Electric bike motor: which one to choose?

When you're looking to get an electric bike, it's not always easy to focus on the motor and understand its important parameters. However, the electric bike motor is crucial to ensuring your e-bike delivers complete satisfaction. Which model should you choose, based on which criteria, and how to navigate the brands on the French market? Here's an overview.

Electric bicycle motor: 3 selection criteria to know

1. Engine power

One of the most fundamental characteristics of an electric bicycle motor is its power, measured by the amount of energy delivered in a given time. Indeed, it is this power that will determine whether your bike is suitable for your use. From a legal point of view, the European standard NF EN 15 194 limits the power of an electric bicycle motor to 250 W (watts) and its electric assistance to 25 km/h. This is the case for most e-bikes sold in France. However, beyond this power or this speed exceeded when pedaling, the cycle model falls into the moped category, with obligations to be met such as registration, mandatory helmet wearing, and insurance. This applies to bikes equipped with 500 W, 750 W, or 1000 W motors, and those with a maximum authorized speed of 45 km/h, such as speed bikes.

📖 Also read: Torque and motor power of an electric bike: what you need to know

2. Engine torque

Expressed in Newton-meters (Nm), torque indicates the rotational force of the electric bicycle motor. It is decisive when starting, climbing or accelerating. The higher the torque, the easier it will be to start, climb and accelerate. Therefore, the use of your electric bicycle (daily commute, transporting children, shopping or loads, sports or leisure use for example) as well as the gradient of your planned journeys (flat, with or without occasional hills, hilly, steep terrain or mountain) are important criteria in the selection of the e-bike motor.

To know which electric motor to choose based on its torque, here are some guidelines:

• On flat terrain without gradients (slopes less than 3%), for urban use and leisurely rides with smooth and progressive electric assistance, a torque of 30 to 50 Nm will be sufficient.
• For a journey with a more hilly gradient (slopes between 3 and 8%), occasional sporty outings, a torque of 50 to 65 Nm will be more appropriate.
• On steep terrain (slopes greater than 8%) and for electric mountain bikes, a torque of at least 70-90 Nm will be essential because it offers more powerful assistance on hills and sporty acceleration.
• For mountainous terrain or an electric cargo bike, the ideal minimum torque is 85 Nm. Being heavier and more heavily loaded, this bike model requires electric assistance adapted accordingly. For significant hills along the way or when transporting more than a hundred kilos, it's better to aim for a 130 Nm motor, like the one powering Galian's Formidable.

💡 Tip: To calculate the gradient of your electric bike journey and view the elevation profile, you can use the BRouter tool: once you have completed your route, simply click on the “mountain” icon at the bottom right!

image: valeo cycle engine, exploded view

3. The location or type of the electric bicycle motor

In order to choose the right motor for your electric bike, it is important to differentiate between the existing types according to their location on the bike: motor located in the front wheel, the rear wheel or in the crankset (central motor), or even twin motor.

The front wheel motor

The advantage of an e-bike motor located in the front wheel is that it's economical, simple, and discreet. It may be suitable for occasional use and light urban bikes, but it's less powerful and less suited to uphill riding and rougher terrain. Furthermore, its location can make the traction feel less natural when riding. In addition, the weight distribution on the bike is less optimal and can lead to imbalance.

The rear wheel motor

Easy to use, the electric bike motor located in the rear wheel is also often more affordable than a mid-drive motor. It is therefore preferred for small budgets, city bikes, on flat terrain or for touring. It can also be offered as a conversion kit, to transform a muscle bike into an electric bike.

However, like the front-wheel motor, the rear-wheel motor will tend to unbalance the ride due to the weight at the rear, with a feeling of forward thrust, which may nevertheless suit some. Its limited power also makes the bike less efficient on hills.

The twin-engine

Some brands also offer a dual motor on their electric bike models, that is to say the addition of two motors generally located in each wheel, one at the hub of the front wheel, the other in the hub of the rear wheel.

Compared to a single front-wheel/rear-wheel motor, this combination delivers greater power, better distributed across both wheels, thus reducing the risk of slippage or premature wear of a single motor. Furthermore, traction is improved because the two drive wheels, under the effect of combined traction and propulsion, provide better grip, particularly on slippery roads or off-road. It thus ensures greater safety by preventing skidding in these conditions.

The electric twin motor can be interesting for cargo bikes and fat bikes because it ensures stability and assistance even with a heavy load. It is also suitable for mountain bikes or trekking bikes, on muddy and sandy paths and on steep slopes.

On the other hand, the dual-motor electric bike is heavier, which can affect handling. On the other hand, it generates increased energy consumption and therefore reduces the range by putting more strain on the battery. Finally, they are generally more expensive to purchase, but also to maintain due to their more sophisticated electronic management.

Image: Le Formidable cargo bike, equipped with a 130Nm central motor

The mid-engine or central motor

Located at the bottom bracket, the central motor has multiple advantages. Since assistance is directly transmitted to the bike's transmission, its efficiency and autonomy are optimized, while the pedaling sensation is very natural. Balance and maneuverability are ensured thanks to the centered weight. Its assistance is progressive in effort and proportional to the pedaling force. It is also more powerful when climbing or in hilly or even mountainous terrain and its torque is generally higher. The bottom bracket motor is therefore equipped on the majority of high-end electric city bikes, electric mountain bikes, trekking bikes and cargo bikes. Downsides: it is more expensive to purchase and maintain, and can lead to faster wear of the transmission (chain and cassette) when it is a derailleur or hub with integrated gears and not a belt.

➡️ Little pro tip 😉: to choose a good electric bike motor, check for a torque sensor (not just cadence or rotation), it will provide more natural assistance!

Finally, in addition to the power, torque and location of the electric bike motor, other aspects can help in choosing a model: its autonomy (a motor with more torque consumes more), its noise (a central motor is generally quieter than a motor located in the wheel), its maintenance and its proven reliability over time.

Electric Bicycle Motor Brands and Models

Several brands are present on the French market and offer a variety of engine models. Here are their main features:

Bafang

This entry-level to mid-range Chinese brand offers a wide range of mid-drive motors, as well as front and/or rear wheel motors. Bafang offers the advantage of being versatile and offering good value for money. It's possible to transform a regular bike into an electric bike using conversion kits that allow you to electrify a model, for which the Bafang brand is particularly well-known. However, its after-sales service varies depending on the manufacturer.

Yamaha

In the mid- to high-end segment, Yamaha, a Japanese brand, stands out for its powerful, torquey, naturally responsive pedal-driven motors, while also being particularly quiet and compact. This brand is renowned for its smoothness and precision.

Shimano

The Japanese brand Shimano offers mid-range to high-end mid-drive motors. Their integration is made easier when the electric bike's drivetrain is also from the same brand. The Shimano Steps range is known for its smooth assistance and lightweight design, making it well-suited to touring bikes and some electric mountain bikes. The overall performance of Shimano motors is balanced. However, some versions may have less torque.

Brose

Brose is a German brand of mid-drive motors for electric bicycles. Situated at the high end of the market, they are very quiet, customizable, and include an internal belt with "belt drive" technology. However, they are less common and require more specialized maintenance. The Drive S Mag motor has experienced reliability issues in the past, including premature belt breakage and mechanical failures, which have since been resolved through a software update, hardware reinforcement, and a remanufacturing program.

Bosch

Originally from Germany, the Bosch brand occupies a high-end position in the electric bicycle motor market and enjoys a good reputation, renowned for its reliability and performance. Its mid-drive motors equip urban e-bikes (Active Line / Active Line Plus range), mountain bikes and sports bikes (Performance Line / Performance Line CX range) as well as cargo bikes (Cargo Line). A Bosch electric bicycle motor has many strong points: its reliability, its smooth assistance, an extensive after-sales service network and compatibility with many bikes. On the other hand, its price is high and the possibility of customization is limited.

Valeo

A leader in the field of vehicle electrification, the French brand Valeo recently developed a market-first electric motor for bicycles, in partnership with another French company, Effigear. Indeed, the Valeo Cyclee electric bicycle motor directly integrates an automatic gearbox into the crankset. A world first on an electric bicycle, this seven-speed gearbox automatically adapts to the cyclist's behavior and can even anticipate it with the "predict" mode, adjusting the electric assistance, frequency, and pedaling rhythm smoothly and optimally, thanks to an algorithm associated with this system. The cyclist's effort is thus reduced by 8. Its recent update allows the pedaling cadence to be adjusted between 15 rpm and 90 rpm between gear changes. By eliminating a more traditional derailleur transmission or separate gearbox, it is both simple to use and maintain.

image: Valeo Cyclee central engine integrated into a Galian cargo bike

This model also boasts unrivaled features: thanks to its 130 Nm torque, 48 volt electrical voltage and 250 watts of nominal power, it is currently the most powerful electric bicycle motor on the market. It can therefore easily climb slopes with a gradient of more than 14% or parking ramps. A "boost" function, activated using a trigger, also allows for quick and powerful climbing of hills or overtaking.

This French electric bike motor is therefore versatile for urban or sporty use, but also particularly suited to mountain terrain and uneven or difficult terrain, or even for cargo bikes thanks to its carrying capacity of up to 200 kg of payload. For all these reasons, Galian has chosen to equip its electric cargo bike, the Formidable, with this cutting-edge Valeo Cyclee motor.

So, to choose your electric bike motor well, you should take into account its power, torque and location on the cycle, but also select the brand and model adapted to the trips you intend to make. As you will have understood, the best electric bike motor is the one that corresponds most perfectly possible to the use of your bike (urban, sport, transport of people or loads), the terrain (flat, uneven, with more or less pronounced gradients, occasionally or constantly), your preferences in terms of pedaling sensations and your budget.

Don't hesitate to try out different electric bike models by comparing their motors, ideally in real conditions via a loan or rental, to make your final choice!

One last piece of advice: make sure that a qualified local bike shop or network knows how to maintain your bike and its associated engine: peace of mind guaranteed!