The 2020 model year starts with an engine offensive. Several manufacturers have revised their portfolios and are starting the season with new motor models. The timing is no coincidence: established manufacturers such as Bosch, Brose, Yamaha and others have been present with their drives for several years, while new providers such as Bafang and Sachs are vying for market share. At the same time, bike manufacturers and customers are increasingly demanding drive units for special or different purposes. Whereas just a few years ago a manufacturer had just one motor in its programme, today the market leaders have at least three. And because the competition never sleeps, an update is needed every few years.
Modern pedelec motors significantly improved
In fact, pedelec motors have evolved significantly over the years. They have become noticeably more efficient, smoother and quieter, and their power can now be utilised much more sensitively and intuitively.
In terms of quality, there are hardly any more differences between the well-known manufacturers, but the drives differ noticeably in terms of riding behaviour. Because legislation limits the rated power of pedelec motors to 250 watts, the differences are less to do with the maximum power output. This is significantly higher than the rated power across the board. Nevertheless, the maximum power that a drive can deliver over a longer period of time cannot be utilised indefinitely; for most motors it is between 450 and 550 watts. Rather, the motors differ in the way they react to the rider's pedalling force. Does their power kick in gently, or do they propel the pedelec forwards impetuously even with low pedalling force? How fast does the crank have to turn and how hard do you have to pedal to elicit maximum power from the drive? Very important: Doesn't the drive stop immediately when you stop pedalling?
Bosch and Brose in comparison
MYBIKE will be taking a closer look at the behaviour of the current generation of motors in the next few issues. In this issue, we start with three new motors: two models come from Bosch - Performance Line and Performance Line CX - and one from Brose. The company, like Bosch a major automotive supplier, manufactures the new Drive T Mag in Berlin, as it does all its pedelec motors. Bosch's new Performance Line was developed for everyday and trekking bikes and pulls on the chain with a maximum torque of 65 Nm (Newton metres). Compared to its predecessor, the drive has become significantly quieter. The new Performance Line CX is designed for mountain bikes with a maximum torque of 75 Nm. It has also become a little quieter and works in a new, smaller magnesium housing. A new E-MTB mode eliminates the need to change the support level. Brose's Drive T Mag for touring bikes also runs in a magnesium housing. This has made the drive 500 grams lighter and 15 per cent smaller than its predecessor. Find out how the three new motors fared in the test on the following pages.
The pedelec motors in the riding test
If you want to assess pedelec motors seriously, there is no way around riding tests. Because not everything that a drive can do can be modelled and measured on a test bench. You can only find out how sensitively a drive responds to pedal pressure during a test ride. The same applies to response and switch-off behaviour. The motor must start up smoothly and controllably and should not only start up after half a turn of the crank when starting uphill. When you stop pedalling, the motor must switch off immediately. Even a short push can provoke dangerous situations.
The test bench test
We put the motors to the test on our roller dynamometer and measured how high their maximum continuous output is. This differs significantly from the rated power of 250 watts. The test bench runs also showed that the power output differs to a greater or lesser extent depending on the pedalling frequency (cadence) of the individual motors. Measurements were taken at 20 km/h and with cadences of around 60, 70, 80 and 90 revolutions per minute. We simulated the rider's pedalling power with 100, 130, 160, 190 and 200 watts. The results can be found in the power curves on pages 24 and 25, which show not only the characteristic increase in power for each drive, but also the cadence and pedalling power at which a motor delivers its maximum support.
We also tested the influence of the support levels on the motor power. To do this, we measured the maximum power output at 70 crank revolutions per minute in each support level.
The test results
Bosch Performance Line
With this motor, Bosch offers trekking cyclists and sporty commuters a drive system that provides powerful support even at low pedalling frequencies and rides in an emphatically natural manner. The drive provides a maximum torque of 65 Newton metres and amplifies the rider's pedalling power by up to 300 percent. The most noticeable difference to its predecessor is the noise development; the drive has become very quiet and smooth-running. Its powerful power delivery is only just behind that of the Performance CX. The response and cut-off behaviour are, as is typical for Bosch, impeccable and the four support levels are well differentiated.
Bosch Performance Line CX
Currently the most powerful Bosch unit. The motor was originally developed for mountain bikes. However, because many customers value maximum power, it can also be found on other types of bike, even on step-through bikes. The Performance CX works in a magnesium housing and weighs 2.9 kilos; it is 25 per cent lighter than its predecessor and only half the size. This means that the chainstays can be shorter, which improves the handling of E-MTBs in particular. The motor delivers a maximum torque of 75 Newton metres, supported in turbo mode with up to 340 percent of the rider's power. The motor is as sensitive as usual, with impeccable response and switch-off behaviour.
Brose Drive T Mag
The Brose Drive T is available in an aluminium version and as a T Mag with a magnesium housing. This makes the motor around 500 grams lighter and 15 per cent smaller. The T version was specially developed for trekking bikes and is designed to enable a significantly greater range. The motor is extremely smooth-running and quiet. It develops its power at a significantly lower level than the top-of-the-range S Mag version. The performance is absolutely sufficient for long tours, while trekking cyclists will appreciate its very sensitive and smooth-running character. The only point of criticism: slightly too little acceleration power on hills.
You can download the complete comparative test including all test judgements and individual ratings as a PDF below the article. The test costs 1.99 euros.
Why not free of charge? Because quality journalism has a price. In return, we guarantee independence and objectivity. This applies in particular to the tests in MYBIKE. We don't pay for them, but the opposite is the case: we charge for them, hundreds of thousands of euros every year
