Judging by the name of the new Sigma Rox 12.1 EVO, you wouldn’t think a huge amount had changed from the previous 12.0 model, but open the box and you’ll find it’s a different story – the 12.1 EVO might as well be a whole new model. In addition to the updated design, its internal hardware has been greatly improved. It offers route planning, training functions and much more. But can it really keep up with the big players in the head unit business?

SIGMA ROX 12.1 EVO I Tester Martin | Distance 512 km | Price € 379.95
Weight 112 g | Usage navigation, training, route-tracking
Manufacturer’s website

Sigma used to be a household name in bike computers, dominating the road odometer market. In 2014, Sigma reported 50 million devices sold, but then the brand seemed to miss the boat when GPS devices began to hit the market.

Today, the German company are back with four GPS bike computers. The flagship model, the Rox 12.1 EVO, offers comprehensive navigation and training functions, as well as compatibility with gadgets such as heart rate monitors and Garmin Varia rear lights. Can Sigma regain a foothold in the bike computer market with this comprehensive package? We’ll tell you which features of the new GPS computer are really useful, and which are not.

Facts and figures of the Sigma Rox 12.1 EVO

  • Dimensions (L x W x H): approx. 95 x 57 x 21 mm
  • Weight 112 g
  • Display size: 3″ diagonal with colour display (16 million colours by our count) at 240 x 400 pixel resolution
  • Waterproof and dustproof to IP67 (i.e. temporary submersion to a maximum depth of 1 metre for a maximum of 30 minutes)
  • Connectivity BLE, ANT+, WiFi, USB-C (should have something for everyone).
  • 8 GB internal memory
  • 2 colours to choose from, white and grey
  • The Sigma Rox 12.1 EVO Basic Set comes with two mounts, handlebar tether and cable for € 379.95

Packed full of features – What can the Sigma Rox 12.1 EVO do?

The Sigma Rox 12.1 EVO bike computer has three key functions:

  • Navigation
  • Data recording
  • Training functions

It also offers handy features such as drink and eat alerts, low battery warnings for paired devices, smart notifications when connected to your smartphone, plus different profiles for various bikes.

Which way? Navigation with the Sigma Rox 12.1 EVO bike computer

The core feature of the Sigma Rox 12.1 EVO is its versatile route planner. Routes can be imported from external providers or created directly on the device. There are several options and settings for creating routes on the Rox. You can enter an address, draw the route on the display, or find your way back home at the touch of a button. Various settings allow you to adjust the route more precisely, and the Rox offers three different route suggestions to choose from. The pre-installed maps cover the whole of Europe, highlighting cycle paths and trails.

Am I in the right place? Unfortunately, the Sigma Rox 12.1 EVO will have you asking yourself this question a lot. The navigation takes some getting used to.

Track Attack – Data recording and analysis on the Sigma Rox 12.1 EVO bike computer

The Sigma Rox 12.1 EVO bike computer is capable of collecting and displaying a variety of data on up to six customisable pages. Up to ten data fields can be individually configured per page, allowing you to tailor the display to suit your specific needs. Pre-configured templates allow you to easily customise the layout of each page. This flexibility allows certain data fields to be enlarged or placed most conveniently for quick glances. In addition, each fieldfield can be highlighted in a different colour for improved visibility, ensuring that critical information stands out during your ride.

The Sigma Rox 12.1 EVO covers all the usual metrics such as distance, altitude and more. However, there is a notable lack of climbing-related functions that you might find on other devices, which is a major drawback for those who enjoy tackling hills and mountains. After the ride, your data can be analysed both on the device itself and in the Sigma Ride app, available for iOS and Android. In general, the app is clear and easy to use, although some functions and settings are somewhat hidden.

More colour! The option to assign a different colour to each data field makes the display visually clean and user-friendly.

Watts more – The training features of the Sigma Rox 12.1 EVO bike computer

In addition to measuring wattage, the Sigma Rox 12.1 EVO bike computer offers a comprehensive range of training data, including TSS (Training Stress Score), IF (Intensity Factor) and pedalling balance, which tracks the pressure ratio between the pedals. After each session it displays personal records such as longest ride, maximum speed and FTP. The device comes with six pre-installed workouts, including VO2 Max and SST, with the option to add more via .fit files from Sigma or third parties. These workouts are designed around speed, heart rate, power and cadence data, with specific target zones to optimise your training.

As you train with the Rox, the target zones are clearly displayed, while the customised and colour-coded data fields ensure that you always have a good overview of your performance.

Touchscreen and buttons – Operation, connectivity and ports on the Sigma Rox 12.1 EVO bike computer

The Sigma Rox 12.1 EVO bike computer has five buttons: three on the right and two on the left side. These buttons allow you to change pages, switch the computer on and off, start and stop your ride, zoom in on the map and start a new lap. All other settings are made via the touchscreen. The Rox 12.1 EVO is also compatible with ebikes, displaying information such as battery status. You can also pair it with a smart trainer to use it as a training tool. The USB-C power port is located on the underside of the computer. The connection to services like Strava, Komoot and Training Peaks is very good. Connectivity is quick and easy to set up through the Sigma Ride app, and data exchange runs smoothly.

Three on the right…
…Two on the left. The Sigma Rox 12.1 EVO has a total of five buttons.

How did the Sigma Rox 12.1 EVO perform in our test?

Switching the Sigma Rox 12.1 EVO bike computer on and off takes a relatively long time – about 45 seconds from pressing the button until it is ready to use. However, once it’s on, the GPS signal is immediately available. The menu is clear and easy to use, reminiscent of a smartphone, although the response time is not as fast as on newer devices from Garmin and Wahoo, possibly due to the software.

Touchscreen control is generally simple and intuitive, but the touchscreen seems a little dated for 2024. The layout is good and not too cluttered, although operating via the five buttons takes some getting used to. The display is quite sensitive to moisture, and reacts to the first raindrops. This can be remedied by locking the screen, but that has its obvious drawbacks. There is a lack of contrast in sunlight, especially when the brightness of the screen is low.

The power connector on the underside works well with an aero mount, or when attached to the handlebar. However, it is not suitable for mounting on the stem or with some stylish integrated computer mounts.

Switching between screens while riding is easy, by using either the buttons or swiping across the screen. However, zooming in and out of the map is a bit more difficult, requiring an extra operating step. The Sigma Rox 12.1 EVO’s battery life varies according to use. Sigma claim a maximum of 22 hours, but this is without using the backlight or navigation. With full brightness, navigation and paired devices, the battery life drops to around 10 hours. In everyday use, we found the battery lasted between 12 and 14 hours.

Unfortunately, the Sigma Rox 12.1 EVO offers little contrast in bright sunlight, even when set to full brightness.

Navigation and planning with the Sigma Rox 12.1 EVO generally works well. Creating routes on the unit is simple and intuitive, and they can be easily customised. Once planned, three different route options are available to choose from. The navigation while riding works well, although the turn-by-turn instructions could be improved. Sometimes turning instructions are missing where they would be helpful, while at other times unnecessary ones appear. At the end of a recording, the data is processed quickly and can easily be transferred to the app, or to other services such as Strava. Particularly cool are the device’s achievement awards.

Could be better. The touchscreen is not quite state-of-the-art and, unfortunately, a little slow.

Conclusion on the Sigma Rox 12.1 EVO

The Sigma Rox 12.1 EVO is a very useful device for navigation, training and data recording. Its route planning feature is particularly worth highlighting. However, users may need some time to get used to the occasionally arbitrary turn-by-turn instructions, as well as the way the route is displayed during navigation. Priced at just under € 380, the Rox 12.1 EVO offers a comprehensive set of features that will appeal to riders looking for robust performance without having to go for the top-of-the-range models from the competition. For everyday use, the Rox 12.1 EVO efficiently handles all of the essential functions, making it a reliable companion.


  • easy route planning on the device
  • wide range of indoor/outdoor training features
  • different coloured backgrounds for data fields


  • inconsistent turn-by-turn directions
  • slow touchscreen
  • contrast and brightness

For more information, visit sigmasport.com

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Words: Martin Staffa Photos: Martina Staffa, Jens Stöbe