Test / Drives: With the ZF Centrix we were able to test one of the most exciting new e-bike drives for the 2025 model year in practice on the e-mountain bike. The small powerhouse performs impressively.
There's no question that the ZF Centrix was one of the biggest highlights at this year's Eurobike. No wonder, after all, the drive promises something that previously seemed impossible: full power with compact dimensions and low weight.
Almost unbelievably small
In numbers, this means that the ZF Centrix is designed to deliver up to 90 Nm at 600 watts of maximum power, but only weighs 2,5 kg and, above all, is extremely compact. This is made possible by the internal structure, which is fundamentally different from that of most other mid-engines on the market. ZF uses a wave gear instead of the otherwise usual planetary gear, and the other components have also been optimized to save as much space as possible.
Of course, ZF was able to draw on an incredible wealth of experience in the field of transmissions and engines. This is said to have made it possible to effectively dissipate the heat that is generated in such an engine to the outside - despite the extremely compact dimensions. To achieve this, a special transmission oil is used, which not only serves as lubrication but also as a heat conducting material and dissipates the heat evenly to the outside. This is also where the innovative fastening in the frame comes into play: the engine is not screwed directly in, but is clamped into the frame from below using a clamp. This aluminum clamp not only serves as fastening and protection, but also provides an additional cooling surface.
Another fundamental building block for size and performance is ZF's decision in favor of a 48V system, while most other e-bike drives still use a 36V infrastructure. The lower currents not only increase efficiency, but also reduce heat losses.
batteries, displays and peripherals
With the ZF Centrix, the traditional German company is also introducing a complete e-bike ecosystem. In addition to the motor itself, this of course also includes batteries, control units and displays. The batteries will initially be available with 756 Wh and 504 Wh. Unfortunately, both are quite heavy at 4,2 kg and 3,2 kg. This could also be due to the solid metal housings, in which the mounting points are also integrated in the frame. There is a special rail for this that is screwed into the frame and onto which the batteries are pushed. This eliminates the fiddly and error-prone adjustment of the battery lock and frame tolerances no longer play a role. In addition, both batteries are easily interchangeable and fit on the same rail.
The corresponding lock and a connection terminal are also integrated into this battery rail: the motor itself only has two connections, one of which is used for the power supply, the other connects the speed sensor on the rear wheel to the system. All other ports for operation or lighting are located on the power terminal.
The brain of the system is located in the top tube and is called the core controller. This is connected to the terminal with a cable and is the only component required to start the system. The e-bike can be switched on and the support level changed using two buttons. LEDs provide information about the mode selected and the battery charge level. A special cable can be attached to a magnetic connection on the top, which can be used to charge the smartphone with up to 20 W. The specialist dealer can also use this connection for diagnosis or to update the system. Speaking of updates: The system is basically prepared for updates via the smartphone, but it is currently questionable whether the functionality will be available when the first bikes are launched.
Optionally, additional components can be connected to the Core Controller. At market launch, there will be a compact control unit for the handlebars with three buttons and a large, color display with touch function.
The ZF Centrix in Practice
We tested the ZF Centrix in the new Raymon Tarok. The bike has 160 mm of suspension travel at the front and rear and rolls on mullet wheels. The test site was the Weingarten bike park near Ravensburg, which offered good conditions for testing with a wide variety of terrain.
During the two-hour test ride, we were able to put the new drive to the test. The first thing that stands out is the surprisingly powerful support and the sometimes almost unbridled acceleration. The Centrix has enormous punch, especially in the lighter gears, and is clearly ahead of Bosch, Shimano and Co. In steep terrain, it is also quite unimpressed by the cadence: it handles even heavy gears well and stoically pulls the rider and bike towards the summit.
For most of the time we were either on the highest support level, Boost, or the progressive support mode, Sport. There are two other, slightly tamer modes below that. Using a smartphone app, it will be possible to adjust the characteristics of the individual levels yourself. However, we were not yet told whether this will be available when sales start.
The controllability of the drive is also pleasing, even if a little fine-tuning may still be necessary before the launch in a few months. While the power of the drive can be applied very sensitively to the ground with a lot of chain tension and heavy gears, this is sometimes a little more difficult with light gears and the drive almost has a little too much acceleration when starting. However, ZF is still working on the tuning in some areas and it is quite possible that this will also need to be fine-tuned before the launch.
The volume of the ZF Centrix on the downhill trail is absolutely positive: The Raymon Tarok was whisper quiet and at no point was there any unpleasant rattling or similar from the drive - great! That's exactly how it should be. Uphill, the motor is not always completely quiet: While the support noise disappears under the rolling noise of the tires at moderate power, things are a little different at full power. Here, the drive is clearly audible, but the volume is still within a reasonable range. Because the tonality is a little lower, most drivers will find it less intrusive.
For your own impressions of the volume and detailed practical tests, we recommend our test video:
Overall, the ZF Centrix is an impressive engine. So much power in such a compact design was previously unthinkable. The fact that the response, features and controllability are also at a high level in most scenarios, the engine doesn't rattle and the peripherals make a good impression - great! At this point in time, we wouldn't see it as too tragic that there is still some room for improvement in terms of controllability in a few scenarios.
Web