — •Real route•Recorded tracks (several trips made on different days)
GPS test: the same route made several times on different days

The same is true on this open section where the GPS reception is good. The tracks are well concentrated and the GPS 900 shows the best accuracy just after the Forerunner 255 and its multiband GPS. The Coros watches offer a more approximate track with some clear off-roads on certain courses.

GPS test: superimposing several identical routes — GPS test: the same route made several times on different days

Testing the Ultra Max mode

The Ultra Max mode, available with certain profiles such as trail running or running, increases the battery life by more than 2 times. The watch records the position for 30 seconds every 2 minutes.

The GPS 900 offers a much lower accuracy in this mode than the other Coros watches tested as can be seen in this graph (the actual path is drawn in black).

Testing Ultra battery mode — •GPS 900 (all systems)•Coros APEX 2 (all systems)•Coros APEX 2 Pro (multiband)•Real path
Testing GPS in UltraMax mode

Testing the GPS during breaks

Like other Coros watches, the GPS 900 provides a clean track during breaks (without using the auto-pause) unlike Garmin watches, even those with dual frequency GPS (track in blue on the graph). Coros seems to detect, thanks to the accelerometer, the relative immobility of the watch to eliminate obsolete GPS records.

In conclusion, the GPS 900 by Coros offers an excellent GPS that has nothing to envy to the recent APEX 2 models. Even if the track is not free of small deviations here and there, it is globally good and even seemed to us more accurate on average (identical route done several times) than that offered by the multiband watches tested in parallel. The distance measured along the course and the total distance are very much in line with those of the Garmin and Coros watches.

Altimeter accuracy test

The GPS 900 altimeter is very accurate as can be seen from the graphs below. The first two were recorded on the same course at low altitude, the last one at higher altitude (2000 meters). During the different tests, the GPS 900 and the Coros watches (APEX 2, APEX 2 Pro) showed almost identical tracks and also very close or even confused with the Garmin watches tested in parallel.

There is sometimes an initial discrepancy of a few metres between Coros watches (GPS 900, APEX 2, APEX 2 Pro) despite manual calibration of the altimeters. The Coros engineers explained to us that the GPS is used for altitude measurements (and the altimeter for altitude differences) and that the watch regularly performs an auto-calibration from the GPS. The altitude set at the start can therefore be adjusted by the watch software. When the signal is poor, the altimeter is used as a reference. The altimeter is also regularly autocalibrated from the GPS to correct for variations in atmospheric pressure. The user can therefore theoretically set off without calibrating his watch, unless he knows in advance that the GPS signal will be poor at the start. On the other hand, the altimeter of the GPS 900 (like any other Coros watch to date) cannot be calibrated during the activity.

On the same course a few days later, the two Coros watches once again offer an almost identical route. The Garmin route is a little bit different, as the watch was not calibrated at the start.

On this high altitude course (more than 2000 metres), the GPS 900 offers an almost identical course to that of the other two watches (5 metres difference at the most).

The altitude totals (vertical drops) are also very reliable with values close to those of the GPS 900 and the other watches tested. The measurements are almost identical from one outing to another on the same route (table below).

	GPS 900	APEX 2 / 2 Pro	Forerunner 255	GPS 900	APEX 2 / 2 Pro	Forerunner 255
Sortie	Asc+	Asc+	Asc+	Asc-	Asc-	Asc-
1	178	181	178	93	95	99
2	171	172	173	171	172	171
3	171	174	172	167	168	171
4	165	169	176	162	166	175
5	171	174	175	169	172	171
6	171	175	168	170	171	171
7	167	169		165	165
8	169		169	170		175
9	173		170	169		172

Optical heart rate monitor test

The GPS 900 is equipped with the same optical cardio as the old Coros APEX and it shows. Its accuracy is not exemplary, with sometimes quite large discrepancies with the data from the Garmin HRM Dual chest belt worn for the tests. This can be seen here on this graph and also in our other tests.

The watch does quite well during some accelerations (minutes 25 to 28) even if the track is not perfect.

In comparison, the APEX 2, worn on the other wrist, shows much better accuracy in all our tests, probably due to its new sensor with 10 LEDs and 4 receivers.

The average heart rate recorded also shows varying degrees of variation (only 2 bpm in the test below but up to 14 beats in other tests).

It is important to point out that we would have needed to tighten the strap of the GPS 900 by one more notch, as it was a little too big for our 15 cm circumference wrist. The results may indeed be incorrect if the watch is not perfectly stuck to the skin and immobile. For an optimal result, you can always change the strap, for example for a nylon model better adapted to thin wrists and more appropriate for this type of measurement.

The data can also vary greatly from person to person depending on skin type, hairiness, external temperature, sweating, etc. Our tests are therefore very subjective and we do not guarantee their reliability. They allow you to get an idea and to compare the results with those obtained under the same conditions with other watches. If you are looking for the best accuracy, we recommend using a chest belt.

Coros application, Evolab and Training Hub

Coros offers a Smartphone application for all daily sports and activity data and a dedicated performance analysis tool, the Evolab platform.

Recently, there has also been a web-based platform, the Coros Training Hub, which can be accessed from a computer. This performance analysis tool is intended for athletes and their coaches, each of whom has a dedicated space.

The application, which is simple to use, can be improved, but Coros is constantly working to improve it. An itinerary creation tool will be available very soon.

Here you will find a more detailed description of the Coros application, Evolab and Training Hub>/test-material/revue-detaillee-et-avis-coros-apex2-apex2pro.php#application-coros>description of the application, the Evolab platform and the Training Hub>##.

graph — Graphs can display multiple curves at the same time to allow full analysis of the output

Test conclusion - Our opinion

Its elegant and robust design is suitable for both sports and everyday use. The materials are of good quality despite the price (in comparison, the PACE 2, which is only slightly cheaper, is all plastic). In terms of reading comfort, we even preferred the GPS 900 to the APEX 2 because of its more transparent and less reflective glass than sapphire.

The sports and GPS navigation functions are excellent. Apart from the cartography, which is absent on this model, we have almost the same functions as those offered by the APEX 2 series, models that are fairly high in the Coros range. To find such functions on a watch at less than 250 € is exceptional!

This model is complete but without frills to offer the best price: no pulse oximeter, no ECG, no MP3 player. This is what users who can't afford to pay much for a watch, especially for features they don't use, are looking for.

Finally, this outdoor watch offers an accurate GPS and altimeter, which is essential for sportsmen and women who are looking for the best precision for training and competitions. This avoids unpleasant surprises such as a higher than expected summit or a marathon finish at more than 42.2 km!

The only downside was that the old generation optical cardio did not seem to be up to the task. And yet, the relevance of the performance analyses depends on its precision. But as we said, the strap was a little too big for our wrist, making measurements more delicate. In any case, the most reliable optical wrist heart rate sensors are never perfect. For the most accurate measurements, especially for training, it is best to use a chest strap.

Another point is that the strap is a bit big for small wrists. For a wrist of less than 15 cm in circumference, it would be better to opt for a nylon Coros bracelet, thus adding 30 € to the price of the watch.

Finally, thanks to its unbeatable price for the functions offered, this model becomes accessible to sportsmen and women who did not have the financial means to acquire a good outdoor watch. Decathlon has made the right compromises to offer an unbeatable price without compromising the quality of the watch's materials, measurements, autonomy and functions. At less than 250 €, this outdoor watch, which can also be used for triathlon and running, seems to us to be a really good deal. It is also an excellent compromise for people who are interested in the Coros brand but cannot find an affordable outdoor model in the new Coros watch range.

Price and availability

The GPS 900 by Coros is available now on the Decathlon website and in most of the group's shops for 249 €. It comes in a single colour, black, and a single strap size but can be replaced by any other Coros 22mm strap (nylon strap for example)