Launched last year, Mahle’s M40 mid-mount motor already boasted some impressive specs that few other motors on the market were able to match - 850W of power, 105N of torque, and a 600% assistance ratio.
But, there’s been no resting on their laurels, as the Spanish brand is updating the M40 motor with new features in 2026, detailed to us at Bike Connection in Italy this spring.
While we’ve not seen the motor mounted to many bikes so far, perhaps these updates, and the motor’s impressive ride feel, will tempt brands away from the more obvious options.
Updated tech will appear on bikes sold from early April, with over-the-air updates coming to existing customers coming in mid-May.
An impressive start
The Mahle M40 impressed me when I attended the launch in 2025. The motor has a uniquely natural ride feel, and yet with 850W of power, up to 600% assistance and 105Nm of torque, it’s also got plenty of punch.
Its temperature management is built to be impressive, while there’s a ton of rider friendly features, such as reducing the power when the bike is leant over in a corner.
84 points of speed sensing per wheel revolution (far more than can be achieved by motors with a wheel magnet, which only read once per revolution) give the motor far more data to work with in terms of power delivery and control.
Read my story linked above for the bulk of the down-low, along with some ride impressions.
Development never stops
Two of the existing features have been improved in 2026, while two have been added.
The Dynamic Overrun has been worked on, making the feature more adjustable than before, along with having some smart software behind it.
The overrun is set to 2m in length - stop pedalling and the motor will continue to push you forward for 2 meters. This can now be shortened, if you don’t want it to be so long.
It’s also got smarter. If the motor senses that your cadence and pedal inputs are decreasing before you stop pedalling, it will assume that you don’t want the overrun, and thus will not put power through the drivetrain when your cranks stop spinning.
If you have a constant pedalling cadence and then stop, it will continue to offer the same level of power that you were putting in, once you stop.
And, if you ramp up your inputs in terms of power and cadence and then stop, it will give you that same boost for those 2 meters - see this as an aid for getting up and over rocky steps.
When it get steep
The Auto Hold feature is one that I used a fair bit during the motor’s launch.
By pressing on the pedal when the bike is stationary but pointed uphill (its sensors know you’re on a slope), it’ll prevent the bike from rolling backwards.
Times when this function is engaged are now displayed on the unit’s screen.
When you come to start moving, the motor will now give you a little extra push off, almost like an overrun in reverse, to help you keep momentum while you get your second foot on the pedals.
The guys at Mahle told me that with a bit of practice, the Auto Hold function and its little extra get-going help can be used on super-tech climbs when you need to track-stand and hop the bike around.
What’s new?
Dynamic motor modes are commonplace on eMTB motors - think Bosch’s eMTB+ mode or Shimano’s Trail modes.
Mahle are adding a dynamic mode to their current 3 levels of assistance.
On flatter terrain the Smart Assist system will add less power, to prevent surging or excessive speeds (which of course can be added with more rider input). And, when on climbs, power delivery will ramp up accordingly.
The app and bike head unit will offer customisation for this mode, so riders looking to receive more assistance can dial it up, while those looking to put a bit more work in themselves can tune it down a little.
Keep it grippy
The final addition, Traction Control, is likely going to appeal to those of us who live in slippier climes.
As the name suggests, Traction Control is a system designed to minimise rear wheel slip on technical or loose climbs.
With the motor sensors knowing pedal inputs, motor inputs, your gear selection and the rear wheel speed (with the 84 speed sensing pulses per revolution giving more resolution than any other motor), the motor can sense when the rear wheel looses traction.
This may be through a fast acceleration of the wheel that doesn’t match the crank’s inputs, or a sudden change in the forces going through the cranks.
At this point, power to the rear wheel is reduced, with the aim of limiting the loss of traction.
It’s not entirely foolproof, and the rear wheel will still slip at times, but the length of time of loss of traction is reduced, and the aim is to prevent fishtailing up muddy climbs, or the rear wheel spitting out over wet roots and rocks.
The system has to be initialised by the rider, as it can impact on the overall ride feel, but of course it can be turned off. And, for fans of drifting on descents, the system detects you’re going downhill, and doesn’t activate itself.
These new and updated features will be available on any bike launched with the M40 as of today, while riders with the M40 bolted into their bikes will find the features appearing in their drive-unit via over-the-air updates in May.
Thanks to Bicycle Connection Agency for hosting BikeRadar during their event in February 2026.
