Electric bikes are becoming increasingly popular for their convenience, low environmental impact and fuel economy. But how does an e-bike work? In this guide we explain everything you need to know to understand how they work and make the most of their benefits. You’ll learn about the essential components that make up an electric bike and how they interact with each other to make it work, so you can make an informed decision when buying an electric bike or electric bike conversion kit.
What is an e-bike?
In simple terms, an electric bike is one that is powered by an electric motor that assists the rider in pedalling. The motor is powered by a battery that is charged from the mains and can provide pedalling assistance for several kilometres or more than 100 km. The motor is activated when the rider starts pedalling, and the system senses the force applied to the pedals to adjust the motor speed. The rider can adjust the motor speed via a controller attached to the handlebars.
The main components of an electric bicycle
Electric bicycles have several main components that differentiate them from conventional bicycles. These components include an electric motor, a battery, a controller and a pedal sensor.
Electric Motor
Without a doubt, the motor is one of the fundamental components in the operation of an electric bicycle. It is responsible for providing pedalling assistance and is what differentiates it from a conventional bicycle. There are three types of motors: those located in the hub of the front or rear wheel and those located in the centre of the bicycle, in the bottom bracket axle.
The type of motor used in your electric bike affects its efficiency, durability and feel:
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Front wheel hub motor
This is the simplest and most affordable location. It does not interfere with the bike chain or pedals. A front hub motor works via a sensor that detects how much power to send to the motor based on the speed at which you pedal. Restarting after a stop sign, yield sign or roundabout is easy. On the other hand, a smooth or sandy surface can be uncomfortable and make the bike a bit unstable – ideal for city riding!
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Rear wheel hub motor
Integrated with the bike’s gears. This connection improves traction, ride behaviour and provides a sense of thrust. Power transfer is efficient, but unfavourable gear ratios within the motor can lead to overheating during long climbs. This type of engine is suitable for all types of terrain, both for touring and urban use.
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Mid-drive motor
The electric motor is located next to the pedals, in the centre of the bike. The electric bike is stable, easy to handle and the support is proportional to the pressure exerted on the pedals. These motors can be mounted on almost any type of bike, from city bikes to high-end mountain bikes. Perfect for medium and long distance rides.
The battery is a key component of electric bicycles
The battery is another key component of an electric bicycle. It is responsible for storing the electrical energy needed to provide pedal assistance. The battery powers the motor and determines the overall range. It is important to ensure that the battery has sufficient capacity to meet your daily needs.
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Battery capacity and types
There are different units for measuring electricity: power, voltage and ampere-hours. Using these values, you can choose the right battery capacity for your electric bike. Note that most e-bike batteries have a capacity of between 250 and 750 watts.
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Position and weight of the battery
To prevent the heavy bike component from disturbing your balance, it has a low, centred position. Although batteries have become smaller and more powerful since lead-acid batteries were replaced by lithium-core batteries, they still add a lot of weight to the bike. Therefore, not just any battery can be used for an electric bike.
To avoid feeling weighed down, it must be light and powerful at the same time. Older electric bikes are often equipped with lead-acid batteries, which are heavy and store less energy. Today, electric bikes no longer use lead-acid batteries, but if you’re looking for a second-hand bike, you should consider lithium-ion batteries.
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Battery types
Lithium-ion batteries are lightweight but expensive. They can power your bike for tens of kilometres on a single charge and last between 500 and 1,000 charge cycles. It takes between 3 and 6 hours to charge them using conventional plugs. Just like a mobile phone, the battery is plugged into a normal power socket.
Of course, it is possible to ride without electric assistance if the battery fails or discharges along the way, but the weight of the electric bike will be felt. Pedalling is not impossible, but it is more complicated.
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Charging capacity and durability
When choosing an electric bike, it is important to consider battery capacity and charge life. Battery capacity is measured in watt-hours (Wh) and determines how much energy it can store. The charge duration is measured in kilometres (km) and determines how far you can travel on a single charge.
How does an e-bike battery work?
Batteries work by converting stored chemical energy into electrical energy. Inside a battery there are two electrodes, a cathode and an anode, separated by an electrolyte. When the battery is connected to a circuit, a chemical reaction takes place between the electrolyte and the electrodes, causing electrons to flow from the anode to the cathode, generating an electric current.
The answer varies based on the type of electric bike that you own:
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Pedal-assist
Pedal-assist electric bikes are a popular type of electric bike in which the electric motor is activated by pedalling. This system provides an extra boost of power to the bike, making it easier for riders to climb hills and ride longer distances. When the rider pedals slower, the speed of the bike decreases, which provides greater control over the power of the bike.
This feature is very beneficial, as it allows the rider to always be in control and avoid over-reliance on the motor. As a result, pedal-assist bikes have become the preferred choice of many cyclists, especially those who want to enjoy the benefits of electric cycling while still getting some exercise.
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Throttle-only
Throttle-only electric bikes are a type of electric bike that is operated entirely by a throttle instead of pedalling. When the rider twists the throttle, the electric motor kicks in and propels the bike forward. These bikes are attractive to cyclists who want to get around with little effort, but they have some drawbacks.
The main disadvantage is that they discharge the battery quickly, which can be a drawback for long journeys. Electric bikes with throttle are also subject to additional safety regulations in some jurisdictions, and riders should be aware of these limitations and safety issues before making a purchase. Nevertheless, they can be a useful option for short trips or for cyclists with limited physical capabilities.
Bike frame and drivetrain
When it comes to a bicycle frame, weight is key. A typical bicycle frame is made of aluminium alloy, which makes it light and efficient. The same is true for high-quality electric bikes: the lighter the frame, the faster the ride. The spokes must be strong enough to withstand the extra torque of the electric motor without bending or breaking. Opt for chrome, steel or brass spokes to ensure durability.
The drivetrain refers to the pedals, chainrings, cranks, chain and gears that work together to move your electric bike in the right direction. The pedal-assist motor directly drives the drivetrain, making it easy to shift gears and pedal efficiently. This is one of the reasons why pedal assist motors are a popular choice for riders looking for efficiency.
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Brakes
Electric bikes can easily reach high speeds and are heavier than normal bicycles, making them potentially dangerous without a reliable braking system. Hydraulic disc brakes are a favourite among the e-bike community because they stop quickly in all weather conditions. The brake pads require very little maintenance and have good stopping power, but not as much as hydraulic disc brakes. They are installed on the hub or rim of the bike and require the use of a cable.
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Controller
The controller is the central device that connects the motor, battery and other components of the electric bicycle. Typically located on the handlebars, it controls the speed and power of the motor and displays information such as speed, distance travelled and battery charge. Acting as the brain of the system, the controller regulates the electrical signal to ensure a smooth and controlled ride. A high quality controller is essential for the electric bike to overcome hills and long distances with ease.
Different types of assistance for electric bicycles
As electric bicycles gain popularity, pedal-assist systems have become the norm. They generate power for the drivetrain through the pedals. There are two main types of electric assist systems.
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Non-proportional assistance: Pedal Sensor
Non-proportional assistance on e-bikes is provided by a pedal sensor, also known as a magnetic or rotation sensor. This type of sensor provides continuous assistance when the rider pedals and the sensor detects the magnets attached to the chainring. However, the motor assistance stops as soon as the rider stops pedalling.
A limitation of this system is that the motor performance is not affected by pedalling pressure and does not adapt to the terrain. It is up to the rider to select the level of assistance required, which can range from eco to tour to turbo mode.
The most common assistance modes are:
- Eco Mode: This mode is designed to help riders conserve their battery by providing up to a 50% reduction in power usage. This mode is ideal for riders who want to extend their range or conserve battery power for longer rides.
- Tour mode: Tour mode is best suited for cyclists riding on winding or hilly roads. This mode provides a power output that is 120% of the rider’s input, making it easier to tackle difficult terrain. Tour mode is a good choice for riders who want to balance speed and efficiency.
- Turbo mode: Turbo mode is the most powerful mode available on most electric bikes. In this mode, the motor delivers a maximum power output of 300%, at the cost of reduced battery life. This mode is best suited to riders who need an extra boost of power to cope with steep inclines or strong headwinds.
Despite this limitation, the magnetic pedal sensor is a popular choice for riders who want a simple and reliable power assist system. It can be especially useful for riders who prefer a constant level of assistance or for those who don’t want to fiddle with the controls.
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Proportional assistance: Torque sensor
Non-proportional assistance on e-bikes is provided by a pedal sensor, also known as a magnetic or rotation sensor. This type of sensor provides continuous assistance when the rider pedals and the sensor detects the magnets attached to the chainring. However, the motor assistance stops as soon as the rider stops pedalling.
A limitation of this system is that the motor performance is not affected by pedalling pressure and does not adapt to the terrain. It is up to the rider to select the level of assistance required, which can range from eco mode to tour or turbo mode. Despite this limitation, the magnetic pedal sensor is a popular choice for cyclists who want a simple and reliable system of electric assistance. It can be especially useful for riders who prefer a constant level of assistance or for those who don’t want to fiddle with the controls.
Regenerative braking
Many electric bicycles also have regenerative braking. This system harnesses the kinetic energy generated when the rider brakes and uses it to recharge the battery. Regenerative braking is an excellent way to extend the range of an e-bike, as it allows the rider to recover some of the energy that would otherwise be lost when braking.
What is the Bafang e-bike conversion kit and why is it an excellent choice?
The Bafang electric bicycle conversion kit is a set of components that can be installed on a conventional bicycle to convert it into an electric bicycle. These kits typically include an electric motor, battery, controller and other items necessary for the conversion.
The Bafang electric bike conversion kit is an excellent choice for those who want to convert their conventional bike into a high quality and efficient electric bike. With a powerful motor, durable battery and efficient controller, these kits provide a smooth and comfortable electric cycling experience.
Conclusion
Electric bikes are an excellent choice for those looking for a sustainable, economical and comfortable means of transport. Now that you know how an electric bike works, you can take advantage of all its benefits and enjoy a unique riding experience. Remember that it is important to choose the right model for your needs and to carry out regular maintenance to ensure it works properly.
FAQ
How much are electric bikes?
The cost of an electric bike can vary depending on the model and brand. In general, electric bikes cost more than conventional bikes, and can range from 500 to 5000 euros or more. However, the price can be offset in the long run by savings in fuel and maintenance.
How fast do electric bikes go?
The maximum speed of electric bicycles is limited by law in most countries, and is usually around 25 km/h. However, some high-performance electric bike models can reach speeds of up to 45 km/h. It is important to remember that the maximum speed may also be limited by factors such as battery capacity and motor quality.
Can you take an electric bike on a train?
In general, yes, but it is important to check the specific regulations of the railway company and the country you are in. Generally, a reservation is required, there are size and weight restrictions, and some parts of the bicycle may need to be disassembled. Additional fees may also apply.