Unlike the purely human-powered bicycles we usually see, electric-assisted bicycles are bicycles with electric drive, but are still mainly driven by human pedaling.

Only when actively pedaling, the electric bicycle will provide additional auxiliary power to the bicycle through the motor drive system, thus reducing the pedaling pressure of the rider and making the ride easier and less laborious.

The electric power bicycle's power gears are differentiated by application scenarios or power strength, and a variety of power gears are available to meet the multiple needs of different users.

The motor drive system of electric bicycle is the key to make electric bicycle different from other bicycles, which usually contains three parts: sensor, controller and motor.

When the rider pedals, the sensor is responsible for sensing the pedaling force and speed, and transmits the monitored speed, pedaling frequency, torque and other information to the controller, which issues commands to control the motor operation through calculation.

It is worth mentioning that most motors do not act directly on the drive train, the motor outputs power at a high speed and low torque, and needs to be amplified through a reduction system, while allowing the output speed to be close to the pedaling frequency of the human leg (mid motor) or the speed of the wheelset (hub motor).

According to a new report by Statista Research Department, the global electric-assist bicycle market reached approximately $26.5 billion in 2021. It is expected to climb at a CAGR of just under 10% from 2022 to 2030 to reach a maximum of $62.3 billion. The data shows that the global market for electric-assist bicycles is getting hotter and is quite popular among consumers.

The aforementioned ability of electric assist to help cyclists ride more easily and enjoyably is one of the reasons for its popularity. Electric-assisted bicycles are easy to get started, meeting the commuting requirements of office workers and making up for the lack of physical strength of middle-aged and elderly people, reducing travel costs, while achieving fitness goals and reducing muscle stretching damage and wear and tear on knee joints.

For keen cyclists, electric power assist can also serve training purposes, being able to maintain an even speed and smoothness through the adjustment of power assist gears, allowing cyclists to have a more humane training experience, training breathing rate and pedaling rhythm.

If you are interested in electric-assisted bicycles and want to buy an electric-assisted bicycle that suits you, then you must consider in advance what kind of role electric-assisted will play in your cycling life.

If you want to conquer more rugged roads and pursue action, competition and speed, then it is necessary to consider the climbing ability and shock effect of the electric assist bike. The climbing ability is reflected in the motor power, and the shock effect depends on the shock stroke of the electric assist.

Many high-end electric-assisted bicycles will indicate what kind of terrain and mode their products are suitable for, such as：

In 1895, the electric motor was born with the emergence of electric-assisted bicycles, and has undergone numerous evolutionary upgrades in its more than 100-year history, and has now become the "soul" of electric bicycle.

For the electric bicycle, the motor is directly responsible for the mechanical transmission, acting on the pedaling part of the vehicle to complete the conversion of electrical energy to kinetic energy, and is the ultimate tool to provide auxiliary power.

Currently on the market can be divided into two types of booster motor systems: mid-mounted and hub type.

Many enthusiasts in the purchase of electric bikes will receive such advice: to the mid-motor, not the hub motor!

In fact, the two have their own gains and losses in the comparison, we may first understand the difference between them.

Currently on the market can be divided into two types of booster motor systems: mid-mounted and hub type.

Many enthusiasts in the purchase of electric bikes will receive such advice: to the mid-motor, not the hub motor!

In fact, the two have their own gains and losses in the comparison, we may first understand the difference between them.

Hub motors are generally DC brushless motors that are mounted in the hub position of the car, and this motor acts directly on the wheel set. When riding a hub motor bike, many riders will feel a significant push and the riding experience is not natural.

But for non-mountain bikers, hub motors have the advantage of being more affordable and more in line with basic needs such as commuting.

For non-sports models, the choice of hub motor does not require a major change to the traditional frame structure, coupled with the low cost, more easily accepted by the commuting requirements of the crowd.

Motor power rating refers to the rated output power of the motor, that is, in the ideal state can be long-term normal operation of the maximum output power, also known as the "maximum use of power" (note that the rated power of the motor is not equal to the peak power).

Many riders are used to using the rated power to measure the performance of the motor, strictly speaking is not true, because it also involves the structural design of the motor, rated voltage, conversion efficiency, output torque and many other factors, even if the rated power of the same two motors, there are completely different riding experience.

General motor power has 250W, 500W, 750W, 1000W these types, some countries and regions have mandatory regulatory requirements for the rated power of electric-assisted bicycles, for example, the EU standard is rated power shall not be higher than 250W, while in some parts of the United States, this standard will be relaxed to 750W.

If it is said that the motor has become the "soul" of electric-bicycle after a century of development, then the sensor and controller working with the motor are undoubtedly the best assistants. Their application makes the electric-assisted bicycle get rid of the controversy of throttle and pedal, and really step on the development of Pedelec.

The motor drive system works in tandem that is, when the rider pedals, the sensor is responsible for sensing the pedaling force and speed, and transmits the monitored speed, pedaling frequency, torque and other information to the controller, which issues commands to control the motor operation through calculation.

Further subdivision down, the sensor and the controller's working principle is also exhaustive and worth exploring.

According to the EPAC (Electric Power Assisted Cycle) standard, electric bicycles must be started by pedaling, and if the pedaling stops, the bike must stop as well. Manufacturers are required to place a speed sensor on the pedal shaft and may also add a sensor that measures the force (torque) placed on the pedals by the rider.

While most electric bicycle users are able to change the speed of their ride on their own, more often than not, the bicycle relies on the pedaling rhythm and force felt by the sensor, which in turn controls the speed of the bicycle.

Sensors can be divided into torque sensors and pedaling sensors.

As the name suggests, the torque sensor senses how hard the rider is pedaling to obtain a high-precision torque value and thus understand the rider's riding intentions. The pedal frequency sensor is mounted on the crankset and consists of an inductive contact and a magnetic steel ring, which determines the need for boost by measuring the pedal frequency; the higher the pedal frequency, the stronger the boost.

As with any system that needs to work together, the performance of an electric bicycle starts with the accuracy of the input signal. In layman's terms, sensors are equivalent to the human sensory system, and the clearer the sensation, the better the judgment.

Torque sensors are more complex and sophisticated than torque sensors. By measuring torque, torque sensors provide more accurate input values for the controller to work with.

A high performance electric bicycle usually has more than a single sensor, but uses a combination of pedaling frequency and torque to determine the current riding status.

Take the Hummer HP eBike for example, the M510 motor has a high-precision torque and pedaling frequency sensor built in, which can accurately transmit information about the rider based on pedaling frequency and pedaling effort, helping the sensor to determine and output power.

The sensor transmits the input signal to the controller accurately. After the controller receives the torque, speed and pedaling frequency signals, it derives the output signal through arithmetic to control the motor running speed, start, stop and other various functions to guide the motor how to put out the power.

The controller is like a human brain, able to connect all electronic parts of the electric bike together, such as the battery, motor, throttle, display and various sensors, responsible for tracking the pedal activity, battery voltage, motor power, acceleration and deceleration and other important functions of the electric bike.

In addition, the controller also provides some simple protection functions, such as high-voltage and low-voltage protection of the battery to prevent the battery from being overcharged or over-discharged, and is also able to monitor the temperature and current of the motor to ensure the cyclist's riding safety through braking protection.

The controller also has the difference between sine wave and square wave, both of which have their own advantages and disadvantages, so I won't expand on that here. Many electric-assisted mountain bike players in pursuit of speed, will choose to replace the controller, but the controller wiring lines are complex, but also need expertise as an aid, the white best not to try easily.

The algorithm of the controller is what we call the control program, also known as the "invisible hand of God" by our technical department.

For example, Evolve has Eco (most economical mode), Tour (comfort mode), Sport (sport mode), Sport+ (sport enhanced mode), Boost (most powerful mode), boost mode, the choice of boost gear determines the amount of power when riding, and these all rely on the role of the program.

Transitioning from the era of bulky lead-acid batteries, most electric-assist bicycles on the market today use lithium-ion batteries, which have the advantages of light weight, high capacity and long life.

The goodness and positioning of the battery has a lot to do with these terms: voltage, capacity, energy, cell, battery pack, battery control system (BMS for short, i.e. Battery Management System)

The battery voltage of electric assist bicycle is generally between 36 and 48 volts, the battery capacity is expressed in ampere-hours (Ah), the battery capacity (Ah) × battery voltage (V) = battery energy (Wh), and watt-hour (Wh) is the unit of measurement of total battery energy.

Whether it is an external battery or a hidden battery in the frame, the "battery" we see is actually just the shell of the battery pack. The battery cell is the smallest unit in the battery, and is also the key part to determine the performance of the battery. At present, the electric bicycle on the market usually use 18650 lithium battery cells, 18650 is the specification of the cell model (cell diameter 18mm, length 65mm), this battery has a long life, high capacity per unit density, stable performance characteristics, the famous car brand Tesla on the whole vehicle using 18650 cells to protect the range.

No matter how good the quality of the cells is, there will be some errors between the cells as the use time increases. By using BMS, the damage to the battery during use can be reduced to a minimum, which is responsible for managing the charge and discharge of the battery to keep the battery in an optimal state, thus extending the life of the battery.