Bosch Active Line Plus

In the last few years, Bosch has become the top-dog in the ebike world. However, can a system that was originally designed for city and mountain bikes also be used successfully on a road bike? We tried it out!

For an overview of the test fleet head to the main article: The best E-road bike motor – The 5 most important E-road bike motors on test

The Bosch Active Line Plus, or as some in our team now call it, Mr Roadflow, comes in just behind the Shimano STEPS E8000 in terms of power. With maximum support of up to 270%, it feels best at a cadence of 75–85 rpm. Under 60 or over 100 rpm it quickly runs out of steam. The assistance limit of 25 km/h is basically imperceptible, at least on the flats and you’ll often find yourself flying along at 35 km/h without noticing the lack of motor support. Additionally, our test sample definitely makes full use of the 10 percent tolerance in the assistance limit, meaning that while power is reduced above 25 km/h, it only fully disappears above 27.5 km/h. Out of the saddle, power peaks are adapted to quickly, though the motor also compensates for the dead zone in your pedal stroke, reducing its power only slightly – that doesn’t create a very natural ride feel.

The motor responds quickly in all modes (Eco, Tour, Sport, Turbo) which we like a lot! However, we did notice a consistent small jerk when you stop pedalling. You can also hear this, but after some time getting used to it, it ceases to be disturbing. The freewheel of the motor exhibits around 5° of movement before the pedals engage the drive. In comparison, the engagement angle of a normal hub can often be between 10 and 15°, so the motor freewheel doesn’t cause any problems at all.

In terms of looks, the Bosch Active Line Plus is just as obvious and obtrusive as the Shimano STEPS E8000. However, in contrast to the Shimano motor, the Bosch produces very little noise. It’s convincing in use exactly because you can’t hear it. Even at full power, it always remain pleasantly quiet in comparison to its competitors. Bosch offers bike manufacturers five displays that can be combined with the Active Line Plus motor. In our test we focussed on two options: the Purion and Kiox display. In a direct comparison between the two, we were convinced by the colour display and operation of the Kiox. It can provide lots of well presented data, similar to that of a GPS device and changing the display page is done with a simple button press with your left thumb. The Bosch eBike Connect app allows you to connect the Kiox display to your Smartphone with Bluetooth. That lets you change settings or review your rides.

In comparison, the Purion display feels a bit dated due to its low resolution, but still shows you all your most essential data. The biggest problem is that to change the assistance mode of the motor, you have to reach away from the bars to the display to press the requisite button.

The centrally mounted position of the Bosch motor in the bottom bracket area allows frames to be constructed with a balanced weight distribution, but causes some significant problems regarding the Q-factor. The Active Line Plus makes it impossible to achieve the narrow Q-factors of a typical road bike and requires some getting used to. The system allows you to charge the battery either on and off your bike depending on what suits you best. In the end, there’s only one real question left for us to ask: where is the progressive eMTB mode from the Bosch Performance Line CX motors? The natural modulation of the CX motors would suit the Active Line Plus motors perfectly for riding out on the road!


The Bosch Active Line Plus is a declaration of German engineering prowess: quiet, powerful and unobtrusive, it provides reliable assistance in the most demanding situations. The new Kiox display convinced us thanks to its intuitive operation and clever presentation of your ride data. However, if you’re used to riding a normal road bike, you’ll first need to get used to the large Q-factor and the non-negligible system weight.

Torque 50 Nm
Motor weight 3.2 kg
Support modes 4
App control No


  • International service network
  • Smooth transition at 25 km/h
  • Operation and layout of the Kiox display


  • Heavy
  • Large Q-factor

For more info head to:

For an overview of the test fleet head to the main article: The best E-road bike motor – The 5 most important E-road bike motors on test

All motors in test: Ebikemotion X35 M1 | FAZUA Evation | Specialized SL 1.1 | Shimano STEPS E8000

This article is from GRAN FONDO issue #012

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Words: Benjamin Topf, Felix Stix Photos: Robin Schmitt