E-MTB drives 2022: Nine current engines in a comparison test

In the past few months we have tested nine current drive systems for e-mountain bikes. In addition to detailed practical impressions, we also put each system to the test in order to substantiate (or refute) the information provided by the manufacturer and also our own impressions with comparable performance data. In addition, we looked at the available battery variants for all drives and also examined the apps, which are now de rigueur. It would be impossible to fit all the information into just one article; Accordingly, you will only find a condensed overview of the most important findings in this article. For all the details, we can only recommend the individual articles on the drives or the corresponding videos on YouTube.

As the top dog par excellence, the Bosch Performance CX has a reputation to uphold. As part of the new Smart System, it can also prove its qualities: on the test bench, it impresses with first-class top performance and at the same time very low consumption, both on the flat and on the mountain. The slightly lower power at 100 W input leaves plenty of reserves for tricky sections and at the same time offers good controllability. The Bosch Smart System has to give up a bit in terms of weight - this is not necessarily due to the motor, which at 2,9 kg is neither particularly heavy nor particularly light, but above all to the 4,4 Wh battery, which is quite heavy at 750 kg. The operating concept of the Kiox 300 display and the new LED remote is convincing, even if the latter could be a bit more compact. The Bosch Flow app, with which the smartphone can be converted into a display and which also offers numerous customization options for tinkerers, is very successful. Overall, the Bosch Smart System is a great all-rounder with no real weaknesses.

Like the competition from Bosch, the automotive experts from Brose have been represented with their own drives since the beginning of the e-bike boom a few years ago. The Brose Drive S Mag presented in 2018 can still convince with its own qualities that no other motor of the competition offers in this form: Above all, the very low noise level and the natural driving behavior are to be emphasized. The engine, which weighs 2,95 kg, does not show any weaknesses on the test bench: it has no trouble keeping up with the competition in terms of performance data – on the contrary. The consumption is a little higher than with the efficiency masters from Bosch or Shimano, but still allows very good ranges with the batteries of current e-mountain bikes. Brose has also been on the market with its own batteries and controls for some time, but many manufacturers rely on their own batteries and controls. If you own an E-MTB with the complete Brose Drive System (e.g. from Nox or M1 Sporttechnik - the entire list here), can also use the new Brose app to adapt the support parameters to their own requirements.

Bicycle giant Giant has always relied almost exclusively on its own drive system for e-bikes and e-MTBs. The latest offspring is called Giant SyncDrive Pro2 and is based on a new Yamaha PW-X3 motor. With its own software, sensors, batteries, operation and app, Giant puts its own stamp on the Yamaha unit. With a weight of 2,75 kg and compact dimensions, the motor itself is the lightest representative in this performance class alongside the Shimano EP8. In our measurements, the 85 Nm maximum torque on paper results in a maximum output of 682 W, which places the Giant drive at the lower end of the test field. The same applies to the power output at 100 W input, which speaks for progressive power development with large reserves and good controllability. When it comes to consumption, the Giant SyncDrive Pro2 performs slightly below average and uses a little more power from the battery than the competition, especially on the flat. Meanwhile, the compact controls and the extensive RideControl app are very successful.

Panasonic is probably one of the longest-serving manufacturers of e-bike and e-MTB motors - even if the drives have never been able to establish themselves in the mass market despite their convincing technology. With the Panasonic GX Ultimate Pro, the latest drive for sporty E-MTBs was presented in 2021, which is mainly installed in Flyer bikes. On the test bench, the motor, which weighs just under 3kg, surprised us with an unbelievable amount of power, which is well above what the competition from Bosch, Brose or Shimano is able to achieve. Unfortunately, this also leads to very high consumption, both on the flat and on the mountain - at least in the highest support level we tested. In practical use, the Panasonic GX Ultimate Pro is more of a stoic powerhouse than a lively dynamic. The drive is embedded in the FIT ecosystem, which not only has excellent displays and an ergonomically successful, albeit somewhat overloaded control panel, but also a very extensive app with which the support can also be customized.

It was like a bang when the cult MTB brand Rocky Mountain presented its first e-MTB in 2017, which was even equipped with a completely self-developed drive. However, the Dyname motor won over critics, fans and riders and has now been upgraded in 4.0 under the name Rocky Mountain Dyname 2021. The structure differs fundamentally from that of other mid-engines: the power is transmitted via a separate pinion and not directly on the crankshaft - another pinion measures the torque that the legs apply to the crank. This promises a particularly dynamic driving behavior, which the drive can also prove in practice. The performance data we determined already shows where the journey is going - because with a maximum output of over 750 W you even beat the Bosch CX by a hair's breadth, but with "only" 100 W input the Rocky Mountain Dyname 4.0 only provides very little support - that speaks for itself for a very progressive, dynamic handling for sporty drivers. However, this very unique characteristic can also be adjusted to your own wishes – and not via smartphone, but directly on the bike itself. Nice! What is surprising is the very low energy consumption of the motor when climbing – even if it is a little slower than the competition there.

The Sachs RS mid-engine surprised when it was presented with impressive technical data - above all, the maximum torque of 112 Nm specified by the manufacturer caused a stir. Our measurements on the test bench show that Sachs does not promise too much here: With a maximum output of almost 900 W, the powerhouse only has to admit defeat to the power leader from TQ - just like with an input power of 100 W. In this scenario we measure 753 W; Just to put this into perspective: With “only” 100 W input, the Sachs RS beats most other drives at their maximum capacity. What is unique about the Sachs RS is the "punch" that the drive has: When you start hard in a low gear, it can happen that the front wheel briefly loses contact with the ground. Of course, so much power also takes its toll in the form of energy consumption, which is well above average, as well as the volume, by the way. The dosing is also not quite optimal in the two higher support levels.

Even if Shimano only launched its own E-MTB drive quite late on the market, the Japanese have probably developed into THE drive supplier alongside Bosch by now. This is not least thanks to the Shimano EP8, which, with a weight of just 2,6 kg and extremely compact dimensions, weighs a few hundred grams less than many of the competition. When it comes to performance, the compact motor has to give up a bit and with a maximum output of 666 W it is slightly behind the competition. On the other hand, it supports very powerfully even with an input power of 100 W and is also the most energy-efficient drive in the test field. In practice, its strengths lie primarily in its dynamics and its excellent controllability. The controls with the well-protected display and the intuitive, simple and ergonomically successful control unit are also completely convincing. The support parameters can be customized in a variety of ways via the E-Tube Project app, and the E-Tube Ride app transforms the smartphone into a large display. A flaw on the Shimano EP8 that should not be neglected, however, is its volume: it is always clearly audible on climbs, even at low power, and the motor tends to rattle on descents.

The first Specialized Levo can confidently be called the “forefather” of modern eMTBs. While the Californians were far from the first to come up with an off-road e-MTB, the Levo changed the way the sport was viewed. Then as now, Specialized relies on its own drive system based on a motor from Brose. In the case of the Specialized 2.2 drive presented last year with the current Levo, this is the tried-and-tested Brose Drive S Mag. Despite heavily adapted software, its own control panels and batteries and what is probably the most comprehensive app on the market, the Brose unit can also show its unique qualities under keep the Specialized flag: Quiet, natural and yet powerful. This is also shown by our measurements on the test bench, which differ only slightly from the "normal" Brose Drive S Mag. Sporty riders are happy about a successful operating concept with a configurable color display in the top tube and a minimalist operating unit on the handlebars. The Mission Control app also offers a variety of setting options to adjust the drive to your own needs or the terrain. The Smart Control feature is also great: Here the drive regulates the support fully automatically, depending on the battery capacity, route and other factors. Be sure to try it!

The TQ HPR 120s is now more than six (!) years old - but the round engine is still probably the most powerful mid-engine on the market: With a maximum output of over 1.000W, it easily puts the competition ahead; Even with an input power of only 100 W, the HPR 120s delivers unbelievable performance data. But so much power does not only have advantages: At almost four kilograms, the engine is significantly heavier than the competition. The energy consumption is also quite high, especially on the flat. The background noise is different than with other mid-motors - the TQ is on the one hand the loudest motor in the test field, on the other hand its somewhat deeper noise is almost a little more pleasant than the loud hum of a Bosch CX or Shimano EP8. In a direct comparison with the other two particularly powerful mid-engines from Sachs and Panasonic, the TQ HPR 120s is more like the GX Ultimate Pro. It needs some time for full power development, while the Sachs RS puts all its power into the drive right from the start. Nevertheless, if you are looking for the most powerful mid-engine, you still cannot avoid the TQ.