E-MTB motor comparison: Find the best e-drive for you

Which mid-engine from Bosch, Shimano or Yamaha should it be? The motor is the heart of E-MTBs and a huge buying criterion for e-mountain bikes. We compare the most important E-MTB motors, go into details about the electric motors and help you find the right drive for your E-MTB.

An E-MTB consists of more than 100 components, but most people only talk about one: the E-MTB motor. So it makes sense to ask yourself a few basic questions before buying an e-mountain bike: How powerful should the drive be? Does Bosch, Shimano or another manufacturers build the best E-MTB motor for your needs? Which engine position is right for you? Clear legal requirements apply to the electric drive, that turns the bicycle into an E-MTB (strictly speaking, a “pedelec”, because the motor only supports you when you pedal): The maximum permissible rated continuous output is 250 watts and the E-MTB motor may only provide support up to a maximum speed of 25 km/h. These two points apply to all E-MTB motors, which we will examine in more detail in our purchase advice. Why? Because only these e-drives make sense in sporty E-mountain bikes and you need neither a driver’s license nor insurance to be allowed to ride them. We answer all these questions and take a look at the most exciting engines of the 2023 season.

E-MTB motor position: Where is the motor installed on the bike?

Is the electric motor in the middle or at the back? These two variants of motor positions have prevailed in sporty E-MTBs. On the vast majority of E-mountain bikes, the e-drive is mounted centrally around the bottom bracket, which is why it is called a mid-motor. If, on the other hand, the motor is located at the back of the bicycle in the rear wheel hub, this is referred to as an E-MTB with a rear motor. Both systems have design-related advantages and disadvantages:

1. E-MTB mid-motor: Guarantees the best riding experience

Since E-MTB motors weigh around 2.5-4.2 kilos, the central motor guarantees optimal weight distribution (very central) and ensures that the bike has a < strong>low center of gravity. This benefits the handling of the bike. The drive in the bottom bracket area can be sensitively controlled via the cranks and it transmits its power directly into the bike’s drive train. Another advantage of mid-motors: Motor unit and battery are close together, which simplifies connection and wiring. The only disadvantage of E-MTB mid-motors: The drive train is exposed to higher loads, which wears the chain and cassette. Due to its design-related advantages, sporty E-mountain bikes are almost exclusively built with mid-motors. Another indication of the triumph of the mid-motor: The largest motor manufacturers such as Bosch or Shimano produce their E-MTB drives exclusively as mid-mounted motors.

2. E-MTB rear motor: push from behind

The rear wheel motor is often found in 45 km/h fast S-Pedelecs and sporty E-racing bikes and E-gravel bikes. This is where the rear motor shows its advantages: It is usually very quiet, does not wear out the chain, cassette and shifting components in the same way as a mid-drive motor and, on top of that, you can also use derailleur with a rear-wheel motor that can ride with multiple chainrings. For sporty E-MTBs, however, one disadvantage weighs too heavily: The weight of the motor is very rear-heavy and the center of gravity of the bike moves backwards. This is why rear motors are only found on very cheap E-mountain bike hardtails for beginners or E-road bikes. The rear wheel motors then usually come from manufacturers such as Bafang, Mahle or Neodrives.

E-MTB motors have more power than the official continuous output

You read them, you know them, you compare them: The official continuous output power of E-MTB motors is omnipresent when buying an E-MTB. But be wary, because the value given for most motors with 250 watts has little to do with reality. The Bosch Performnce CX motor or Shimano’s EP, for example, are given 250 watts of continuous nominal power. In reality, however, they deliver power peaks of well over 500 watts. If you pedal with a sporty 250 watts and the motor shoots in an additional 500 watts on the climb, you can climb even the steepest climbs in no time, thanks to a total output of 750 watts.

What does the official continuous power of E-MTB motors mean then?

The manufacturer’s specification of the rated continuous power is more or less a formal value so that manufacturers can easily achieve approval according to the European test standard. The main thing is to complete a 30-minute test without the engine overheating. The exact test regulations are not very specific and leave the manufacturers a lot of leeway in the design. It almost seems like a gentleman’s agreement that most major manufacturers have agreed on this value. Our conclusion on the subject: The value specified by the manufacturer is misleading. This value is fundamentally revised to really establish a practical reference. Currently, the rated continuous power output should not influence the purchase decision excessively.

The power development of E-MTB motors is much more meaningful than the official power output

A meaningful indication of the performance of a motor would be the multiplication of human pedaling power. Some manufacturers such as Bosch state that their motor provides support with a maximum of 340%. That means: If you pedal with 100 watts, the motor will also help with a maximum of 340 watts. This information actually allows for a much better conclusion about the riding behaviour of an engine than the specified power output.

Heads-up: Power is not the same as torque with an E-MTB motor

In addition to the power output, the maximum torque of a motor is always specified. The two values are only related to a limited extent (via the speed). However, the maximum torque allows very good conclusions to be drawn about the motor or rather the support characteristics of the E-mountain bike. The torque stands for the power of the rotary movement of the motor. A high torque ensures that motors are very powerfully supported even at low speeds, e.g. when starting off. This often conveys a sporty character of the E-mountain bike. But more torque is not necessarily better. The character must fit your preferences. In principle, the torque specification for E-MTBs can be compared with that of cars: the higher the engine torque, the sportier the car can be accelerated. This value has a significant impact on riding behaviour, especially when starting off and shifting through the gears. It loses its importance when cruising along in a relaxed, even manner.

E-MTB motors: What really matters

The classic E-MTB mid-motors have a rated continuous output of 250 watts, have 3-5 different levels of support that can be selected and accelerate the E-MTB up to a maximum speed of 25 km/h. But also besides the bare engine numbers, there are some differences between the manufacturers and models that you should consider when looking for the right E-MTB engine:

• Weight: Good E-MTB motors weigh between 2.9 and 3.5 kilos, so there are not big weight differences. As a percentage of the weight of the complete bike, this weight difference still accounts for almost 5%. The factor is therefore not negligible.
• Support levels: For E-MTB motors, the support is always given as a percentage. Most manufacturers state the maximum drive support of their motors. This means the support as a percentage of your own contribution. 340% in the Bosch turbo mode means that the E-MTB motor brings 3.4 times as much power as you pedal yourself.
• Battery: Every E-MTB motor draws its energy from the battery. The E-MTB batteries usually come from the motor manufacturers themselves and cannot be combined with other E-MTB motors or models. E-MTB batteries are available in various sizes and shapes. Batteries attached to the outside of the frame can only be found in inexpensive E-MTBs. Almost all manufacturers now rely on partially or fully integrated batteries for their E-MTBs. The capacity of the E-MTB battery is decisive for the distance you can cover with the E-MTB with one battery charge. The capacity of the lithium-ion battery is given in watt hours (Wh). The following applies: the larger (i.e. more capacity) the E-MTB battery, the heavier it is. A good guideline for high-quality E-MTBs is a capacity of around 600-750 watt hours.
• Display / remote control: In addition to the motor and battery, the E-MTB drive system also includes a display and (in some cases) a handlebar remote control. Depending on the E-MTB motor manufacturer, this can be a minimalist control element with LED lights or a fully-fledged bike computer with a large color display and smartphone-like functions.
• Background noise: There are clear differences in how loud or quiet an E-MTB motor is. The Brose Drive S Mag is one of the quietest of the classic mid-motors. Only light E-MTB motors from Fazua and TQ are even quieter (here we have a special light E-MTB article for you).
• App configuration: The Shimano motors in particular offer an app for extensive configuration of the motor characteristics. In sporty use, this is definitely an important factor, where the industry leader Bosch has not really excelled yet.

These manufacturers build the best E-MTB motors

While in the past there was often no getting around the E-MTB giant Bosch. But a lot has happened on the E-MTB market in recent years. More and more E-MTB motor manufacturers and brands are entering the market with their special drives. In the table below, we provide you with a overview of which manufacturers you should have on your radar when it comes to drives for E-mountain bikes. We deliberately left out small, unimportant E-MTB motor manufacturers or E-MTB front-wheel drives. This makes it clearer and you can focus on the models of E-MTB motors that really play a role in sporty E-mountain bikes.

Bosch E-MTB motors

The German manufacturer Bosch is one of the most important suppliers of E-MTB motors. Bosch has been involved in the E-MTB market since 2010, so the know-how of the market leader for e-drives is very large. With the constant development of its Performance Line CX E-MTB motor, the Swabians have also had a decisive influence on the evolution of E-mountain bikes. The latest expansion stage of the Performance Line CX motor is already in the fourth generation. The smart functions, the special E-MTB riding mode and an optional E-MTB ABS are unique on the market. The cheaper Active Line motors from Bosch are mainly found in trekking bikes.

Shimano E-MTB motors

Shimano is one of the largest and most powerful bicycle companies in the world. Especially when it comes to gears, drives and brakes, the Japanese are the market leaders. In 2016, Shimano released the Steps E8000 E-MTB Motor. The Shimano E8000 debut promptly laid the foundation for a new generation of sporty E-mountain bikes. Compared to Bosch, this motor is much smaller and opens up completely new design options for manufacturers. Today, the lightweight, compact Shimano EP8 – the successor to the E8000 – is one of the best-selling E-MTB motors ever. But with the EP801 presented for 2023, which has been improved above all on the software side, Shimano is already preparing for the next few years. One disadvantage of the Shimano motors: When riding downhill, there is rattling.

Yamaha E-MTB motors

The Japanese company Yamaha has a long tradition in E-MTB motors. The e-drives from Yamaha all have the abbreviation PW, which stands for “power” and is intended to underline the performance of the pedelec motors. The brand Giant, in particular, consistently relies on Yamaha motors. With Giant E-MTBs, the PW-X e-drives from the Japanese are called Syncdrive, because they are made by Yamaha specifically for Giant.

Brose E-MTB motors

The German automotive supplier Brose has been involved with E-MTB motors for years. With the Brose Drive S Motor, the Berliners have a powerful mid-mounted motor for sporty E-mountain bikes in their range. The powerful Brose Drive S is available in two versions: with an aluminum housing and with a lighter magnesium housing (Drive S Mag). The Brose Drive T motors with 70 Nm torque are also installed in inexpensive Rockrider E-MTBs from Decathlon: An advantage of Brose motors. Thanks to the unique belt technology, the Brose motors are the quietest motors on the market.

Panasonic E-MTB motors

The electronics giant Panasonic from Japan has various middle motors and front motors for E-MTBs on offer. However, only the Panasonic mid-mounted motors of the GX series are interesting for sporty E-mountain bikes. The latest version of the Panasonic motor goes by the model name GX Ultimate Pro and is mainly installed in Flyer E-MTBs.

Specialized E-MTB motors

Ever since the American bike manufacturer launched its first E-mountain bike, the Turbo Levo, in 2015, Specialized has also relied on its own E-MTB motors – exclusively mid-mounted motors. The hardware for the Specialized e-drives is supplied by Brose or Mahle. Specialized develops software, controls and batteries itself in Switzerland. The Specialized E-MTBs with their mid-mounted motors stand out from the crowd, especially in terms of battery integration, app control and riding characteristics. The light Specialized SL 1.1 motor was presented in 2021 and was developed together with Mahle. Here is an overview of the most important E-MTB motors from Specialized:

More exciting E-MTB motors

In addition to the market leaders Bosch and Shimano and the E-MTB motors presented above, there are a number of other e-drives that are installed in sporty E-mountain bikes. For example, the Canadian bike brand Rocky Mountain has been developing its own mid-motor for its Powerplay E-MTBs since 2017, which is called Dyname. The highlight of the Rocky Mountain drive concept: In contrast to other mid-motors, the bottom bracket axle is not driven, but the Powerplay E-MTB motor is located slightly forward in front of the bottom bracket. In addition, some manufacturers rely on the extremely powerful Sachs RS E-MTB motor. With a torque of 112 Nm, the Sachs RS is more powerful than most other mid-mounted motors and, as an open system, can be combined with many battery and display types. Here are the most important facts about other E-MTB motors at a glance: