Sigma Rox 12.1 Evo Product ReviewSigma Rox 12.1 Evo Product Review

Sigma Rox 12.1 Evo Review


Sigma is a brand I follow closely and often recommend to friends and customers as it’s a champion of quality for the price. In Germany, Sigma bike computers are everywhere and have been the most common choice for the more experienced generation who don’t care too much about the marginal gains of additional extra specific data fields and only need a few information like speed and distance to attack the roads. 

However, for those of us who want a little more from our computers, who upload every ride to Strava, who use services like Training Peaks to track performance, and who are willing to spend the extra dollars on a good navigation system/training computer, Sigma has launched the ROX series

When I tested the Rox 11.1 Evo last year, I immediately understood Sigma’s new endgame, and the launch of the Rox 12.1 Evo sets a new benchmark for the brand. The latest Sigma technology is on par with the best training computers on the market, has already been tested in top-level competitions and is designed to make Sigma the first brand that people think of when it comes to cycling navigation. 

So in July and August I did 34 activities with the Rox 12.1 Evo, covering 2,122 kilometers and 79 hours in both Germany and Spain. How did the test go? Let’s start with opening the box:  

In the box: Computer, Mount, Sensos and Komoot Coupon

The Rox 12.1 Evo is offered in 2 different bundles:   

  • The Basic Set, which includes the computer, the basic mount and the long Butler mount (front mount);
  • The Sensor Set, which includes everything above plus speed sensor, cadence sensor and heart rate sensor.

My recommendation is definitely for the Sensor Set. It’s easier and quicker to get all the sensors at once, which will be put to good use thanks to the computer’s many functions. Cycling with cadence and heart rate sensors is a real game changer for getting to know yourself on the bike, especially if you struggle with things like pacing and knee pain. The speed sensor is a great fallback when the GPS cannot accurately track your movement, such as in tunnels, in closed woods, or when you are slowly mountain biking uphill.

The computer and accessories are very well made. The computer has been completely redesigned and looks like a real modern cycling computer. The touchscreen is very responsive and can be easily unlocked, for example, on a rainy day or when sweat starts to drip on it during a long climb. In my experience, the Sigma Rox 12.1 Evo is the most comfortable computer to scroll through, change settings, select features, change navigation destinations, etc., especially while riding. 

On my road bike I used the front butler that came with the package and for my MTB I got the Overclamp butler. Available in black and white, the Sigma Rox 12.1 Evo comes with a USB-C charging port.

Screens und Datenfelder – Very easy and intuitive to Set-Up

The Rox 12.1 Evo has a big 3” screen with a very nice 240x400px resolution. You can set up to 10 fields in one page. I found the size perfect for fitting 4 data fields on the navigation page, so I could cycle mostly seeing: Map, Power, Speed, Cadence and Heart Rate.

In addition to being customizable, the different screens can also be colorized, just like the other Rox series computers. That’s a very nice feature. I chose colors for power, cadence and heart rate, which made it much easier to quickly identify these fields during moments of higher effort. You can also choose different layouts to fit different sizes for your favorite fields. Personalizing your data fields on your smartphone using the Sigma Ride app is very easy.  

The map looks very good and allows zooming in and out. You can also create extra screens with elevation profiles and other graphics. You can move through them by swiping left and right or with the buttons on the side. 

Again, the “on-ride flexibility” is an advantage: You can switch fields while riding by long pressing on a specific field. It’s a feature I didn’t think I’d use, but I’ve done it a few times and have to say it’s handy. In fact, I’m already testing another computer and I’m so annoyed that I can’t customize the display while riding. And here I can already note the biggest advantage this computer has over the competition, and by competition I mean the top and most expensive on the market: 

Sigma has managed to create a very intuitive and easy to use software. From the moment you start the ride to the moment you finish the ride, the Sigma Rox 12.1 Evo is the computer you will struggle the least to accomplish what you want. Whether it’s creating a route or changing a few settings, you’ll get things done quickly and easily. In an age where we’re used to smartphones that can almost read our minds, this is the kind of product we want. 

Compatibility, Connections and Switching Bikes

The sensors can be connected via Bluetooth or ANT+. So you can use Sigma sensors with other brands of devices and vice versa. For example, I use the Sigma heart rate sensor connected to my cell phone for running. I also sometimes use a heart rate sensor from another popular brand with the Sigma computer when I ride my bike at work. 

From my setup during the test period, it is simply to see how easy it is to use the Sigma system: 


  • Sigma Speed Sensor on the front Wheel  
  • Favero Assioma Duo Pedals for Power and Cadence
  • SRAM Rival eTap AXS Group


  • Another brand’s Speed Sensor on the front Wheel 
  • Sigma Cadence Sensor on the crank arm 

So how does the computer deal with all these sensors? Similar to how a cell phone deals with its many Bluetooth devices: It searches for the stored devices and automatically connects to anything within range that is “awake”. That means switching between bikes is as quick as switching which phone controls the sound speakers at a party. 

For speed and cadence, awake means when the bike has moved. For example, if you keep your bikes together in the garage and need to move them when you take a bike out, you may need to walk a few feet away from the house to make sure the correct sensor is connected. 

The connection with my Assioma Powermeters and with my eTap AXS shifters was flawless. Just like with the other sensors, a warning is shown when the battery is low. I also tested the Computer with the Varia Radar for a couple weeks. After connecting with the Radar a stripe will be displayed right on the screen to show approaching vehicles.  

A Tip for Powermeter users: The average power calculation does not include moments of 0 power by default, but this can be easily changed in the settings under “Settings>Sport Profile>Road Bike (or MTB, etc)>Avg. Calculation>Average Power.

Das ist ein weiterer Bereich, in dem sich die Benutzerfreundlichkeit des Sigmas während der Fahrt bemerkbar macht. Wenn du zum Beispiel Probleme mit den Sensoren feststellst, kannst du im Schnellmenü auf die Schaltfläche “Sensoren synchronisieren” klicken, damit der Computer die Sensorverbindung zurücksetzt – auch wenn du gerade in Bewegung bist. Ich habe dieses Feature einmal genutzt, nachdem ich bemerkt hatte, dass die Verbindung zu meinem Herzfrequenzsensor abgebrochen war. Ein Klick und ein einziger Bildschirmwechsel und nach ein paar Sekunden war alles wieder da.


With the launch of the Rox series, Sigma has opened a new chapter in its relationship with navigation, which is not really the first feature that comes to mind when you think of Sigma computers. The Sigma Rox 12.1 Evo, however, should definitely change this opinion. Not only has Sigma managed to match the navigation features found on top models from leading brands such as Garmin and Wahoo, but it has surpassed them with not only exclusive features such as multiple “back to start” options, but also with the best re-routing calculation I have ever used.  Before talking about turn by turn navigation however, it is necessary to define what navigation is: 

When driving a car, navigation means defining the shortest or fastest way to reach a destination. While this is sometimes exactly what we want to do on a bike, what we usually want to do is define a path with the same start and end point that passes through certain locations along the way. These locations could be a forest, a local climbing spot, a friend’s address, etc. 

That’s why bike computers usually have a problem recalculating the route when you leave the path: They usually cannot tell which parts of the route are important to you and which can be skipped, resulting in a lot of unnecessary, unproductive, and annoying rerouting or “Make a U-TURN” messages.  Not with the Rox 12.1 Evo.  

In this regard, the Sigma Rox 12.1 Evo’s software is the best I’ve ever used to quickly realize that I don’t want to make a “U-turn” and recalculate the fastest way to get back on track. With other computers, even the leading ones, intentionally going off track forces you to ignore the computer for the next few miles, erase a lot of “U-turn” messages, and navigate by yourself using the map and your knowledge of the area. In contrast, you can still trust the Rox 12.1 Evo if you change your mind a few times during the ride or if you encounter blocked roads. 

Loading Routes, Komoot and Strava

As in other Sigma Rox versions, the easiest way to manage your tracks is to use Komoot. Especially in Germany Komoot is a widely used platform. If you’re going on a group ride, the route will most likely be shared via a Komoot link. After saving the route in the Komoot app on your phone, the Sigma Ride app will load it into your tracks. It works the same way with your saved Strava routes. Alternatively, you can download a .gpx file from a Strava or Garmin Connect route or activity and load it directly into the Sigma Ride app using the “+” button. Click the star to save it as a favorite and the route will be sent to your computer the next time you sync. 

Many features ready, many more to come

In addition to popular features such as Crash Detection, E-Bike Support, Radar Support, Back to Start, Eat and Drink Alert, etc., there are many exclusive features such as Draw my Route, which allows you to draw routes with your finger directly on the computer and it will calculate an approximate route based on your drawings.

In fact, the Sigma Rox 12.1 Evo is very good when you need to navigate somewhere using the computer directly. You can enter the destination, navigate back to the start, write addresses, select POIs, draw routes with your finger, and so on, and the computer will do the rest.

And because Sigma is constantly updating the Rox Evo 12.1 system, there are many more features to come. 

My conclusion: Mega price/performance ration with the bonus of being made in Germany

If you are looking for a full-featured computer focused on navigation, the Rox 12.1 Evo is the best bang for your buck. It has all the important features for most cyclists combined with the easiest to use and in my opinion by far the most eficient navigation on the market.

While on vacation in Mallorca, I downloaded several Komoot routes created by strangers and the Sigma navigated me perfectly around the island and back home, often recalculating the route on the fly. No more reaching for your phone to check the navigation with the Sigma Rox 12.1 Evo.

Sigma is also testing the computer extensively with professional athletes, including Germany’s first ever gravel champion, Lukas Baum, who rode to victory in Daun with a Sigma Rox 12.1 Evo on his handlebars. This means that we can expect even more from the Rox 12.1 Evo in the future.