E-bikes are rapidly gaining popularity across virtually all cycling disciplines – and now account for over a quarter of new bike sales annually in the UK. They are a great alternative to traditional or ‘analogue’ bikes for a number of reasons. They provide a more effortless and efficient mode of transportation, can allow riders to travel further, faster than before and can provide a route back into cycling following injury or poor health and fitness. They also happen to be really fun!
This is all great, but as a consumer where do you start? The choice and breadth of models now available can be daunting. There are a number of different motor types available and defining which one works best for you is a great starting point (from there you can focus in on bike styles and brands). Each motor type has its advantages and disadvantages depending on the application. Today we'll take a closer look at e-bike motors, their differences, and which one is best suited to your needs.
First, let's define what an e-bike motor is. It’s an electric motor that powers an e-bike via a battery and can be positioned in numerous places on the bike. It provides extra assistance when pedalling, making it easier to ride (particularly up hill) and more efficient. The rider must still put in some effort through the pedals to access the assistance, so you do get a workout, but it all feels that bit easier. There are three main types of e-bike motors: front hub, rear hub, and mid-drive – let’s dig in and have a look at them.
Front Hub Motors
Front hub motors are located in the centre of the front wheel and provide propulsion by driving that wheel only. They are easy to install and are typically less expensive than other motor types. However, front hub motors can suffer the same issues as a front-drive car – with less traction on slippery surfaces and steering that can be corrupted by the electric power. There is also more weight over the front of the bike, which is not ideal for handling balance.
Examples of front-hub bikes: Brompton electric
Rear Hub Motors
Rear hub motors, as the name suggests, are located in the rear wheel. They provide propulsion by driving the rear wheel, making them inherently more stable and providing better traction on slippery surfaces. Rear hub motors are also easier to install than mid-drive motors. They may not provide as much torque as mid-drive motors, so the correct application is important. Rear hub motors are ideal for road bikes as the higher speeds negate the need for lots of pulling power and their placement means integration on the bike can be almost imperceivable at first glance.
Examples of rear-hub bikes: all road bikes, Boost conversion kits
These motors are located near the bike's cranks and provide propulsion by driving the chain directly (along with your legs), making them very efficient. They provide the highest torque and power figures, making them ideal for steep hills, rough terrain or lugging heavy loads. The ideal applications for mid-drive are therefore mountain bikes and cargo/family bikes. With the motor mounted low down and right in the centre of the bike, mid-drive bikes offer the best handling and ride balance. Downsides? They tend to be more expensive than alternatives and require the whole bike to be built around the motor – so no conversions here. Bosch and Shimano motors are kings of the mid-mount game.
Examples of mid-drive bikes: all MTB, cargo, family, hybrid
Another important factor to consider when choosing an e-bike motor is the level of assistance it provides. E-bike motors come with different power ratings, which determine the level of assistance. The power rating is measured in watts, and the higher the wattage, the more assistance the motor provides. However, higher wattage motors can be more expensive and drain the battery faster.
To recap, when choosing an e-bike motor, it's important to consider your needs, the terrain you'll be riding on and how far you want to travel. If you're looking for a more affordable option and mostly ride on flat terrain, a front hub motor may be the best choice. If you need more stability, traction and speed, a rear hub motor is ideal. If you plan to ride on steep hills or rough terrain with loads of kit, a mid-drive motor will provide the necessary torque and power. So there you have it, e-bike motors explained. Think carefully about how and where you’ll be using your bike before taking the plunge and you can’t go wrong.