Review: Pinion MGU

The Pinion MGU aims to revolutionize shifting: motor and gearbox in one housing – less wear, more efficiency, and new features like autoshift. We extensively tested the unit, measured its performance, checked the range, and compared the sound with other motors. Is the MGU the future of e-MTBs?

In the standardized test at 150 watts input and 85 RPM, the MGU delivers 560 watts—on par with the Bosch CX Gen 5 following its power update and just below DJI Avinox in turbo mode.

When increasing the input to 200 watts, the output in our standardized testing procedure rises to almost 600 watts. This allows for experiencing uphill flow on trails even in the steepest sections.

Regarding cadence, the Pinion MGU is calibrated to deliver full power starting at a cadence of 85 RPM. With lower cadences, the motor output remains slightly reduced. The drop to just over 500 watts in our measurements at 60 RPM does not constitute a complete power breakdown. Rather, Pinion achieves a harmonious coupling of power to cadence. The DJI Avinox system couples its maximum output much more strongly to cadence than Pinion. Because there, maximum motor output is only achieved over 100 RPM.

The issue of efficiency loss through the gearbox actually operates in an insignificant range when paired with the motor. With an 800-Wh battery, the system climbs over 2100 meters in elevation – placing it among the strongest competition. This puts Pinion on par with established giants and exotic options like the Hepha motor, which is considered particularly efficient.

Unfortunately, we couldn’t always conduct our range test with the same battery size. However, if you adjust the values of the Bosch CX Gen 5 motors or the DJI Avinox system from the table below from a 600 to an 800 battery, those motors also achieve a comparable range.

The shifting performance is impressive for a gearbox. Normally, with gearbox transmissions on a bike, you have to ease off the pedals significantly when you want to change gears. This is not the case with the MGU. You can even shift gears under full load — not always smoothly, but extremely quickly.

Anyone who triggers a shift with the electronic lever receives the result immediately. In terms of shifting speed, the MGU is faster than any other chain drivetrains we have ever tested. Of course, you can also shift while stationary.

While the gear changes from 1-4 are smooth, the gear jump from 4 to 5 and from 8 to 9 is a bit rough. Here, the gearbox internally switches the cassette on which it operates. This switch can lead to a few degrees of ghost pedaling under full load before resistance kicks in again. Acoustically, these two “block changes” are also clearly noticeable.

With 12 gears, it delivers the industry standard. However, the 600% range is significantly larger than chain drivetrains, which in the high-end range are around 520%. As a result, some of the gear jumps are larger than you might be used to.

The automatic features are a highlight that no other manufacturer offers. You have a choice between different functions:

Firstly, you can use an app to select a gear that the transmission should engage when you’re stationary and start moving again. Pinion describes this as the Start.Select function.

With the Pre Select function, you can choose a desired cadence. When you’re rolling downhill on the trail, the gearbox always has the right gear ready to match the speed and achieve the desired cadence. All nice. But the Autoshift function is the real game-changer.

The Autoshift + function is truly a full automatic that calibrates itself and adjusts gears automatically. It sounds scary for sporty riders at first, but works surprisingly well in practice – especially on flowy trails or long climbs. Technical sections sometimes require manual intervention, which is possible at any time without turning an app on or off. The shifter remains operable even in the Autoshift + function.

Overall, the system noticeably reduces the complexity of biking with all its automatic functions. Old hands on the bike might consider some functionalities redundant. For newcomers to the sport, it helps immensely to focus on biking rather than shifting.

With a solid 4 kilos, the MGU is heavier than a Bosch CX – but: derailleur and cassette are eliminated. Factoring that out, the net additional weight is only about 270 grams. Manageable, as this means all routine maintenance is eliminated.

Plus, the weight sits low and central in the frame, which benefits handling. At the same time, the unsprung mass on the rear triangle is significantly reduced – a noticeable advantage for the suspension, which sporty riders will particularly appreciate on descents. This allows the rear suspension to work much more sensitively.

The noise level varies during the uphill depending on the gear: In lower gears 1-4, the MGU is louder, while in higher gears 9-12, it is almost inaudible. In the middle gears 5-8, the system is about on par with many full-power motors like an EP801 or a Bosch CX. Overall, the system ranges from “quieter than Bosch” to “noticeably audible”. Downhill it remains absolutely silent – no chain slap, no rattling.

Maintenance-friendliness is top-notch: An oil change every 10,000 km, plus a belt drive instead of a chain – this significantly lowers service costs and increases everyday usability.