Avinox or Bosch? What we learned after testing their best e-MTB motors

If you are thinking about buying a new e-MTB or upgrading the one you already have, it is very likely that Bosch and Avinox will appear among your options. The Bosch Performance Line CX has established itself for years as one of the great references in electric mountain biking, while Avinox has burst onto the scene with surprising speed to position itself among the highest-rated systems at the moment.

The arrival of the new Avinox M2S and, above all, the latest update of the Bosch Performance Line CX up to 120 Nm has brought even closer a comparison that cannot be resolved by looking solely at a technical sheet.

We have tested both systems in depth, the updated Bosch Performance Line CX in the Focus SAM² 6.8 and the Avinox M2S in the Megamo Reason 2027, and although both are at a very high level, their approach to electric assistance makes a difference.

Bosch Performance Line CX vs Avinox M2S: features and specifications

The first major difference appears on paper. Avinox has taken the figures of its new M2S to a level that until recently seemed reserved for much heavier systems.

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The Avinox M2S delivers 130 Nm of torque regularly and can reach 150 Nm for a maximum of 60 seconds using Boost mode. Its peak power can reach up to 1,500 W, depending on the installed battery, and offers up to 800% assistance.

All this in a drive unit that weighs approximately 2.59 kg.

Bosch has responded differently. The latest update of the Performance Line CX allows it to reach 120 Nm of torque, 750 W of maximum power, and 600% assistance, compared to the 100 Nm, 750 W, and 400% it offered after its previous update.

It is important to note that these maximum values must be enabled by the bicycle manufacturer and that the user can configure different parameters through the eBike Flow app.

*The maximum power of the Avinox M2S depends on the battery used.

But the figures only tell part of the story. A motor with more torque or power does not necessarily mean we can climb better on a technical trail. And that is precisely what we have found after testing both.

It is also worth remembering that when choosing an e-MTB, we are not just buying a motor, but a whole system made up of battery, electronics, controls, display, app, and expansion possibilities. In this regard, Bosch has the advantage of having a very established ecosystem used by many manufacturers, while Avinox has arrived later but has done so with an integration and electronics that are precisely two of its main arguments.

Our tests: Bosch bets on control and Avinox on maximizing possibilities

The clearest conclusion after using both motors is that neither needs more power to practice mountain biking. Both have more than enough capacity to tackle practically any climb where the bike itself can maintain traction and we are able to keep control.

But they reach that point in quite different ways.

The Bosch Performance Line CX still has an extraordinarily natural delivery

If there is one thing that continues to differentiate the Bosch Performance Line CX, it is the naturalness with which it delivers assistance.

Even after raising its performance to 120 Nm and 750 W, it still conveys a very controllable feeling. When pedaling, we always have a clear connection between what we do with our legs and what the motor delivers.

This is especially important on technical climbs.

We can use high levels of assistance without the bike becoming particularly difficult to control. Bosch has managed to combine a power that is already enormous with excellent traction management, and the motor regulates the delivery very well when the terrain starts to get complicated.

In our test with the Focus SAM² 6.8, we found exactly that: we can enter a very steep climb, encounter roots or rocks, and continue to modulate the power with the pedals without constantly feeling that the motor wants to take control.

The behavior of the assistance after stopping pedaling is also noteworthy. That little additional boost, known as Extended Boost, can help a lot to overcome steps or technical points where it is impossible to complete another pedal stroke. It is not just that the motor continues to push, but that this extension of assistance is predictable enough to be able to take advantage of it without losing control.

And with its latest updates, Bosch has also considerably expanded the configuration possibilities. Through eBike Flow, we can modify parameters such as assistance, response dynamics, maximum torque, maximum power, or assistance speed within the allowed limits.

In other words, we are no longer dealing with simply a powerful and natural motor: we can now also adapt a good part of its behavior to our preferences.

The Avinox M2S has colossal power, but its great advantage may lie in everything else

With the Avinox M2S, the first impression is inevitably different.

It has an enormous amount of power.

The 130 Nm regularly, 150 Nm in Boost, and up to 1,500 W peak are well above what we need in many real mountain biking situations. If we use all that capacity, the push is spectacular.

But after testing it on normal routes, our feeling is that we do not need such a large amount of power to climb practically anywhere.

In fact, during our tests, we hardly needed to use the maximum levels except to see what it was capable of.

And here an important difference appears compared to Bosch.

The delivery of the Avinox can feel less natural when we resort to high levels of assistance. On steep ramps, we have to be especially careful about our position on the bike because the enormous push available makes it easy for the front wheel to lift.

Even using Auto mode, if a steep ramp suddenly appears and we are not correctly positioned on the bike, the push can surprise us.

This does not mean it lacks traction control. On the contrary. One of the things that has surprised us the most is how difficult it is to make the rear wheel lose grip with such power available.

The system manages traction really well.

The problem, when we seek its maximum performance, can come sooner from the front end than from the rear: we have so much force pushing us upward that we need to anticipate and position our body correctly.

Customization is one of Avinox's great strengths

But to think of the Avinox as simply more powerful would be to not really understand this system.

One of its greatest virtues lies in everything we can do with it.

The Avinox app allows us to modify numerous parameters and create configurations tailored to our liking. We can reduce that strong response and achieve a much more progressive and natural operation.

Here there is a small paradox: the M2S can offer colossal power, but we can also configure it so that it does not seem so.

The system allows creating custom modes and modifying operating parameters quite deeply. This is complemented by an interface that during our tests we found to be intuitive, both from the app and from the bike's own display.

It also offers particularly interesting functions.

One of them is the automatic shifting associated with compatible electronic transmissions, which allows for shifts even without pedaling. The system can slightly rotate the cranks while the bike is in motion to execute the shift, and once we get used to using it, it can become an important aid on the terrain.

Another striking function is the ability to link a heart rate monitor and set a target heart rate range. The system can automatically adjust the assistance to help us stay within that range.

On paper, this is particularly interesting for base training or sessions where we want to maintain a certain effort without constantly modifying the level of assistance.

It is a function that we still have pending to test in depth, so we prefer not to draw conclusions about its operation until we do so.

Avinox also has an advantage in integration and weight

There is another aspect in which Avinox has managed to set the bar very high: integration.

The M2S weighs approximately 2.59 kg and its size makes it easier for manufacturers to integrate it into frames that can visually come quite close to a conventional mountain bike.

The Bosch Performance Line CX cannot be considered heavy either, with its approximately 2.8 kg, but Avinox has managed to reduce the overall weight a bit more and, above all, offer brands many possibilities when designing the bike around the system.

In a modern e-MTB, this matters a lot. We are no longer just talking about having a powerful motor, but about the final weight of the bike, mass distribution, and the freedom each manufacturer has to define geometry and aesthetics.

Autonomy and reliability: two comparisons where caution is advisable

There are two important aspects for any buyer where we do not believe it is fair to declare a winner: autonomy and reliability.

Comparing the consumption of two motors requires doing so under very similar conditions, with comparable bikes, batteries, tires, weights, travel, and assistance levels. Furthermore, in a system like Avinox, having up to 1,500 W does not mean using them constantly. Consumption will depend greatly on how we configure and use the motor.

That is why we do not believe it makes sense to claim that one offers more autonomy than the other solely based on our tests with different bikes.

With reliability, something similar happens, although for a different reason.

Bosch has an objective advantage in accumulated experience. The Performance Line CX belongs to a family that has been evolving for years, and there is an enormous amount of bikes and kilometers traveled with Bosch systems.

Avinox is much more recent. Our experiences so far have been positive, but it is still early to have a perspective comparable to that which exists with Bosch. That does not mean the M2S is less reliable, but simply that it does not yet have the same usage history behind it.

Bosch Performance Line CX or Avinox M2S? What we have really learned from this comparison

After testing both motors, probably the most important conclusion from this comparison is also the simplest: if you are hesitating between two e-MTBs, one equipped with Bosch Performance Line CX and the other with Avinox M2S, the motor should not be the factor that decides your purchase.

There are differences between them. Bosch stands out for its particularly natural and controllable delivery, while Avinox offers more power, a slightly lower weight, and enormous configuration possibilities. As we have explained, each has its strengths.

But both work extraordinarily well and have more than enough power for practically any situation we may encounter while trail riding, enduro, or XC. We do not believe anyone will buy a bike equipped with one of these systems and later think they made a mistake because they should have chosen the other motor.

That is why, if the choice is between two bikes with these systems, we would be much more concerned about the bike than the motor.

The geometry, suspensions, the construction and quality of the frame, the weight and its distribution, the wheels, the brakes, the transmission, the rest of the assembly, or simply which of the two bikes fits better with our riding style should weigh much more in the decision.

Because after testing the Bosch Performance Line CX and the Avinox M2S, we can assure you that both are so good that the motor can stop being a concern when choosing your next e-MTB.