EBIKES WATCH ELECTRIC BIKE REVIEW | The best eMTB motor you can buy

The best eMTB motor you can buy

bosch cx review ebike

The best eMTB motor you can buy

Hardly any other topic in the eMTB world is as hotly debated as the motor. But does it always come down to raw power? Or are the multitude of smaller details just as vital? We put ten of the most important motors through their paces and identified one clear winner.

Before we turn to the review, a quick reminder: All participants of our annual readers’ survey will be automatically entered into a draw for a Haibike FLYON and a YT DECOY eMTB. Find out more in this article or access the survey directly with this link. Your feedback helps us to make E-MOUNTAINBIKE even better! Thank you.

Watt’s that? An introduction to key data

We often describe eMTB motors with abstract performance specifications, but out on the trails these figures won’t necessarily reveal the true character or behaviour of the bike. Instead you should take these numbers as a rough guideline of what to expect from a motor.

The power of eMTB motors is measured in watts. The average power – also known as nominal power – may not exceed an average of 250 W over a period of 30 minutes – that’s the law! All the motors in this group test meet this standard, but can easily double or even triple their peak values.

The torque is given in newton meters and tells us how strong the motor is. With up to 120 Nm torque, TQ’s motor has by far the most grunt in our group test. The motor is powered by either an internal or external battery, where the first type is usually integrated in the downtube and the second one is attached on top of it. How long the battery will last depends on a combination of its capacity and the “consumption” of the motor. We use watt-hours (Wh) to describe the capacity of a battery. A fully charged 500 Wh battery will therefore last for 2 hours if the motor draws a constant power of 250 W during this period.

All the motors in this group test meet this standard, but easily can double or even triple their peak values.

Support levels

Every eMTB motor offers several support levels. Manufacturers use a percent scale to define the support level. If a motor like the old Bosch (2015 – 2019) provides a support of 300% in the most powerful mode, it means that it triples the power the rider puts in at the pedals. Depending on the motor, the support level can range from 50% to over 400% (or even 500% in some cases). The more support levels a motor has, the more accurately it can be adapted to a specific riding scenario. This way you can increase the range by changing into Eco mode or conquer a steep hill riding in the most powerful support level.

Most motors feature a progressive mode that adapts its assistance level to your input. Using a number of built-in sensors, it detects the effort put in at the pedals and adjusts the support level accordingly – the harder you push, the more the motor will help you. This ensures a natural and intuitive riding experience, especially on trails. Such smart support levels make the shifting between individual modes almost superfluous as the motor adapts to most terrain you will encounter.

Both the support percentages and manufacturers’ performance specifications must be taken with a pinch of salt. There aren’t any standardised testing procedures, meaning that it’s not always possible to directly compare the ratings of different motors.


The best motor can only be as good as the bike it is attached to. At the same time the motor has a significant influence on the performance of the bike, with compact units providing more freedom for the design of the rear-end and suspension. In addition, both the weight and the position of the motor are crucial to the bike’s overall handling.

Displays and remotes

We use displays and remotes to switch between support levels. There is a vast choice of solutions on the market, from minimalist designs to high-tech colour displays with a multitude of navigation- and app-features. Bosch and Shimano systems require manufacturers to use one of the brands’ in-house solutions, while brands such as TQ and Brose have opened up their systems, allowing bike manufacturers to add on their own displays and control units. Despite the diversity of the systems available, eMTBers are still faced with three major issues. First off, the remote is often hard to reach or so bulky that the dropper-remote can no longer be activated. Secondly, the display or remote are often too exposed to impacts and can easily get damaged. And last but not least, strong sunlight affects the readability of the display. In this respect Specialized (Brose) and Shimano offer the best concepts. Why? Because they give you the choice of either going down the minimalistic route and keeping your cockpit tidy, or alternatively getting the full bells and whistles, information overload package.

No Comments

Sorry, the comment form is closed at this time.

Follow us on Instagram