our review of Amperbike’s very first all-terrain electric fat bike

With the release of Engwe Engine X, adventurers are in for a treat. The electric bike, which is actually a “fat bike”, seems to have everything the perfect hiking companion.

Picture of the Engwe Engine X
Picture of the Engwe Engine X

According to its technical data sheet, it will be ready to withstand extreme driving conditions thanks to its huge wheels. Neither mud, nor snow, nor sand would resist him. If all this sounds very flattering, there’s nothing like a test to confound the beast. Here is our test and opinion on the Engwe Engine X electric bike.

Engwe Engine X: build and design

The American brand Amperbike has accustomed us to its robust electric bikes, built for the most part for lovers of sports activities on the bike. Aesthetically, the Engwe Engine X honors that reputation. Better still, it stands out as the very first “fat bike” designed and marketed by the American manufacturer. As such, it is characterized by its construction and design.

20 inch wheels

This bike is a mountain bike whose main characteristic is to have larger than average wheels, hence the name “fat-bike”. Indeed, the Engwe Engine X has been equipped with two huge wheels of 20 inches each, where the diameter of the wheels of a classic mountain bike varies between 16 and 18 inches. Not very fine all that, but it can be appreciated.

Engwe Engine X Electric Bike Wheels
Engwe Engine X Electric Bike Wheels

The wheels have been fitted with all-terrain tires, which are less inflated than conventional tires. If the mountain bike is, in essence, a bike designed to adapt to all racing situations and all environments, the fact that it is equipped with big wheels makes it even more versatile. It can be used as a mountain bike, city bike, forest bike, etc. A simple neighborhood stroll seduced me personally.

An alloy bicycle frame

The Engwe Engine X is an electric bike equipped with an alloy frame. You should know that the alloy is mainly made up of a metal material, generally aluminum, which is associated with other elements which make it possible to improve these properties in terms of rigidity or resistance for example.

These can be elements such as zinc, copper, chromium, iron, titanium or silicon. Typically, it makes up less than 10% of the frame, allowing aluminum to be the primary material. It must be said that aluminum is only a third of the strength of steel. Thus, the alloy itself equals steel in rigidity while retaining the exceptional properties of steel, particularly with regard to lightness.

That the frame of the Engwe Engine X is made of alloy certainly makes it heavier (and we feel it) than an exclusively aluminum frame, but it remains significantly lighter than a steel bicycle frame. The alloy is therefore the optimal compromise between lightness and robustness. I would add that the alloy frame is rust proof unlike the steel models.

Engwe Engine X frame
Engwe Engine X frame

Above all, it is much more durable and allows the bike to last for many years. It’s interesting when you know that it is a 3-step foldable frame. That it is durable allows it to hold up to the multiple folding and unfolding sessions that its use imposes on you. And it’s sure you’ll love folding and unfolding it, it’s still a lot of fun and just a bit difficult.

Other aesthetic elements

In addition to the wheels and the frame which constitute the main singularities of the Engwe Engine X, the electric bike of the Amperbike brand enjoys a remarkable aesthetic which increases its practicality.

Like any modern electric bike, it has been equipped with an LCD screen from which you have access to driving information such as speed, battery level or even the driving mode used.

It also has a front light for racing at night or in poorly lit areas. The display is great and everything is very easy to read. That said, in full sun, it’s not always easy!

Engwe Engine X LCD Screen
Engwe Engine X LCD Screen

Engwe Engine X: power and autonomy

The Engwe Engine X does not only seduce by its aesthetics. Also in terms of performance, the machine has it underfoot, with a powerful motor and an ultra-autonomous battery.

motor and battery

Installed on the down tube of the bike frame, a box protects the soul of this electric mountain bike. Indeed, the machine was equipped with a 250 W motor, powered by a removable lithium-ion battery of 48 volts, or 13 Ah, which it is possible to optimize beyond 16 Ah.

With this capacity, the battery provides a range of approximately 80 km in normal driving; with a recharge that lasts 4 hours on average. It should be noted, however, that battery life may vary depending on the assistance mode used.

Support mode

You should know that the Engwe Engine X is equipped with a 7-speed system that can be used for the two assistance modes it benefits from. With the “assisted pedaling”, it rolls at the classic speed of an electric bicycle. When you use “throttle mode”, your bike is able to go as fast as an electric motorcycle.

When using one of the two assistance modes, the range of the electric bike varies between 50 and 60 km. When you are not using either mode, i.e. without the assistance, the range of the bike is 90 to 100 km.


For this fat bike model, Amperbike has chosen front and rear mechanical disc brakes. At the front, there are stirrups connected to the fork and at the rear the stirrups are connected to the seatstays of the machine.

More durable than shoe brakes, mechanical disc brakes are less subject to wear. However, those fitted to the Engwe Engine X do not have a braking energy recovery system.

The Engwe Engine X in a few paragraphs

This fat bike mountain bike has everything you expect from a machine of its ilk: robustness, versatility and autonomy, even if we would have liked a few points to be corrected.


The alloy facilitates the assembly of the bike. In the case of an all-terrain bike, which is subjected to extreme driving conditions, knowing that you have a machine with an irreproachable assembly takes on its full meaning.

This is all the more important as the choice of alloy in the construction of a bicycle impacts its handling qualities. It is therefore the quality of the assembly as well as the mechanical properties of this electric bike that allows it to resist perfectly in rough driving.

Versatile driving

The combination of wheel size and tire quality impacts the ride in many ways. As a fat bike, the Engwe Engine X offers unparalleled ride comfort on the most hostile terrain. Since the tires are low pressure models, they provide better grip, which allows the electric bike to adapt to all roads, even the most irregular.

The whole point of investing in such an electric bike is that it is intended for all uses, whether urban driving, driving in the mountains, in the forest, on rocky or sandy terrain and even on ice or snow. It becomes superfluous to invest in a forest bike for your walks in the forest on the one hand and on the other hand in a mountain bike.

Good autonomy

That the Engwe Engine X does not have an energy recovery system does not affect the driving pleasure of the machine very much, given that it already has an impressive autonomy of 70 km, extendable to 90 km without driving mode. For an off-road e-bike, that’s a remarkable performance.

The small downside

For such a well-built bike, one would have expected a semi-hydraulic or hydraulic braking system, more powerful than mechanical disc brakes and above all, much more progressive.

Leave a Comment