At road.cc every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.
Good scores are more common than bad, because fortunately good products are more common than bad.
The Sigma Rox 12.0 Sport Set GPS is an impressive bundle, including an easy to use head unit with fast mapping plus the addition of cadence, speed and heart rate monitors. Maps are included and you get all the possible connectivity you could need.
For many years Garmin had the lion's share of the GPS market, but recently we've seen other brands such as Wahoo, Lezyne, Hammerhead and others nibbling away at its dominance. Sigma needs to be added to list now too.
I've only got one little niggle with the Rox 12.0 and I'm going to get that out of the way first.
The head unit is pretty big – 114 x 59mm – a similar size to the Garmin Edge 1030, but the screen doesn't use all of that real estate, being just 65 x 40mm.
It's a touchscreen-based system so I don't see why Sigma has needed to go for the buttons at the bottom for stop/home/start/lap – just incorporate them into the screen. It would make the whole thing much more user-friendly, especially when reading the map.
Right, let's crack on with the good bits.
The Rox 12.0 is simple to use and set up. You get a little quick start booklet in the box if you need it, and there are full instructions on the website. With a bit of screen tapping, I had it pretty much all sussed without needing to consult either.
Turning it on for the first time, you need to add the usual metrics about yourself plus there are a selection of sport profiles that you can use, including road bike, mountain bike, e-bike, and indoor cycling.
You can add to these and customise them for various bike setups, to include wheel and tyre sizes plus weights. I had them set up for different test bikes, especially as I wanted to see different info for road and gravel.
In the box you'll find a joint speed and cadence sensor with a couple of magnets to get everything talking to each other. It's a bit old school, but fitting the sensor to the chainstay with the supplied cable ties only takes a few minutes.
There is also a heart rate monitor with chest strap.
The Rox supports Bluetooth, ANT+ and wi-fi so you can now go through the pretty painless exercise of pairing all of your other devices and accessories. It was all done in a matter of minutes, and allows you to link directly to Strava, Komoot, Dropbox, GPSies and Training Peaks.
For mounting the unit to your bike you get a few options. There are a couple of basics mounts that just cable tie to your stem, or there is an out-front bar mount and it's a pretty solid affair. Ideal considering the size and 127g weight of the head unit.
The mount is Garmin-compatible and the cool thing is that in the package you also get a GoPro mount to fit under the head unit; these are normally optional extras.
You get six screens to show the data required for your ride, ranging from speed to time, altitude, cadence, heart rate, power, temperature and so on. You can see a full list in the test report section below, but pretty much every field you think you might need is covered.
Depending on what data you select, the screen adapts to the size 'cube' it thinks it needs. For mapping and elevation graphs, for instance, it will give a larger proportion of the screen.
To get the best out of the mapping, I gave that a complete page out of the six all to itself.
For navigation, the Rox 12.0 uses OpenStreetMap and it is quick. Turn by turn instructions are highlighted well in advance, and the Sigma has some neat little touches like Draw my Route where you can actually sketch a rough guide over the map with your finger and the device creates the route on the closest rides.
Alongside Address and POI there is also a Point on Map option, where it kind of does what it says: you pick a point and it gets you there. You can choose the quickest route, off-road, the most scenic, whatever you want really.
As you'd expect, you can upload routes too that you've created elsewhere. You'll get estimated finish times and remaining distance and the like. It really is a clever little device.
One thing I was very impressed with is how quickly the Sigma locks on to a GPS signal. You are literally looking at 30 seconds or so, and that is from inside the house before you even set foot outside.
While riding, you can scroll through the pages via the touchscreen or use the up and down buttons on either side of the unit.
Turning the device on and off is controlled by a single power button, which you can also use to lock the screen.
You've also got the choice of controlling backlit times and whether you want it in day or night mode – a black or white background, basically. In all conditions I found the screen easy to read.
Other features include having alerts to make sure you eat and drink, plus you can tap into Strava's Live Segments if that's your thing.
Riding an e-bike? No worries, you're covered there too. The Rox 12.0 is compatible with Shimano's STEPS E5000, E6100, E7000 and E8000 (with appropriate wireless unit) and can show you battery life in relation to your riding style and what sort of range you can expect.
I never had a single issue with the performance of the Sigma throughout testing, which is more than I can say for my Garmin 810 that it replaced.
The Garmin crashed regularly, especially in the heat – anything above 25°C would see it switching itself off, and following routes over about 50 miles would often see it go a bit squiffy.
No such issues here with the Rox 12.0. I've followed 100-mile routes with turn by turn instructions without a problem, and the heat hasn't been a concern either.
Neither has the rain. This unit has seen some pretty horrendous conditions culminating in a four-hour ride in torrential downpours which it just shrugged off. Sigma says that it can detect rain and blocks the display from being impacted from the drops – clever, eh?
The micro-USB charging port is hidden behind a very secure rubber cover to keep the elements out and it does the job brilliantly.
Next door you'll find an SD card slot for boosting the memory capacity, although you do get a pretty impressive 8GB to start with.
Battery life is good too. Sigma claims around 16 hours but as with all electrical devices that's best case scenario – warm temperatures and nothing turned on basically.
With everything switched on, wi-fi, Bluetooth, the lot, I was easily getting around 12 hours when having the backlight set at two minutes after each touch of the screen.
Apart from being able to upload everything to Strava et al, Sigma also has its own data platform via the Sigma Link App and the Data Centre.
It's pretty basic in the grand scheme of things but it does give you all of the data recorded from your rides. In all honesty I didn't really bother with it much, but it is there if you want it.
Looking at the overall package, I'd say the Rox 12.0 offers pretty good value for its £349 price tag.
Reading through Mat's review of the Garmin 1030 that I linked to further up the page, it looks as though the Sigma covers the majority of the same bases but without the faffing.
I haven't had a single issue with this unit. It's done everything I've asked from it, and if I'm completely honest I probably won't use half of its capability in everyday riding.
Dave recently tested the £388 Hammerhead Karoo and really liked it. I think the Sigma has quite a few similarities, and on the whole I'm really impressed.
If you want a bit of colour coding you can also buy different cases to complete the look.
The Sigma Rox 12.0 does everything I want from a computer and more. The more I've used it, the simpler it has become to operate, and the fact that I know it is going to be so reliable really takes the pressure off on long and unfamiliar roads. If the screen was just a touch larger then I couldn't fault it.
A brilliant GPS unit that provides all of the data you need without faff
If you're thinking of buying this product using a cashback deal why not use the road.cc Top Cashback page and get some top cashback while helping to support your favourite independent cycling website
road.cc test report
Make and model: Sigma Rox 12.0 Sport Set GPS computer
Size tested: 3in display
Tell us what the product is for and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Sigma says, "The ROX 12.0 brings navigation and training to a whole new level. The GPS bike computer is loaded with new map functions, numerous training features and packed into powerful hardware. Explore the possibilities and discover the ROXstar in you!"
I reckon it is a cracking little unit that covers pretty much every base you are likely to need.
Tell us some more about the technical aspects of the product?
Direct link to apps of third-party providers via WiFi - Strava, komoot, GPSies, TrainingPeaks
Direct link to the SIGMA CLOUD via WiFi - SIGMA LINK App, DATA CENTER
Heart rate functions
Intensity zones (graph)
% HR max.
Maximum heart rate
Minimum heart rate
Zone bars (heart rate / CAD / SPD) (graph)
Current heart rate
Heart rate graph
Average heart rate
Average % of HR max
Maximum altitude in lap - / Automatic Lap
Maximum heart rate in lap - / Automatic Lap
List of laps - / Automatic Lap
Elevation gain in lap - / Automatic Lap
Calories in lap - / Automatic Lap
Distance in lap - / Automatic Lap
Maximum power in lap - / Automatic Lap
Maximum speed in lap - / Automatic Lap
Pedaling index in lap (%) - / Automatic Lap
Pedaling time in lap - / Automatic Lap
Time in lap - / Automatic Lap
Number of laps - / Automatic Lap
NP®* in last lap / automatic lap
Normalized Power®* in current lap - / Automatic Lap
Average speed in lap - / Automatic Lap
Elevation loss in lap - / Automatic Lap
Average heart rate in lap - / Automatic Lap
Average rate of descent in lap - / Automatic Lap
Average downward slope in lap / automatic lap
Average cadence in lap - / Automatic Lap
Average altitude in lap - / Automatic Lap
Average balance in lap - / Automatic Lap
Average power in lap - / Automatic Lap
Average rate of ascent in lap - / Automatic Lap
Average power in last lap - / Automatic Lap
Connectivity - WiFi, ANT+, Bluetooth Smart (Rotor Power)
Weight - 125 g
Battery life - Up to 16 hours (in energy saving mode Up to 40 hours)
Dimensions incl. holder - 59 x 115 x 17 mm
Display size - 3 inches (240 x 400 pixels)
Supports power sensors
Compatible with Shimano Di2 / SRAM eTap / Campagnolo EPS V3 Interface
Battery - Lithium-Ion rechargeable battery
Water resistance - IP67
Color display - with Touchscreen
Status functions - GPS Accuracy, Battery capacity (in %), Sunrise and sunset
Maximum slope downhill
Maximum rate of descent
Rate of ascent in m/min
Maximum rate of ascent
Incline in %
Training time uphill
Training time downhill
Maximum incline uphill
Average speed uphill
Altitude profile graph
Average rate of ascent
Average incline uphill
Average speed downhill
Average slope downhill
Average rate of descent
Distance to destination
Turn-off notifications (visual and acoustic)
Time to destination
Estimated time of arrival
Pedaling index (%)
Power in % FTP
Normalized Power® (NP®)*
Power in KJ
Rotor Power (OCA, OCP, average OCA, average OCP, graphic)
Training Stress Score® (TSS®)*
Torque effectiveness (--% / --%)
10 sec - Average balance
Intensity Factor® (IF®)*
30 sec - Average balance
3 sec - Average power
3 sec - Average balance
10 sec - Average power
7 Power target zones
30 sec - Average power
Current power in watt/kg
Maps and memory
Tracks - Unlimited
OSM map preinstalled - Europe
Further countries available free of charge - Globally
Accepts memory cards - max. 128 GB microSD
Transfer of tracks (.GPX) - Micro-USB
Transfer of tracks from DATA CENTER - SIGMA CLOUD (WiFi), Micro-USB
Preferences for types of road / pathways can be defined - Major Roads, Unpaved Roads, Cycle Roads
Direct access to tracks of third-party providers - Strava, komoot, GPSies
9 routing options - Address, Draw my Route, Point of Interest, Point on Map, Recent, Favourites, Tracks, Activities, Coordinates
3 suggested route types per routing - Suggested, Easiest, Shortest
Templates for training views - 30
Training values - 150
Strava Live Segments (with premium account)
Preinstalled sport profiles - Road Bike, Mountain Bike, Cycling, Indoor Cycling
Individually configurable training views - Up to 6 pages
Interval training (workouts)
Individually adjustable sport profiles - Unlimited
Graphic data evaluation
SIGMA LINK App - Smartphone (iOS / Android)
Memory - ROX 12.0
DATA CENTER - PC / MAC
Tell us how the product performed overall when used for its designed purpose
Covers everything I would want from a GPS unit.
Tell us what you particularly liked about the product
It's simple to operate and it works without issue.
Tell us what you particularly disliked about the product
I'd like a bigger screen size.
How does the price compare to that of similar products in the market, including ones recently tested on road.cc?
I reckon it's priced very well indeed considering the package it delivers, especially against something like the Garmin 1030 which is £499.99.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your overall score
I came into this review admittedly with quite relaxed expectations of the Sigma, but it has really proved me wrong. It delivers everything I need and plenty more. If the unit could use more of the body for a bigger screen then it would become pretty much hard to fault.
About the tester
I usually ride: This month's test bike My best bike is: B'Twin Ultra CF draped in the latest bling test components
I've been riding for: Over 20 years I ride: Every day I would class myself as: Expert
I regularly do the following types of riding: time trialling, commuting, club rides, sportives, fixed/singlespeed
With 20 years of road cycling and over 150,000 miles in his legs it's safe to say Stu is happiest when on the bike whatever the weather. Since writing his first review for road.cc back in 2009 he has also had a career in engineering including 3D-CAD design and product development, so has a real passion for all of the latest technology coming through in the industry but is also a sucker for a classic steel frame, skinny tyres, rim brakes and a damn good paintjob.
His fascination with gravel bikes is getting out of control too!