When buying a car, almost nobody asks who actually supplied the engine. After carefully weighing up the performance and consumption data, we quickly move on to other key data. With pedelecs, on the other hand, it is clear where the motor comes from: Manufacturers such as Bosch, Shimano or Brose dominate the market. Which key motor and battery data influence riding enjoyment and how is rarely explained. But it is important - and that's why it should be explained here. Before the profiles of individual common drive types, it is important to clarify key terms.
Characteristics of the e-bike motor
It describes the way in which the motor reacts to the rider's pedalling force. Is the power delivered roughly or gently when starting off, does the assistance respond immediately, at what crank speed does the motor deliver its full power? Due to different personal preferences and riding styles, there is no one perfect drive character. It is therefore interesting to compare different motors directly on a test ride.
Torque
In practice, the torque of a motor (stated in Newton metres/Nm) is the main factor determining how strongly the bike accelerates over the first few metres. It is more relevant for mountain bikes than for touring or city bikes, as it helps when overcoming obstacles, for example. The values are predominantly between 45 and 90 Nm. The particularly high-torque motors can require measured handling on loose surfaces.
Capacity of the pedelec battery
How big is the tank? The battery capacity is specified in watt hours (Wh). A common value is 500 Wh, but the trend is towards larger batteries (625 Wh). Whether the larger version always makes sense depends on the area of use, your own fitness level - and your budget. Batteries are very expensive. A bike with 625 Wh instead of 500 Wh can easily be 200 euros more expensive.
Performance
A pedelec always has the rated power of 250 watts? That's about as true as the fuel consumption figures for cars. Powerful motors can deliver 400 to 500 watts for longer periods of time. This makes you very fast on steep hills, but also drains the battery accordingly. As far as top speed is concerned, the power output is fairly irrelevant: even a powerful motor stops pushing at around 25 kilometres per hour.
Range - how far can I travel on one battery charge?
The range depends very much on the terrain, the support level and the rider's own performance. While a reasonably fit female cyclist can get 100 kilometres out of a 500 Wh battery even on undulating terrain, a heavy man can reach the end much faster in turbo mode. The MYBIKE tests provide a good comparison, as they take place under constant conditions on a test bench. With 500 watt hours, the laboratory range is typically around 70 kilometres, with 625 Wh batteries it is 85 to 90 kilometres.
That's it with the terminology. Now we continue with a comparison of different e-bike motors.
Pedelec motors in comparison
Although all the motors listed here have a rated output of 250 watts and their assistance ends at 25 kilometres per hour, they have very different characters. They react differently to how fast the rider cranks and behave the way the manufacturer has given them when starting off or going uphill. MYBIKE analyses their character on a laboratory test bench and during test rides.
Sensitive power pack: Bosch Performance Line CX
The Bosch Performance CX - just like the Shimano Steps EP8 - was originally developed as a mountain bike motor. As cyclists and car drivers alike appreciate a certain degree of over-motorisation, both are also becoming increasingly popular on touring pedelecs. With a torque of 85 Newton metres, it accelerates very powerfully. Its measured motor output reaches almost 600 watts in the highest support level, i.e. almost one horsepower. The engineers have taught it to deliver its raw power in a well-dosed manner.
Conclusion: Lots of power, sensitive response and easy to control via pedalling power.
Maximum torque: Shimano Steps EP8
At first glance, the key data of the most powerful motors from Bosch and Shimano are similar, both deliver such high torque that the gravel sprays when the pedalling is insensitive. However, the Shimano EP8 reacts very sensitively to the rider's speed: only those with an average cadence of 70 to 85 crank revolutions per minute can enjoy the maximum output of around 450 watts. And while the Bosch colleague immediately kicks in at 400 watts in the highest support level, cyclists with lower pedalling power can ride the Shimano model a little more gently. It is slightly louder than the competitor.
A bestseller: Bosch Active Line Plus
Bosch's Active Line and the somewhat less common Drive C from the German brand Brose present themselves at a medium power level and therefore very easy to ride. Both pull on the chain with around 50 Newton metres when you set off. The Bosch runs very quietly and its power is smooth and predictable when starting off. When stopping, the thrust is immediately gone. The engineers have designed it in such a way that sporty fast pedallers get little support. In the medium speed range, it delivers over 300 watts, which is sufficient for all everyday situations.
For lazybones: Brose Drive C
The Brose motor is also a pleasantly quiet drive and, despite its up to 400 watts of power, a very unagitated contemporary. This is due to its characteristics: when starting off, i.e. at minimum pedalling cadence, it is rather restrained. This feels like a natural amplification of the pedal pressure. But once you get going, it almost doesn't matter how fast you pedal or how much pedalling power you use. Even at 120 watts of power, the unit gives its all. A smooth-running all-rounder with a natural riding feel for everyday use and excursions.
Slim city bike: Bafang RM G120
The Bafang motor is located in the rear wheel hub. This design is no longer very common in the mainstream because the rear-heavy centre of gravity and (with earlier products) overheating problems spoke against it. It is also not possible to combine rear motors with hub gears. Nevertheless, small rear motors like this one have their friends. The current generation is mainly used for lighter, sportier pedelecs for the city or gravel tours. The Bafang, as a selected representative of its type, barely delivers more than the 250 watts of rated power. However, it also consumes less power than the power packs, so the battery can remain small. The main criticism: It needs a quarter turn of the paddles to start up.
Sporty approach: Fazua Evation
The Upper Bavarian company Fazua ("Fahr zu!") builds a central representative of the "Minimal Assist" drives. The idea here is to build a drive system that is so light that the handling of the bike is as close as possible to a motorless bike and the motor only helps occasionally. It is particularly popular for sporty mountain bikes and even racing bikes, as the complete drive unit including battery weighs just over four kilos, is very slim and can be almost completely removed. If you ride faster than 25 kilometres per hour, it decouples from the pedal drive and no longer brakes. It also achieves a rated output of 250 watts, but it is really fun for riders who pedal noticeably.
