Can ZF’s Bike Eco System Stir Up the Full-Power Segment?

At Eurobike, it’s always worth taking a look around to see what’s happening in the world of ebike motors. Bosch is currently focusing on digital improvements. The Pinion MGU is now fully automatic instead of semi-automatic. Shimano is expanding its portfolio with two new, more affordable products. Drone specialist DJI is launching a complete ebike to go with its new drive. And what else? Well, there is also ZF Micro Mobility and a well-launched attack on the top of the full-power units.

In recent years, the most exciting solutions have been those that have shown their strengths in areas where Bosch was either not present at all or only marginally competitive. Examples of this include TQ with the HPR50, Fazua with the Ride 60 and Mahle with the X20. It was rare for someone to challenge the top dog in a territory where it had established a near-monopoly. Very rare.

With ZF Micro Mobility, someone who has basically had to count themselves among the defeated is now going on the offensive. As early as 2020, the manufacturer launched a promising mid-motor on the market with the Sachs RS. However, it has not been able to assert itself on a larger scale since then. Too heavy. Impressive motor power with a torque of 112 Newton metres and a peak power of 700 watts – but not harmoniously dosable. That was the conclusion of many tests.

1. ZF Bike Eco System – the motor
2. ZF Bike Eco System – the batteries
3. ZF Bike Eco System – the operating and control unit
4. ZF Bike Eco System – the app
5. ZF Bike Eco System – optional components
6. ZF Bike Eco System – the outlook

1. ZF Bike Eco System – the motor

So now a new attempt is being made. With a new concept and a new name. Say hello to the ZF Bike Eco System. A complete ebike drive system including motor, control units, batteries, charger and app. Everything is based on an operating voltage of 48 volts. This is usually said to have advantages in terms of heat generation in the system and the connection of further components. In the case of ZF, other practical reasons may have played a role. The parent company, ZF Friedrichshafen AG, supplies systems for the automotive industry worldwide. There, 48 volts is the standard. In order to be able to utilise synergies within the company, the decision seems to be without alternative.

TQ as a role model?

For the Sachs RS, ZF had still chosen a design with spur gears. In contrast, the motor of the ZF Bike Eco System, which ZF has named Centrix, uses a strain wave gear. You may already be familiar with this from two motors from the competitor TQ. Its HPR50 and HPR 120S both work with this type of gear. As a point of departure for the motor of an ebike, a strain wave gear offers several properties that have a positive effect on both the subsequent riding experience and the integration into the frame. For example, the frictional connection works significantly better than with a spur gear, since an inner and outer gearwheel come into contact with each other at several points at the same time. With a conventional gearwheel, this only applies to a few teeth. A strain wave gear consists of fewer individual parts, which reduces the likelihood of defects. Above all, however, it is more compact and lighter.

At Eurobike 2024, we were able to see the small dimensions of the ZF Centrix for ourselves. The motor, which is enclosed in a cylindrical housing, fits perfectly into the frame of the ebikes on display there. It is just 88 millimetres in diameter. This means that the crank and chainring completely cover it seen from the drive side. On the opposite side, the motor cover, which is reminiscent of a swirl, sets a striking accent. At a length of 118 millimetres, the bottom bracket is quite narrow. This results in a Q-factor that matches that of a bicycle without an electric drive.

On a par with the competition

Despite its compactness, the ZF Centrix should provide plenty of power. Based on a continuous nominal power of 250 watts, it generates up to 600 watts at peak power. The maximum torque reaches 90 Newton metres. The ZF documentation does not state the minimum cadence at which you can access the maximum power. In the four riding modes Eco, Active, Sport and Boost, the motor supports you up to the usual 25 kilometres per hour. The manufacturer has not yet announced a variant for speed pedelecs. What is certain is that the ZF Centrix is suitable for use with derailleur and hub gears.

In terms of performance data, the ZF Centrix is just ahead of motors such as the Bosch Performance Line CX or the Giant Syncdrive Pro 2. It is a little behind the Brose Drive3 Peak, which has 95 Newton metres of torque. However, the motors mentioned above are all units with spur gearboxes.

Is the ZF Centrix a better TQ HPR 120S?

With a similar level of performance and also using a strain wave gear, the TQ HPR 120S is a more appropriate comparison. Its technical data, however, is in a different league. A short-term peak power of over 900 watts and a maximum torque of 120 Newton metres make even the ZF Centrix look modest. However, so much power also requires more space and weighs more. At 144 millimetres, the TQ HPR 120S measures almost twice as much in diameter and weighs around 3.8 kilograms. The newcomer from ZF weighs just 2.5 kilograms. Furthermore, the TQ HPR 120S does not set a good example from a business perspective. As far as we can tell, it is currently only being used in two e-mountain bikes from M1 Sporttechnik. Three years have passed since it was discontinued as a Flyon motor at Haibike.

However, ZF has proven that it does a few things differently from the competition. These include the integration of the motor. The ZF Centrix is attached to the frame with the help of a clamp and four screws. A burl ensures that it does not twist due to the forces that occur. From the motor a single cable runs through the down tube to a control unit called the Core Controller. This processes all the signals coming from the ZF Centrix and the sensors and controls the entire ebike system. Two cables then run from the Core Controller. One leads to an optional control unit on the left-hand side of the handlebars. The other leads to the display, which is also optional.

A duo to start with

If we have been talking about “the” motor so far, that is not correct. The manufacturer has developed two versions of the ZF Centrix. The top model is called the ZF CentriX 90. ZF considers it to be the ideal drive unit for e-mountain bikes, e-trekking bikes and SUV bikes.

ZF CentriX 90

• Torque: 90 Newton metres
• Continuous power: 250 watts
• Maximum power: 600 watts
• Weight: 2.5 kilograms

Wherever less power and a lower torque are sufficient, bicycle manufacturers could use the ZF CentriX 75 instead. Its torque is only 75 Newton metres. It can generate a maximum power of 450 watts. This could be an option for urban ebikes or e-gravel bikes.

ZF CentriX 75

• Torque: 90 Newton metres
• Continuous power: 250 watts
• Maximum power: 450 watts
• Weight: 2.5 kilograms

2. ZF Bike Eco System – the batteries

The two motors will differ in terms of their energy consumption, among other things. As things stand, bicycle manufacturers can respond to this with two different batteries. Both are solutions that can be integrated into the down tube. On the ebikes shown at Eurobike, they could be removed from below. The larger of the two lithium-ion batteries is called the ZF SI756 and provides a capacity of 756 watt hours. It weighs 4.2 kilograms, which is slightly less than the 4.3 kilograms of a Bosch PowerTube 750.

The smaller battery, the ZF SI504, weighs just one kilo less, i.e. 3.2 kilograms. However, its capacity is only 504 watt hours. Based on our impressions at Eurobike, the batteries cannot quite match the compactness of the Bosch energy storage units. One reason for this could be the different cross-section compared to the PowerTube and CompactTube from Bosch. It may also have been due to the way they were integrated into the models we were able to look at, as other bicycle manufacturers have a more space-saving approach.

According to ZF, a standardised charger is already available for both batteries. This provides a charging current of four amperes. We do not yet know how long the respective charging process will take.

3. ZF Bike Eco System – the operating and control unit

All the data from the ZF Bike Eco System converges in a central control and operating unit. The ZF Core Controller is located in the top tube and does not feature a display like TQ or Sram use with their drives. Instead, you can read the central information from twelve small LEDs that form a circle in the centre of the Core Controller. The different colours and the number of LEDs that are lit indicate the remaining battery charge and the current riding mode. Above the circle, ZF has placed the button for switching the system on and off. Below the circle, there is a button for changing the riding modes.

Above the on/off switch, you can see a magnetic pogo port. This allows you to charge devices such as smartphones, bike computers or lights directly. Of course, you need a suitable cable for this. ZF is apparently planning to offer two cables for connection to USB-C and Apple Lightning.

4. ZF Bike Eco System – the app

The core controller communicates with the ZF app via a Bluetooth interface. We can’t say much about the app yet. In addition to customising the riding modes, the app should also be able to help you navigate. It will probably also be possible to record tours and to make over-the-air updates.

5. ZF Bike Eco System – optional components

A small control unit and a display round off the operating concept of the ZF Bike Eco System. The ZF Pure Remote only has three buttons. You can use the arrow keys to change the support levels. We found the surface of the buttons to be relatively smooth. Without gloves, it feels a bit slippery in the rain or with sweaty hands. In contrast, the solution for switching the lights on and off is clever. This is done automatically by a control system linked to a light sensor. And hey presto, you’ve saved yourself a button.

In addition to the ZF Pure Remote, bicycle manufacturers can also equip their models with a colour display. The screen measures 2.8 inches. This means that the ZF Colour Display is comparable to the Bosch Kiox 500, for example. It can be operated either via the ZF Pure Remote or by touch.

Both the ZF Pure Remote and the ZF Colour Display are optional extras for the drive system. So you will encounter ebikes with different options and will probably be able to add components later.

6. ZF Bike Eco System – the outlook

Taking everything into account, ZF Micro Mobility presents a solution that does a lot of things right at first glance. Competitors such as TQ have proven that the strain wave gear does not need to shy away from comparison with other technical concepts. In terms of weight and dimensions, it even has significant advantages. The ZF Bike Eco System comes with two motors that cover almost everything that is currently being thought up in terms of ebikes. Despite the reduction to two sizes, the batteries offered should also fit well into the ideas of bicycle manufacturers. With two control units, a display and the app, the actual use of the drive seems to be on a sufficiently broad basis.

What will probably be more decisive is the extent to which the manufacturer can convince the bicycle brands to change their drive systems. Very few of them will want to give up their years of experience in integrating traditional drives such as Bosch, Yamaha or Shimano. And in times when the boom in ebike sales is demonstrably slowing down, it is likely to be difficult to expand one’s own product range as an alternative. Even if it sometimes seems that way, the market does not need an endless number of bicycle manufacturers, models and drives.

What can ZF score points with?

Perhaps the ZF Bike Eco System will win out on price. But it won’t be too low either. A look at the series launch of the system shows that. This will take place in January 2025 with the fully suspended Raymon Tarok e-mountain bike. Its equipment variants cover a range from 6,299 euros to 10,499 euros. Despite a carbon frame, a complete suspension system from RockShox and high-quality Magura MT5 brakes, the entry-level model is not a sensational announcement in the price war.

In the end, other arguments may tip the scales. ZF, for example, has proven that it is capable of successfully improving a system even after its launch. This happened in the case of the Sachs RS. In autumn 2023, it received a much-acclaimed software update. After that, it is said to have felt like a different motor. In a positive sense. Whatever happens in the next few months, we will keep an eye on it for you.

 

Pictures: ZF Micro Mobility GmbH