Navimow X420E reviewed: Mountaineer with twelve blades
30.9.2026
Translation: machine translated
Pictures: Martin Jungfer
The mountain is calling! And the Navimow X420E robotic mower is coming. In our test, the device confidently masters even difficult terrain with steep slopes.
I need a different garden for this robotic lawnmower. My perfectly flat 100-square-meter lawn is no worthy challenge for the X420E. After all, a Messi doesn't play in the Challenge League. So, I'm taking the still-packaged robotic mower to the Zurich Highlands. That's where Christoph, a good friend of mine, lives. He lives in a house on a hillside: there are 50 to 70 percent gradients on his lawn, plus steep, narrow passages—a total of 130 square meters of playground for the X420E.
That's a lot of lawn, but according to the specifications, the Navimow powerhouse could handle even more:
- Areas up to 2000 square meters
- Gradients of up to 84 percent
- Multi-zone management
- Charging time of 90 minutes
- Runtime of 90 minutes
- 12 blades, 43 centimeters total cutting width
- Obstacle and object recognition with AI
- Sensors for rain and darkness
- Theft protection
The performance data, which is impressive on paper, comes at a price: around 2000 Swiss francs. In short: with its X-series robots, Segway Navimow is clearly playing in the premium class. The kind of class where it's about areas of 1500 square meters and up. Competing models include, for example, the Husqvarna Nera or the Landroid Vision L1600 from Landroid.
Installation and setup
The X420E comes with a charging station where the robotic mower has its parking spot. It's a large parking spot. The device is 85 centimeters long and 61 centimeters wide. A garage is not included. It is available as an accessory.
I'm glad there are two of us for the assembly. My aforementioned friend Christoph and I. The X420E weighs almost 30 kilograms. If I had had to heave it out of the box by myself, I could have booked an appointment with a chiropractor right away.
After assembly, we stand impressed in front of the vehicle. Christoph spontaneously renames the X420E: from now on, he calls it «Tumbler», like Batman's vehicle from the 2005 film «Batman Begins». Director Christopher Nolan described the vehicle back then as a «cross between a Lamborghini and a Hummer». That hits the nail on the head.
The robotic mower's camera module is striking: it sits elevated on the robust housing. This gives the X420E a 360-degree view. This allows it to find its way around the operating area. The Navimow mower manages without boundary wires—a technology that is outdated anyway, in my opinion. Instead, an integrated antenna and the all-around cameras help with navigation. A separate RTK antenna is included in the scope of delivery, but it proved unnecessary in the test. The robotic mower also finds its way easily under trees. Here, the camera view and the depth sensor are sufficient, or it uses correction data that it receives via mobile network through the Net-RTK module.
Capturing the work area
After unpacking and setting up, there are software tasks to be done: download the app and firmware update, set up a user account, establish a connection to the Wi-Fi. That's done in 20 minutes. Then «Tumbler» can start its first trip. Christoph controls the X420E in the app on his iPhone. It shows virtual controller fields. It goes for a lap through the garden or along the edge of the lawn. This is how the mower captures the future work area.
The robotic mower proves to be surprisingly agile. Its turning circle is remarkably small. The four wheels work independently of each other, and the two front wheels allow for an extreme steering angle. I found smaller robotic mowers, such as the Luba Mini 2 AWD from Mammotion, less agile in the test. Speaking of maneuverable: the X420E performs turning maneuvers in a very lawn-friendly way. Despite its weight, it leaves no tracks in the lawn.
After the first rough capture, the app allows for detailed adjustments. Once captured, boundary lines can be moved after tapping on them. This way, the initially generous edge area where the grass remains unmown becomes smaller. A strip of grass about 15 centimeters wide still remains along the fence, however. This is because the X420E has neither an edge-cutting disc nor an extendable mowing plate. Such features are supposed to be included in some models announced for 2027. Until then, the only thing that helps is reaching for the trimmer.
Clever behavior on the slope
Christoph's garden offers everything a tester's heart desires: narrow passages, border stones and wooden palisades as boundaries, transitions to planting areas, bushes growing over the lawn, tight angles, and extremely steep slopes. It goes wildly uphill and downhill.
But «Tumbler» proves to be powerful and clever. Instead of plunging headlong down the slope, it approaches the steepest sections from the side. The all-wheel drive with traction control, combined with the good tire tread, makes it a true climbing artist. This way, the X420E handles the slope almost as elegantly as Luis Trenker once handled the peaks.
During the test, the Segway Navimow X420E never got stuck, lost, or failed to find the charging station once. It is therefore a very reliable worker. However, it is worth mapping the terrain carefully at the beginning and identifying problematic areas so that the mower doesn't have any dropouts.
On Christoph's lawn, for example, this is a piece of lawn that is almost 100 percent steep. Here, the X420E would reach its limit and slip, which is also to be expected given the manufacturer's specification of a maximum 84 percent gradient. So, we set up a no-go zone.
Wide mowing strip and solid battery
For one mowing pass, «Tumbler» takes about 50 minutes. It mows in lanes, which saves a lot of time compared to the chaos principle of cheaper robotic mowers. The twelve blades on the two mowing plates ensure an extremely wide mowing strip: 43 centimeters. For comparison: compact robotic mowers manage at best 20 centimeters with three blades.
With a full battery, the X420E runs for about 90 minutes, after which it recharges for about the same amount of time. These are rather average values, but that hardly matters in everyday life. In any case, I don't care how long my robotic mower goes about its work during the day.
Settings and camera AI
I could look it up in the app if I wanted to know. Mainly, however, the app serves to make a multitude of settings, for example:
- The cutting height can be defined steplessly from 20 to 70 millimeters. The robotic mower has a small electric motor for this.
- The direction of the lanes can be varied, for example in a north-south direction or in a checkerboard pattern. The mower also varies this automatically if desired.
- In night mode, the X420E mows particularly quietly. However, for the protection of hedgehogs, it makes sense to let robotic mowers work only during the day.
- The robotic mower can work in different modes: standard, efficient, or precision mode. In the latter, it approaches edges more slowly and precisely and handles corners better.
The cameras play to their strengths in obstacle and terrain recognition. They identify very well what needs to be mown. By the way, the AI is so clever that it doesn't recognize a dandelion as an obstacle, but mows it down. The X420E also recognizes individual brown spots in the lawn as part of the work area. Dumber robotic mowers often stop in front of such things and drive around them widely. With Segway Navimow, I can of course still set up no-go zones in the app—in case I have just freshly seeded the brown patch.
Quality and workmanship
During the total 18-week test period, the robotic mower was exposed to heat and sun without any noticeable consequences for the material. Although the black plastic got really hot on the very sunny days, there are no cracks so far, nor has anything faded.
The blades last a long time and cut the grass for an entire season. In any case, I haven't changed them yet.
When the blade change is due, it is a simple job for the X420E and takes a maximum of 15 minutes according to the instructions. On that occasion, I could also spray down the X420E with the garden hose. Yes, I will take care of «Tumbler» a little after the summer. He has earned it.
In a nutshell
Climbing-friendly Batmobile for large gardens
The Segway Navimow X420E is a true powerhouse for large and steep gardens. Thanks to its all-wheel drive, it climbs slopes where other robotic mowers fail, maneuvers precisely through narrow passages, and never got lost during our 18-week test. The app allows for many settings, from the direction of the mowing paths to the cutting height. The only real downside: a strip of grass remains along the fence, so the trimmer is not yet obsolete. Nevertheless, the X420E is worth the money and poses serious competition to established robotic mowers from Husqvarna and others in the 2000-franc price range.
Pro
- high-quality workmanship
- mows a large area in a short time thanks to two mowing discs
- extensive setting options
- turf-friendly turning maneuvers
- very agile despite its size
- reliable navigation on the lawn
- masters steep slopes
Contra
- large and heavy device
- Edge strips about 15 centimeters wide
Martin Jungfer
Head of Content
Martin.Jungfer@digitecgalaxus.chJournalist since 1997. Stopovers in Franconia (or the Franken region), Lake Constance, Obwalden, Nidwalden and Zurich. Father since 2014. Expert in editorial organisation and motivation. Focus on sustainability, home office tools, beautiful things for the home, creative toys and sports equipment.
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