A world-exclusive motor launch, the wild Atlantic coast of Galicia, and a bold message from Spain: with the M40, Mahle are entering the race with their first officially branded mid-drive motor. And it’s a strong statement. While the name might still be unfamiliar to some, Mahle have long been an integral part of the e-bike segment. Chances are you’ve already ridden one of their motors – without even realising it. This is, in fact, the third mid-drive unit Mahle developed. The first two powered the Specialized Turbo Levo SL under the Levo SL 1.1 and 1.2 badges, and were built in close partnership with the Californian bike manufacturer. But those days are over.
Mahle have been supplying drive systems for years, though until now they’ve mostly focused on hub motors for gravel, road and urban bikes. The M40 marks their solo debut in the mid-drive sector – a compact 2.5 kg motor that, at least on paper, packs a serious punch with 105 Nm of torque and 850 watts of peak power. We travelled to Vigo on the Atlantic coast for the exclusive launch of the M40, were we put it through its paces – both out on the trail and in our lab-based climbing tests.
Mahle are one of the world’s largest automotive suppliers, with their headquarters in Stuttgart. However, their e-bike division is based in Palencia, Spain – around a three-hour drive north of Madrid. That’s where roughly 150 employees, including no fewer than 115 engineers, are shaping the future of e-bike motors. So don’t be surprised if we keep referring to “the Spaniards” throughout this article 😉 If you’d like to learn more about Mahle in Palencia and their strong position in the e-gravel and e-road sectors, check out the factory visit by our sister magazine, GRAN FONDO.
The new Mahle M40 motor system in detail
Key specs: the drive unit powering the Mahle M40 system
Visually compact and sleek, the new Mahle M40 mid-drive motor is roughly the same size as the Shimano EP801 and comes close to matching the smaller dimensions of the Specialized Levo SL 1.2 motor. In terms of weight, it even undercuts the well-established Bosch Performance Line CX (2.9 kg) by a noticeable margin. Tipping the scales at just 2.5 kg, the M40 is one of the lightest motors in its class – even slightly lighter than the DJI Avinox M1, which weighs 2.52 kg. The low system weight is made possible by an ultra-light magnesium casing and an internal layout optimised for high power density.
Despite its low weight and compact size, the M40 delivers some seriously impressive figures: up to 105 Nm of torque and 850 watts peak power. But how future-proof is that level of power, especially given the looming debate around self-regulation and output limitations? That’s exactly the kind of question we tackled in our E-MOUNTAINBIKE Think Tank 2025.With the M40, Mahle are taking the initiative – whether it pays off in the long run remains to be seen. For now, there’s a lot of confusion around this issue. The current debate focuses on 750 watts of mechanically measured output at the rear wheel, not the electrical power the motor actually delivers. In other words: even if a 750-watt regulation comes into play, Mahle’s new M40 would still be within the limits.
According to Mahle, their 48V system is most efficient in high support levels – meaning when the motor is working at full tilt. It reaches its peak output at a comfortable cadence of 90 rpm, which is ideal for sporty riders and easy to maintain on the trail. Mahle also promise excellent thermal management. In fact, the M40 system is said to hold its full 850-watt output significantly longer than most of its competitors – up to 12 minutes at maximum load before it gradually enters derating mode. Even when battery levels are low, it delivers its full power – addressing a key weakness in the DJI Avinox system, which only delivers peak performance when the battery is close to fully charged.
Battery setup in the Mahle M40 motor system
With the Mahle M40, you get two battery options: the compact iM5 (534 Wh/ 2.5 kg), or the larger iM8 with 800 Wh. Both share the same casing format but differ in length. The bigger iM8 is noticeably bulkier than DJI’s 800 Wh battery, yet it’s shorter and positioned lower in the downtube to improve the bike’s centre of gravity. For those looking to go even further on long rides, the Mahle X20 Range Extender is not compatible with the new Mahle M40 because of the difference in voltage.
Charging is taken care of by the M Active Charger, which provides 4 amps – so no fast charging, unfortunately. On the upside, it comes with integrated mounts that let you fix it easily to your workshop wall. A full charge of the 800 Wh battery takes 245 minutes at an average charging rate of 3.27 Wh/min. This puts the Mahle system in third place in our big charging comparison test – quicker than Bosch and Shimano, but slower than the fast chargers from DJI and Specialized. The charge port sits above the bottom bracket and is protected from mud and moisture by a plastic cover.
Head unit and remote on the Mahle M40 motor system
System status and ride data are displayed via the Head Unit+ integrated into the top tube. It does the job, but it’s not as cleanly integrated as the displays from TQ, DJI, Specialized or Bosch’s latest Kiox 400C. In fact, it already feels a bit outdated at launch – a bit of a missed opportunity. The 1.9″ colour display has a fairly chunky bezel, which limits usable screen space. It’s operated using a small rubberised button at the bottom and only allows cycling through modes in one direction. On the plus side, the Human Machine Interface (HMI) is compatible with other Mahle drive systems, including their hub motors. That’s great news for manufacturers who benefit from a unified and constantly expanding ecosystem – though less relevant for riders.
The new Trio Wireless Remote, on the other hand, is a big step up. Sleek and clutter-free, the handlebar unit offers far better haptics than many traditional triggers (sorry SRAM!) and features three rubberised buttons to toggle modes or navigate menus. The Bluetooth connection ensures a clean cockpit without cable mess – we’re fans! The only downside? The relatively tall build means it sticks out from the handlebars more than we’d like, which could leave it vulnerable in a crash. A slimmer, more low-profile design would definitely be tougher and cleaner visually.
The Mahle My SmartBike app and ride modes on the M40 motor system
The My SmartBike app lets you connect your Mahle M40 motor system directly to your smartphone. You can tweak ride modes, record your rides, analyse stats and upload them to third-party platforms like Strava. GPS tracking and navigation are also built in, along with diagnostics and over-the-air system updates. We couldn’t pair the app with our test bike just yet – but we’re already familiar with it from Mahle’s gravel and urban bikes with hub motors.
Ride modes on the Mahle M40 system
Mahle offer a total of three assistance modes: Level 1, 2 and 3 – not exactly imaginative, but refreshingly straightforward. There’s also a Level 0 with no support at all. All three modes can be fine-tuned via the app, and the factory settings are well-balanced, ranging from natural and efficient to punchy and direct.
What sets the new Mahle M40 motor system apart from the competition?
- 1. While many motor systems – Bosch included – rely on a simple speed sensor with a single magnet to measure rear wheel speed, meaning data is only captured once per wheel revolution, Mahle take a much more precise approach. Like the ZF CentriX and DJI Avinox M1 systems, Mahle use a magnet ring with 42 slots to track rear wheel speed. But here’s the twist: Mahle double the sampling rate by using two sensors reading from the same magnet ring. This results in 84 data points per wheel revolution, which allows the system to detect changes in speed over less than 3 cm of travel. The benefits are clear: the drive unit receives faster, more accurate feedback, enabling it to regulate motor output more sensitively and respond more quickly to changes in pace or terrain. The result is smoother power delivery that feels more natural and closely aligned with the rider’s input.
- 2. Mahle also integrated an automatic Hill Brake function into the M40, which is aimed at improving safety on steep climbs. If you stall on a technical uphill and still put a bit of pressure on the pedal, the motor briefly locks up – stopping the bike from rolling backwards and letting you dismount calmly and in control. Very cool – and as it turns out, genuinely useful in practice!
- 3. Mahle stick to their principles: unlike many motor manufacturers, they follow a different brand philosophy. For them, the hero should be the bike brand – not the motor. The drive unit is there to support the brand’s unique DNA, not overshadow it. And that applies on multiple levels. Mahle don’t just want to help manufacturers fine-tune the motor’s ride characteristics to match each bike’s intended use and identity. They also want to leverage their deep data pool to help bike brands refine and evolve their own products, based on real-world usage and rider behaviour. That’s something few motor suppliers offer right now. For riders, this means two things: first, two bikes with a Mahle motor can feel completely different depending on brand, target audience and application. Second, your own riding style could directly shape the next generation of e-MTBs. Pretty exciting, right?
Comparison with rival motors:
| Feature | Mahle M40 | Bosch CX (2026 Update) | DJI Avinox M1 | Specialized 3.1 (S-Works) | Shimano EP801 |
|---|---|---|---|---|---|
| Motor weight | 2.5 kg | 2.9 kg | 2.52 kg | approx. 2.9 kg | 2.7 kg |
| Max. torque | 105 Nm | 100 Nm | 105 Nm | 120 Nm (in Boost) | 85 Nm |
| Peak output | 850 W | 750 W | 1,000 W | 720 W | 600 W |
| Support ratio | 400 % | 400 % | 800 % | dynamic (MicroTune) | 400 % |
| Battery capacity | 534 / 800 Wh | 400 / 600 / 750 / 800 Wh + Extender | 600 / 800 Wh | 600 / 840 Wh + 280 Wh | 630 / 750 Wh + Extender |
First ride: Mahle M40 e-bike motor on the trail
Looks matter too! While the motor and battery of the new Mahle M40 system can’t quite match DJI’s level of integration and visual finesse, the setup is still noticeably ahead of market leader Bosch. Our test bike had balanced proportions and a sleek, well-integrated look.
Out on the trail, the Mahle M40 impressed with powerful yet precise and well-modulated performance. The three ride modes are largely linear, offering support ratios of 100% (Level 1), 200% (Level 2) and 400% (Level 3). In other words, if you’re putting 100 watts into the pedals, the motor adds 400 watts of its own.
Glancing down at the top-tube display during the ride reveals that the M40 can deliver over 900 watts of electrical power at peak. Whether you’re pulling away or navigating technical sections, the motor never feels abrupt or too aggressive. Even at very low speeds on steep climbs, it delivers the power smoothly and predictably, giving you solid control and traction in tight switchbacks and over chunky terrain. At moderate speeds on more demanding trails, the motor remains easy to manage and provides consistent support across a wide cadence range.
You can even be in the wrong gear and the motor still picks up the slack with ease, pushing forward noticeably even at low cadences – though you do get the sense that it’s working near its limit.
What the M40 is currently missing, though, is an adaptive or dynamic support mode like those from Bosch, DJI or Specialized. These automatically adjust support based on rider input and pedalling force, reducing the need to switch modes manually.
If you want full support from the M40 on steep and technical climbs, you’ll definitely need to put in some effort of your own. The lower support ratio is noticeable compared to the DJI system, which pushes you up steep ascents with significantly more force and less rider input. Mahle offer something called Dynamic Overrun – a kind of gentle overrun that keeps you moving briefly after you stop pedalling. In practice, though, it feels quite subtle and, in situations where you need that little extra push – like climbing over a step or obstacle – it sometimes falls short. A feature like Extended Boost, which continues driving the bike forward after a deliberate pedal kick, would be a great addition to the M40.
It’s a pity: we had planned to run a direct benchmark test on our home trails against DJI, Bosch (with the MY26 software update) and Specialized, but the Mahle bike had to sit out due to a pre-production charger issue. That said, our first impression of traction and modulation was definitely positive – but we’ll only be able to deliver a definitive verdict once we’ve completed side-by-side testing. What really stood out, though, was the M40’s consistency under high loads. Despite its high output, the motor delivered stable, reliable performance throughout our testing. Even during extended periods at full load, we didn’t experience any noticeable derating – a strong testament to Mahle’s claims about efficient thermal management. The Automatic Hill Brake impressed us too: it made dismounting on steep gradients significantly safer and even saved us from one or two potential crashes. Anyone who’s ever tackled a technical climb knows the situation: you stall, need to get off, and if you don’t grab the brake quickly enough, the bike rolls backwards – best case, you do the splits; worst case, you hit the deck! With Automatic Hill Brake, that scenario becomes much less likely.
Mahle also make full use of the legally permitted tolerance at the 25 km/h cut-off limit. In other words, the motor continues to push firmly right up to the threshold, resulting in a rather abrupt power drop at the limit rather than a smooth fade-out.
In most riding scenarios, the M40 is pleasantly quiet – similar in sound to Bosch’s Performance Line CX Gen5. On our test bike, we experienced a fair amount of chain slap on descents, but the motor itself stayed discreetly in the background.
Mahle M40 – Range, vertical gain and efficiency
We put the Mahle M40 system through a controlled efficiency test using both Level 2 and Level 3 support modes under identical conditions, and also conducted a dedicated climbing test in Level 3. And the result? WOW – the Mahle M40 continues to deliver full power all the way down to 0% battery, only then dropping output to around 30–70 watts to get you home. While many motor systems start scaling back performance once the battery hits 5% or more, the M40 keeps pushing to the bitter end. That generous buffer zone speaks to excellent energy management. In real-world riding, that means no nasty surprises on your ride, even if your battery icon is blinking red.
A direct comparison between support levels 2 and 3 reveals just how much of an impact that extra power has on consumption. With a constant rider input of 200 watts, the M40 motor system in Level 3 used more than twice as much battery as it did in Level 2, while delivering an average speed that was 6 km/h faster. When rider input dropped to 150 watts, the difference became even more dramatic: Level 3 consumed three times as much energy on the exact same route. So, while Level 3 delivers a noticeably higher average speed and cuts down ride time, it does so at the expense of significantly increased consumption – without offering any real gain in elevation. If you’re aiming for efficiency with the Mahle M40, it’s best to treat Level 3 as a performance boost for punchy technical sections or short post-work rides, rather than your go-to mode for all-day tours.
| Mode & rider input | Average speed | Battery usage (percentage points) |
|---|---|---|
| Level 3, 200 W rider input | 24,27 km/h | 17 % |
| Level 2, 200 W rider input | 18,33 km/h | 8 % |
| Level 3, 150 W rider input | 20,56 km/h | 17 % |
| Level 2, 150 W rider input | 13,83 km/h | 5 % |
In our vertical range test, the Mahle M40 system, running in Level 3 with a steady rider input of 150 watts and the large 800 Wh battery, clocked an impressive 1,481 vertical metres. The ride covered 18.03 km in just over 51 minutes, at an average speed of 21.09 km/h.
| Bike | Nominal battery capacity [Wh] | Vertical gain achieved [hm] | Average speed [km/h] | Elapsed time [hh:mm:ss] | Consumption [Wh/100 hm] | Mechanical climbing energy [Wh/100 hm] | Efficiency |
|---|---|---|---|---|---|---|---|
| Mahle E-MTB | 800 | 1.481 | 21,09 | 00:51:18 | 54,02 | 17,53 | 32,45% |
With an energy consumption of 54.02 Wh per 100 vertical metres, the Mahle M40 delivers a mechanical climbing output of 17.53 Wh per 100 metres – resulting in an overall efficiency of 32.45%. That’s a solid figure for a mid-drive motor system.
The Mahle e-mountainbike with M40 drive on the trail
To mark the launch of their first in-house mid-drive motor, Mahle didn’t just present a drive unit – they developed a complete e-mountainbike from the ground up. Offered as a white-label platform for potential OEM partners, the bike allows manufacturers to integrate the M40 into their lineup quickly and with minimal fuss. And what can we say? The result not only looks great – it rides great, too!
Uphill, the riding position is sporty and slightly stretched, with enough pressure on the front to keep things stable. The geometry, paired with the powerful M40 motor, delivers excellent climbing traction and real uphill potential, especially on technical climbs. Point it downhill and the bike is composed and inspires confidence. It remains planted on the ground even on rougher terrain, impressing with plenty of stability at speed and in rock-strewn sections. In the air, the bike is easy to control, and even if you overshoot a landing, the plush suspension bails you out. The rather plush Öhlins suspension does require slightly more rider input when changing direction quickly – but overall: hats off!
An interesting spec detail: Mahle’s own bike rolls out with DH and DoubleDown tyres, an 800 Wh battery and solid components – and all of that adds up to just around 22 kg. That’s a competitive package by any measure. Speaking of bikes – the next section is all yours!
Bikes with the new Mahle M40 motor system
Five bike brands are gearing up to launch models equipped with the new Mahle M40 motor system. Here’s a first look at what’s coming your way!
ABUMS is a young eMTB brand from Spain that breaks away from the mainstream. Instead of carbon or aluminium, they build their e-mountainbikes from steel, featuring fully integrated batteries. Their approach blends high-pivot suspension design, handcrafted welded frames and responsive handling to create a bike that doesn’t follow trends – it follows a passion for gravity riding.
Labyrinth Bikes are a French brand based in the Alsatian town of Heiligenberg. Inspired by Greek mythology, Labyrinth cater to riders who aren’t just looking to pedal – but to seek out adventure, push their limits and explore new horizons. The brand stands for resilience, courage and a spirit of discovery, brought to life through innovative bikes built for gravity-focused e-enduro riding. With models like the new VTTAE powered by the MAHLE M40 system, Labyrinth are staying true to their philosophy: forging their own path, far from the beaten track.
Sants was founded in 2008 in Padua, northern Italy, and have built a reputation for building premium bikes with a distinctive design. Originally rooted in the road racing scene, the brand shifted its focus to gravel and MTB models in 2014, before fully embracing e-bikes. Today, Sants blend technical innovation, bold aesthetics and proven reliability in a range of eMTBs designed for a wide variety of riders. The integration of the new MAHLE drive system highlights their commitment to staying one step ahead – combining uncompromising performance with future-focused technology.
Conclusions about the new Mahle M40 motor system
The Mahle M40 doesn’t just shine on paper – it truly delivers on the trail. With finely tuned support despite plenty of power, clever features like the automatic Hill Brake, solid thermal management, a smart software ecosystem, and the most honest battery logic we’ve ever seen (full power right down to 0%), this system makes a strong case for itself. Sure, there’s no dynamic mode (yet) and the display feels outdated – but both are things that can be upgraded down the line. With its compact design and muscular performance, the M40 is an exciting system with loads of potential.
Tops
- Low overall weight
- Powerful yet finely controlled support
- Full performance maintained right down to the last battery percent
- Strong software infrastructure
Flops
- CNo dynamic support mode
- Top-tube display looks outdated
More info at: mahle-smartbike.com
Words: Benedikt Schmidt Photos: Mahle
