Sigma Rox 12 Review ▷ Cycling GPS Bikenav

Sigma Rox 12 Review

The main thought that stood out in my research for this Sigma Rox 12 Review was “Why don’t I see these everywhere?“. The Rox 12 is a really sweet device whose numerous positives vastly outweigh the infrequent negatives.

Sigma Rox 12 Review

The Sigma Rox 12 is a mid-sized, BIKENAV with some good features for STRAVA officianados and performance cyclists alike.

Here’s the review summary with LOTS of detail afterwards. Enjoy.

  • Price - 90%
  • Apparent Accuracy - 85%
  • Build Quality & Design - 85%
  • Features, Including App - 90%
  • Openness & Compatability - 90%


Sigma Rox 12 ReviewThe Sigma Rox 12 is yet another good bike nav that seems to fall under many people’s radar.

YES, the Rox 12 is highly functionally-competent but it has a few rough edges both in terms of its looks and in terms of how the whole platform gels together. Nevertheless, It is definitely worth considering, especially if you think Garmins are too highly-priced. The Rox 12 gives you a lot of bangs for your buck, just in terms of the sheer number of features and quality construction.

If you need to navigate a LOT or if you like to use STRAVA’s routes & segments then the Rox 12 becomes even more compelling. Whilst it does have very many features for the performance athlete, I suspect that many of those kinds of potential buyer will look instead at a Wahoo Elemnt or Garmin because of their support for less widely-used features like 3rd party training platform integration, smart trainer control and the flexibility provided by Garmin’s CIQ apps.

But most of you are NOT performance athletes so why would you choose the Rox? Maybe the global maps might tempt you or maybe you would prefer to get a few more stats from the manufacturer’s analytics platform than Garmin?




  • Impressive navigation support – ONE OF THE BEST
  • Responsive navigation engine eg quick and sensible re-routing directions when off-course – ONE OF THE BEST performing
  • Well thought-through STRAVA integration and features – ONE OF THE BEST
  • Generally good touchscreen – ONE OF THE BEST performing
  • Reporting and analysis platform is better than Garmin Connect but still in need of improvement
  • The included Barfly Out-front+GoPro mount is a nice touch for commuters


  • No smartphone connection (but workouts are sync’d back to the smartphone app to view and mobile hotspots are supported as a workaround). No in-ride notifications as a consequence.
  • No 3rd party training plan integration
  • Generally responsive but sometimes less so.
  • No FE-C trainer control
  • No ANT+ RADAR/Light support
  • No popularity routing
  • Cannot use own maps

Sigma Rox 12 ReviewBackground

The Rox 12 was released in Spring 2018 and represents the start of another generation of bike tech from Sigma Elektro GmbH (Sigma Sport). You may have readother outdated reviews, this review is written a year on (Oct 2019) and so bugs will have been fixed and new features added.

Previous generations range from their basic ‘BC’ models through to the Rox 7 and Rox 11 GPS models that are still sold. But the Rox 12.0 is a very different device and along with the recent, value-for-money Sigma iD.TRI watch, I see a company that has a cunning plan to improve its market position in several areas.

Rox 12 Impressions & Overview

Let’s start with a comparison to similar bike navs. Here you can see that the Rox 12 is mid-sized but unusually more elongated than the others, perhaps better suiting it to showing more of the upcoming route when navigating as well as making it fit better in your palm when carrying it. There is a lot of ‘bezel’ compared to the screen size and the screen area itself is not dissimilar to the Karoo and Polar V650 despite the different shape.

Sigma Rox 12 Review

It feels solid & well-made. There are 6 buttons and a touchscreen and whilst the buttons don’t look like they will work too well, they’re actually pretty good. Also surprisingly good is, at least superficially, the touchscreen.

Sigma Rox 12 Review


Sigma Rox 12 Review

Sigma Rox 12 Review

Almost equally, you can use the buttons or touchscreen to navigate around the device. There are, however, exceptions which require the touchscreen like the swipe-down screen and when choosing a specific route from several presented on the screen.

Sigma Rox 12 Review – Unboxing & Setup

Sigma Rox 12 ReviewI don’t usually spend too much time on this section but, for once, it’s worth pointing out that you also get a solid, Garmin-compatible out-front mount with Go-Pro underside adapter, a stem mount, a tether and the more expensive bundle also has a dual-band HRM and dual-band speed+cadence sensor thrown in for good measure.

The mount and all the accessories are well-made, indeed the HRM strap looks identical to an earlier Polar model. It’s a nice touch that the HRM broadcasts over BLE and ANT+.

The Sigma app does not work for setup with the Rox, so changes to Sports profiles and sensor connections are not possible on the app and can instead be completed on the Rox. Or profiles settings can be made on a computer via Sigma’s DATA CENTER.

Sigma Rox 12 Review

Superficially you will find that a ‘normal’ training or commuting setup with the Rox 12 is similar to many other devices. It’s also well-functioned for outdoor usage and could probably could be classed as a ‘performance’ cycling computer rather than just a BIKENAV.

You can create lots of sports profiles with up to 8 pages per profile (plus lap pages) and can have up to 10 data fields per page. Data fields are usually numeric but also include MAP and WORKOUT PROGRESS graphics.

Sigma Rox 12 ReviewA test that I use to assess if a device takes performance usage seriously is that it can display a “last lap NP” mainly because in order to be able to do that several other things also need to have been implemented like power meter support and FTP/power zone support as well as a ‘bit of thought’ being applied in the design process. Also, by noting support for ‘last lap NP’, then you’ll almost certainly have IF and TSS too. Of course, if you have ‘last lap NP’ then you will also have ‘lap NP’ 😉 YES, the Sigma Rox 12 passes this test with flying colours!

Indeed if I also told you it supported Rotor’s display of OCP and OCA for eliptical chainrings then you may well be even more impressed…if you knew what I was talking about! (It’s a little like Garmin’s “Power Phase” metrics).

Sigma Rox 12 Review
Most sensors supported – notably missing is VARIA LIGHTS/RADAR

In ‘normal’ usage, the Rox 12.0 is comprehensive in what it offers. I’m sure a basic data metric or two are missing but there are more than enough data metrics for me, although perhaps the one thing that IS missing would be more aesthetic dials, graphs and other graphics eg a FUEL GAUGE display for HR; a graphical indication of which gears Di2 has put you in; and a prettier elevation profile.

General Training Usage

I’ll cover specific training scenarios in a minute but once you have the Rox all set up, you will find that the overall quality of workout-based interaction with the Rox 12 is good.  The buttons are sufficiently easy to press and the touchscreen seems to almost always work and is very responsive as is the general interaction with the Rox 12, although sometimes it is slow to load longer routes (eg 100km). If you don’t like touchscreen then most things seem possible with the buttons. There is audio feedback too and that perhaps could do with being a bit louder but it’s alright.

Other than that, it’s a good bike computer. It does the usual stuff.

Navigating on the Sigma Rox 12

The full routing offering from Sigma is impressive and probably as complete as a high spec Garmin Edge 530/830 although not as pretty-looking as Hammerhead’s Karoo.

The first thing to remember that differentiates the Rox 12 from some competitors’ products is that the Rox 12 has ROUTING INTELLIGENCE with a real onboard map with a Digital Elevation Model (DEM) built-in. But in addition to an understanding of hills, named roads and junctions, it also has further routing intelligence, presumably via map layers, that enables it to give you routes appropriate for your current cycling activity type eg MTB, Hybrid, Road and so on.

Rox 12 knows what a junction on a trail “is” and can give you turn-by-turn (TBT) instructions.

The Rox 12 gets you from A to B in 8, yes eight, different ways.

  1. Street – Navigate to a street
  2. Draw – Create a route on the Rox 12 with your finger. It snaps to the roads and off you go – it works, it’s clever but it is tricky to use.
  3. POI –
    • Local POI – navigate to a POI near you eg a Train Station or a Cafe.
    • Remote POI – navigate to a POI to near somewhere else
  4. Map Point – pan, zoom and select a single point
  5. Recent – repeat a recent navigation of any sort
  6. Favourite Point
  7. Pre-loaded route/track
  8. GPS co-ordinates

Sigma Rox 12 ReviewBut it’s even clever than that and there are many subtleties to some of the methods of navigation. When the Rox creates a route it always seems to use roads or trails and never ‘as the crow flies’, which is fine I guess but for all those navigations you can choose the shortest or easiest routes there and you can change the priorities given to cycle routes, major roads and unpaved roads. You can reverse a route or your current journey, in order to get you home. When you choose to follow a route, you are prompted to navigate to it and, cleverly, that can either be to the start of the route or the nearest point of the route.

If you are grabbing a route file from somewhere else then you might use your routes on one of the connected services, namely STRAVA, KOMOOT or GPSies, each of which has biases to certain types of public routes that you can grab. I’d like to see integration with RidewithGPS too.

Handily, you can load a route using the ‘old skool’ drag and drop method onto the TRACKS folder on the Rox but you’re probably best, instead, using the Sigma software.

Sigma Rox 12 Review

The only major omission is a big one and that’s POPULARITY ROUTING.

With no smartphone link I can’t see how any form of live popularity routing will be possible whilst leveraging a 3rd party service like Google Maps, nor will Sigma have enough of their own global usage data to truly create a truly popular route for you to follow. You can create a popularity route offline of course – just create a free Garmin Connect account and download a gpx file from there…super simple, there are straightforward ways to grab a Google Maps route URL and convert to a GPX file too – use one of the free online conversion tools for Google Maps (you can use Hammerhead Karoo’s portal for that too)

Routing – Follow a Route

Generally, the routing experience of the Sigma Rox 12.0 is very good. By “very good”, I mean that timely and actionable instructions are given to get me from A to B.

The turn-cues are given well ahead of a turn and are clear to read, accompanied by a clear, audible alert. Perhaps it could be a bit louder but it’s fine. The screen draws and re-draws very quickly with very few delays (normally none) and the colours used are easy to interpret, IMHO.

The route-following experience is richly packed with many functions, including the ability to see a list of turns and the ability to add a roadblock to force a re-route.

The algorithm for re-routing after a wrong turn also seems surprisingly good. (I’m going to try to break it!!)

Strava Segments & Strava Routes on the Sigma Rox 12 Review

With a Premium STRAVA account, you will be good to go with Sigma’s awesome implementation of support for STRAVA, which is one of the best that I have seen now that it has been live for a few months.

Here are the headline STRAVA features on the Rox 12

  • Up to 100 of your favourited STRAVA LIVE segments on your Rox 12 with leaderboard and your top performances. You can disable one of these on the ROX if you have too many favourites.
  • Map and proximity views of your favourited segments – here you can hunt for your favourited segments, navigate to them and then be alerted as you get close to them.
  • Realtime pacing of your segments’ efforts, supports segments-within-segments. I’m not sure of the exact method Sigma used to pace you over the segments
  • Post-workout performance stats of each of your completed, favourite segments on the Rox 12
  • Toggle from STRAVA Segments to STRAVA routes to follow a route
  • Workout sync back to STRAVA

Sigma Rox 12 ReviewNow that STRAVA has stopped supporting sensors via the STRAVA app, many more serious STRAVA users will have to rely on their cycling computer for the full STRAVA experience. The Rox 12 does that and moves beyond the smoke-and-mirrors advertising of some of the competition that claim to have ‘STRAVA support’ when, for them, STRAVA support just means syncing of data TO STRAVA.

I need to look a bit more at exactly how the in-Segment performance pacing works, it will likely be able to be improved. For example with physiologically-based performance cues like Xert implemented with their (free) SEGMENT HUNTER, but I can’t see that being used by any bike computer vendor apart from Garmin. In any case, Xert is probably only for the more serious performance-cyclist.

Training Planning, Scheduling plus Complex, Structured Workout Creation

Sigma Rox 12 ReviewWhilst the Rox 12 does support complex structured workouts, there is no support for any kind of calendarisation of workouts and 3rd party plans. Also missing is FE-C trainer control. These are the common, major functional areas that the Rox 12 lacks. To compensate for these omissions, Sigma let you create complex workouts either directly on the device or online in the DATA CENTER. Either way, your devices’ workout library is synchronized and backed up.

Complex, multi-stage workouts can be built with repeated intervals and recovery periods based on heart rate, time, power, duration.

Whilst super-complex goals cannot be set, like a certain Training Effect, and nor can intervals be nested within intervals. However, the functionality provided will almost certainly cover the needs of the vast majority of cyclists/triathletes.

Executing a Structured Workout & indoor trainer support

Whilst doing the research and testing for this Sigma Rox 12 review I was, unfortunately, going through an extended period of indoor trainer use, so there wasn’t much data to capture on the Rox but it did present an ideal opportunity to play with the Rox 12 instead of watching a box set that I didn’t really want to watch.

Structured workouts can be started in any sports profile, indoors or out. There is a special, configurable workout screen where you can add additional metrics to suit your training. However, the main ‘workout’ data field is fixed and is a nice, clear progress bar of the current interval.

There is no FE-C support to control smart trainers, thus a smart trainer will, simplistically, just look like a power meter as far as the Rox 12 is concerned.


Like most devices, the Rox 12 doesn’t have any specific climb-focussed functionality. However, when following a route it shows the upcoming elevation profile and you can adjust the zoom level to roughly match the length of hills you are climbing. In that respect, it’s very similar to the Wahoo ELEMNTs.

There are about 20 climb- & elevation-related metrics so you should be nicely sorted there if you are interested in metrics like VAM and grade.

TIP: A general tip for those of you who want climb-related functionality. You could use to automatically create climbs as laps when you analyse your workout or when planning a route, you could use waypoints to represent the starts and ends of your routes. These will then give you both climb specific stats for in-ride and post-ride usage.

Of course, if you have chosen a STRAVA segment that just happens to represent a climb then you will get the STRAVA metrics as well.

GPS Accuracy – Sigma Rox 12 Review

A Sigma Rox 12 review wouldn’t be complete without a good look at GPS accuracy and elevation accuracy, let’s do the first of those…GPS.

If you think this image shows a glamourous ride next to the beautiful River Thames then think again. There are some nice STRAVA segments off to the West of the map but to get there requires traversing unpleasantly bumpy roads right next to the sewage treatment works. #LivingTheDream

At the zoomed-out level, you can see the Rox (Blue), iD.TRI (Red) and ELEMNT (Green) are nearly identical, although the second image shows some deviation when zoomed in but not more than 4-5m from the Rox, so all is good.

A little bit more detail with the same devices on the same ride doesn’t show anything of too much interest. Perhaps some of the trees in the first image cause a minor GPS irritation? The interesting thing for me was that this ride covered a few of the sections of my ‘standard GPS test RUN‘ and just being a metre or so further from the houses with a better view of the sky and travelling more quickly on the bike give generally MUCH better tracks. However the one point of difficulty where the Sigma Rox 12 struggled was, strangely, when going past the relatively (UK-) famous Sigma Sports bike shop in the 5th image. Maybe the Sigma Rox wanted to look at the awesome bikes in the Sigma Shop window or maybe it wanted to start a trademark infringement lawsuit..who knows?! Either way the Rox deviated a bit because there are some 2-storey buildings close to the road.

So I tried cycling close to walls and trees again, somewhere else, on a different day yet got acceptable results [Rox blue, Elemnt Red, iD.TRI Green]. The fourth image is surprisingly good as it is running East to West about 2m from a 3m high brick wall almost continuously for over 1km…Good results from all (only part of the wall section is shown).

On a longer route in Surrey, there were some mildly interesting results. Here we have Wahoo Bolt (Pink), Polar Titan (Galileo, Yellow), Garmin 945 (Glonass, Green) and the Rox (Red). When there are quite a few devices you generally do NOT want to see the device in question (Rox, Red) at all. ie if it’s obscured by all the other tracks it’s probably doing alright. The Rox DOES perform generally ‘alright’ and you can see some deviations by it on the 3nd and 4th images where trees are involved. The Polar is probably just about the worst of all 4 (Galileo…strange that) but it’s a close thing as all the 4 devices mess up at some point or other.

Elevation Accuracy

I’ve got lots of shorter, mostly flat rides like this one which doesn’t reveal too much about elevation accuracy and, because of end-of-season duathlons, I don’t have anything higher planned for a while (I’ll add some more charts in later, maybe Nov). These are pretty cool performances though.


Sigma Rox 12.0 Review – Interesting One-Off Points

These are some stand out features and interesting ‘finds’

  • Rox 12 (but not iD.TRI) supports dropbox. This is awesome and very useful for me !!
  • OSM Maps
  • Micro SD Card is mostly superfluous although can be used for additional storage of training and tracks.
  • Only Rotor is connected via ANT+ and BLE. Other BLE sensors cannot be paired.
  • Sensor support: BLE=no, ANT+= yes, speed=yes, cadence=yes, combo=yes, power=yes, varia=no, fe-c=no
  • So the BLE HRM is to support transmission to, for example, Zwift or an app.
  • WiFi upload of completed workouts and WiFi sync to online sports data services eg STRAVA
  • It is possible to connect the Rox to a WiFi hotspot on your smartphone when away from home. Not tested.
  • Has a lanyard/tether slot and tether #Recommended
  • A 5v/1A battery pack can be used for charging
  • I have had over 10 hours of battery usage without a recharge – screen brightness and navigation/renavigation will lower this level of performance
  • The screen is generally readable but polarised sunglasses impact readability
  • A 300km limit exists for calculated navigation but a pre-prepared GPX track can be much longer.
  • Hammerhead Karoo allows side-loading of Android apps, Rox does NOT allow this despite also being based on Android
  • Nice to have nutrition and hydration alerts.
  • Rox generates TBT instructions (cue sheet) by itself when loading from a route file that does not contain TBT!
  • Some good user tips at Richard Stum’s site
  • Firmware features update list: here
  • There is no manual although you might find a mostly-useless ‘user guide’ if you care to look hard enough!

Sigma Rox 12 – Navigation Alternatives

Sigma Rox 12 Review

The Hammerhead Karoo probably has the best thought-through navigation environment, they just need to implement more of it to add more FUNCTION to the beauty. The Rox 12’s screen is perhaps not as vibrant as the Mio nor as crisp as the Hammerhead, yet it holds its own in this company. The V650 and base-ELEMNTs don’t have routable onboard maps and so can’t match those aspects of navigation functionality that arise from that on the Rox. The Wahoo ROAM DOES have an onboard map that’s fairly well implemented but yet the Wahoo still lacks behind the navigation functionality of the Rox. The Brytons that I’ve used are relatively basic offerings however they have a new Rider 860 which looks interesting on the navigation front…more later on that one.

Top-end Mio’s are highly functional navigation devices and their 605HC has a vibrant screen, similarly, you already know that Garmin’s Edge 1030 and Edge 830 have lots of nav functionality and usually a higher price to go with that. Garmin’s jewel-in-the-navigation-crown is popularity routing, no-one else can quite match that (yet).

Sigma Rox 12 Review

Sigma Rox 12.0 Specs

  • Wireless protocol: ANT+ and Bluetooth SMART
  • Physical Dimensions: 1.6” x 2.5” x 0.6” (4.1 x 6.3 x 1.6 cm)
  • Display size: 1.1″ x 1.4″ (27.0 x 36.0 mm); 1.8″ diagonal (45.0 mm)
  • Weight: 1.2 oz. (33 grams)
  • Battery: Rechargeable lithium-ion
  • Battery life: Up to 16 hours
  • Memory: 8 GB (note you can add a MicroSD card for even more storage space if necessary)
  • Water rating: IPX7

Now you know…

Pricing, Discounts & Availability

Sigma seems to have rationalized their distributor network recently and the only consistent source I can find is amazon in Europe and Power Meter City in the USA (links below)

The prices shown here are for the basic bundle which includes the out-front mount and stem mount. The more expensive ‘sport’ bundle also includes a speed/cadence sensor and HR strap. There are a few colour options and the coloured part of the Rox 12 is interchangeable, which is a nice touch.

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4 thoughts on “Sigma Rox 12 Review ▷ Cycling GPS Bikenav

    1. to answer your question: i use my dinger.
      as a touchscreen device with superior navigation and free map, then Sigma ($349) would say for you to compare to the 1030 ($599), maybe even the 830 ($399). 530 ($299) is not touchscreen.
      sigma WILL discount more heavily, more often. Garmin less so.
      sigma might say that their touchscreen is more responsive and that their routing engine is more responsive. Garmin would point to the non-nav stuff eg CIQ and other functionality

  1. Rose bikes in Germany are selling it for £224 plus shipping right now. Makes it a very compelling option

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