Sigma Rox 12.0 review

Sigma launched the Rox 12.0 with the intentions of taking on the current crop of top-tier cycling computers. Not especially known for this level of product, Sigma might surprise some with the performance of its full feature offering.

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The Device

The Sigma Rox 12.0 feels, looks, and operates much like a smartphone. The sizing fits into your hand like a phone and the Android system (although heavily modified) operates as a phone. The Rox 12.0’s aesthetic design is not the sleekest and certainly lags behind the style and feel of a Garmin Edge devices. An aesthetic considering is the black rubber casing which can be swapped out for another colour (perhaps to match your bike).


Sigma Rox 12.0-2.jpgThe Rox 12.0 is charged via a USB cable. There is also supports for an SD card.

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Measuring 59 x 115 x 17 mm, the device is large. Our test unit weighed 125 grams, making it slightly larger than Garmin’s Edge 1030 but about on par in weight. The bigger Rox 12.0, however, has a smaller 3-inch screen compared to the Edge 1030’s 3.5-inch display but larger than the Edge 820’s 2.3-inch screen.


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The Sigma Rox 12 dwarfs a Garmin Edge 520 (it's all we had). A better comparison would be Garmin's Edge 1030 device which is only marginally smaller.



The bigger and heavier a device gets, the more vital a secure mounting becomes. Our demo unit arrived without mounts. But I’m told that the base kit arrives with an out front mount and o-ring handlebar/ stem mounts. The Rox 12.0 is also compatible with Garmin-type quarter turn mounts and I used the o-ring version to mount the Rox 12.0 to my road and mountain bike during the test.


On the road bike, I mounted the Rox 12.0 onto my road stem where it sat firmly in place. It just squeezed in between the steerer and handlebar with a 110mm stem. There was no chance of fixing the Rox to the stem on my mountain bike, so the handlebar it was. Here the Rox 12.0 was free to rock back and forth where it eventually flipped the device around to the underside of the bar. I would recommend using the out front mount for mountain biking.



Touchscreens have been a bit hit-or-miss on bike computers, with some manufacturers suffering from poor implementation, but the Rox 12.0 gets it right. The screen was largely responsive to touch even with gloves on. The Rox is designed to sense wet conditions and adjust the screen to these conditions and I found no fault when the screen was damp. The Rox 12.0 also has six buttons. Side buttons for switching the data screens left or right, a confirmation button in the bottom middle with start, lap and stop buttons on either side. It’s a hybrid system that works well with the buttons helping perform common tasks (although not offering full control of the Rox 12.0 and its settings).


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The home screen.


You can imagine that there was a chance of the Rox 12.0 becoming a bit overwhelming to operate with all those input options but Sigma has done well to make the interface naturally intuitive. Swiping the top edge down drops a screen where you can adjust a bunch of settings, including screen brightness, access navigation functions, turn on Strava Live segments. Dragging the bottom edge up brings up a screen with recent routes. Swiping left or right brings about extra settings or, during an activity, changes between the data screens. The side buttons work best mid-ride to change data screen where a screen swipe would be more fiddly. When adjusting settings off the bike with the device in your hand, swiping the screen with your thumb is a more natural movement.


This Sigma has a number of screen layouts to display ride data. You can cram all your data on one screen, share it with a map, show elevation graphs, the works. The data fields are also easily changed on the fly, simply long press on the data field you want to change and a list of replacements will appear. There is just about everything to please everyone when it comes to data displays. I had no visibility issues with the screen, riding in broad daylight, rain and the dark, it was always clear to view.


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Sigma Rox 12.0-19.jpgCustomizing data fields was a pleasant task on the Rox 12.0.


The Rox 12.0 communicates with the outside world via WiFi or a USB cable connection to a computer. There is no support for Bluetooth connectivity to a phone although you can fire up a WiFi hotspot on your phone. This means no mid-ride message or calls notifications, nor any live tracking.


The Rox 12.0 supports direction connections to third-party services. Off the bat, Sigma has Strava, TrainingPeaks, GPSies, and Komoot apps built in. Sigma does include a Sigma Cloud service and the Sigma Data Centre software. The latter allows you to dig into your activity data, change settings for your device (like screen layouts), and serve your activities to third-party services. Due to my favourite apps being supported on the device, I did not feel the need to venture too deeply into the Sigma ecosystem.


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The Rox 12.0 connects to all the sensors you would expect from a high-end bike computer through ANT+ and Bluetooth Smart, including heart rate, speed, cadence, power meters, electronic shifting, and even e-bikes. You can set up Sport Profiles for different riding types, road, mountain, e-bike, etc. Each profile will store the desired sensors meaning that you can switch bikes and the attached sensors with relative ease. The profiles also store other preferences such as data screens.


The Rox 12.0 updates over WiFi. I received one firmware update during testing. It fixed a list of minor bugs and added some functionality but the main purpose was to further improve the turn-by-turn notifications on navigation. It is always reassuring to be receiving updates from the manufacturer, it's a sign that they haven't simply released a product to forget about it.


Navigation and workouts

The most compelling reason to buy a Rox 12.0 is the comprehensive navigation package.


Sigma bases their maps on Open Street Map data for the Rox 12.0. This means that all maps are available without charge for all regions. When connected to WiFi, it takes a simple selection from a list to download a map for a region. The device should come pre-installed with the region it was sold in. I found the Open Street Map data to be reasonably accurate and very comprehensive in the Cape Town region even including many off-road mountain paths and trails. The maps also include details like points of interest. I did spot some outdated information, such as Lister's Place in Tokai which has been closed since the fires a few years ago and Epic Bike shop which has moved and changed name.


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Sigma offers an impressive number of options to commence a journey. Of course, you can also load routes through the supported third-party services like Strava and Komoot. Firing up the navigation menu, here are the options that greet you:
  • Directions to an address
  • Find a Point Of Interest
  • Draw a route on the map
  • Select a point on the map
  • Re-ride a recent route
  • Select from one of your favourite routes
  • Trace the route of previous activity
  • Enter GPS coordinates
As I mostly rode routes that I knew during testing, I loaded my commute and regular morning road loop as routes from Strava. I was impressed with the level of detail displayed on the map with the colour screen thoughtfully used to differentiate elements on the map. When moving, the map zooms out, giving you a general sense of where you are. The map zooms for detail as you come to a turn so that you make the correct turn. The rider marker on the map was accurate and without lag, leaving me without any doubts as to which path to follow. Take an incorrect turn and re-routing is snappy without any annoying recalculations.


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Drawing your route and allowing the device to find the most suitable route was one of the more interesting navigation methods.


The only blip occurred when coming to a halt at intersections. The Rox 12.0 seemed to forget the direction it had been travelling and the avatar on screen spun around aimlessly making your next turn somewhat confusing should you not have been paying attention leading to the stop. Otherwise, the navigation on the Rox 12.0 is superbly functional.


The Rox 12.0 packs the smarts to create custom workouts which you build on the device. You can set phases to build a complex workout. Each phase includes the duration, a goal (heart rate, cadence, power, etc), and a number of repetitions. There was no obvious method of importing a workout made externally (from Training Peaks for example).


A quirky feature is the eating and drinking reminder. I'm fond of my ride snacks, so not something I've often neglected but I do recognise that it can be an afterthought for some riders and having regular reminders to stay topped is one way to remove a complication come race day.



The Sigma Rox 12.0 retails for R8,995. The two devices that are most comparable to the Rox's navigational features are Garmin's flagship Edge 1030 which retails for around R11,999 and the Edge 820 at R8,899. Wahoo and the other Edge devices, while excellent considerations, do not offer as broad a navigational experience. The Rox 12.0 is in the ballpark in terms of pricing but I'd like to see it come in cheaper than the Edge 820 (which seems to be the case in Europe) to really bring the fight to Garmin.


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The Sigma Rox 12.0 makes a strong challenge against its established competitors. The navigational feature set is impressive while the touchscreen is one of the best I've used on a bike computer. Sigma does not offer all the bells and whistles that you might get from an Edge 1030 which, depending on your needs, may be a deal breaker. But if you're after an intuitive user interface, great navigation, and a touchscreen that works in all conditions, then the Rox 12.0 could be your next bike computer.



DieselnDust, Nov 12 2018 07:38

spent a few days with a demo model. WOW! Garmin has a real contender for it crown.

Not supported by Discovery though but its a superb unit!

Rocket-Boy, Nov 13 2018 09:00

I honestly dont like the idea of an android powered bike GPS.

It leaves too many other variables out there for future updates and will always be more limited than an OS designed specifically for a device.

Marsh00, Nov 14 2018 01:48

Reminds me of a Blackberry ....

DieselnDust, Nov 14 2018 02:49

looks more like a Nokia and it just works and works very very well.