What Is Pedal Assist Electric Bike and How it Works

When you think of electric bikes, you might think of the large, clunky versions that people use for commuting. However, there is another type of electric bike – the pedal assist electric bike. This is a smaller and more lightweight bike that still has an electric motor to help you out when pedaling. So, what is a pedal assist electric bike? Read on to find out!

Electric bikes have provided the world with the best environmentally friendly form of convenient commute.

With millions of e-bikes being manufactured and sold annually, this industry has experienced significant growth. Market insights show that in a decade, the global e-bike market would reach nearly US$40,000 million.

There are two main kinds of electric bikes available in the general market. One type of e-bike is a pedal-assist bike, while the other is a throttle e-bike.

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Both electric bike types have their unique characteristics, features, uses, and benefits.

What is a Pedal Assist Electric Bike?

As the name suggests, pedal-assist electric bikes require pedaling assistance to keep moving.

Pedal-assist electric bikes are similar to conventional bikes. However, their added electric motor assistance makes them a part of the electric bike category.

These electric bikes need to be pedaled in order for the motor to be activated. Once the motor turns on, electric power aids the rider. This electrical aid allows the rider to ride more leisurely.

Pedal-assist electric bikes are the most common kinds of electric bikes that you see. They allow the rider to benefit from the physical pedaling while offering electrical convenience.

Continue reading below to learn about how pedal-assist electric bikes work.

Read How to Charge an Electric Bike Battery at Home?

How do Pedal Assist Electric Bikes Work?

Pedal Assist Electric Bike Modes

A pedal-assist electric does not work like a motorbike or a throttle bike. The pedal assist’s electric motor does not turn on by a button or lever. Rather, the electric bike’s motor turns on after it senses pedaling.

These electric bikes usually have three kinds of pedal assist modes. To activate either of the three modes, the rider needs to keep pedaling.

The first or the lowest mode allows the minimum electric motor assistance. As a result, the rider does most of the work themselves. In order to reach higher speeds, the rider must pedal faster.

The second or the middle pedaling assistance mode offers a medium level of electric assistance. Such an electric bike would not completely depend on the rider’s pedaling.

Moreover, the added electrical motor assistance means the electric bike would have a higher speed.

The third or final level offers the maximum level of electrical assistance. The rider would have to pedal very little and enjoy a fast ride.

However, going on this mode for longer can deplete your electric bike’s battery pack more quickly.

Some pedal-assist electric bikes are designed for a more adventurous trail. Such e-bikes often have more additional electric assistance modes.

The additional mode allows the e-bike to work similarly to a motorbike. This allows the electric bike to go at the highest possible speed with barely any pedaling.

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Read How to charge an Ancheer Electric Bike

The Bosch Pedal Assist Electric Bike

For example, the German Bosch electric bike comes with more than the three standard modes. Other than the regular three modes, the e-bike has one more mode.

This additional mode allows the e-bike to be more powerful and faster for rugged terrains. These electric bike mode levels are Eco, Tour, Sport, Turbo.

The first mode is the Eco level, which uses minimum electrical assistance. At this mode, the e-bike’s speed depends highly on the rider’s pedaling ability.

On the other extreme is the last level called the Turbo mode. This mode offers the rider maximum electrical assistance and speed.

The table below shows Bosch’s e-bike modes and their added electrical power assistance. Moreover, it also shows the maximum speed each mode can offer.

The numbers shown below are for a flat landscape ride. These numbers and speeds vary depending on whether the terrain is steep or rough.

Bosch Pedal Assist Electric Bike ModesAdditional Electrical Power Assistance (%)Top Average Speeds on Flat Surfaces (miles/hour)
Eco Mode40%15
Tour Mode100%20
Sport Mode150%28
Turbo Mode225%30

The Electric Bike Pedal Assistance Mechanism

The pedal-assist electric bikes don’t need an additional throttle button or switch. Rather, the pedal sensors in the e-bike automatically turn the motor on when the pedaling starts.  

Most pedal-assist electric bikes have either a torque or cadence sensor. Some electric bikes have a combination of both.

Read How Heavy is an Electric Bike?

Cadence Sensor System

These sensors are mostly built inside the electrical motor. However, they can also be present on the axle or shaft of the e-bike. The sensors allow the e-bike to pick up on the pedaling motion.

The cadence sensors pick up on the forward pedal rotation when a rider starts pedaling. Once it successfully senses that, it automatically turns the electric motor on.

The meter or setting system attached to the e-bike allows the rider to choose the mode. If the rider wishes to pedal more, they can simply select the low mode through the meter.

This sensor mechanism will not alter the motor power depending on your pedaling. Rather, it will continue to provide the motor level power you have selected on the settings.

Hence, regardless of your pedaling, the selected mode will allow and restrict the power that comes through.

The table below shows the pedal assistance speed of a KBO e-bike, using the cadence sensor. This electric bike has five power assistance modes.

KBO Electric Bike Power-Assist ModeMaximum Speed (Miles/Hour)
PAS 18
PAS 211
PAS 314
PAS 417
PAS 520

Torque Sensor System

The other type of sensor is the torque sensor. This sensor mechanism is more advanced and modern than the cadence sensor system.

The torque sensor of the e-bike is also able to sense the pedaling force. Hence it too can pick the pedaling sensation and automatically turn on the motor.

The difference with this system is that the torque sensor detects the rider’s pedaling force. It then increases and decreases the electric assistance depending on the rider’s pedaling power.

This means that the electrical power assistance would vary simultaneously with the force the rider exerts.

The rider can view the power usage, speed, and battery charging on the attached LCD display.

Regardless of the mode or sensor system, the bike will require more electrical power to go up a slope. Similarly, lesser electrical power would be used to go down a slope.

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Benefits of Pedal Assist Electric Bikes

Pedal-assist electric bikes have helped the world step into the future of commuting. These e-bikes come in different sizes and designs and are excellent for short trips and longer commutes.

In comparison to fully electric throttle e-bikes, pedal-assist e-bikes offer many benefits. Some of these benefits are elaborated below:

Convenient Riding

Bike riding can be both relaxing and great for physical health. Having a bike allows a person cost-effective transport, which is both calming and efficient.

However, riding a normal bike for too long can be tiring for the rider. Moreover, high speeds are impossible to maintain when the bike is dependent on the rider’s capabilities.

A pedal-assist electric bike is a solution to all possible biking problems. It allows a person to reach their destination without getting too tired.

The electrical assistance gives the rider an additional boost. This boost allows the rider to enjoy a smoother ride regardless of the terrain.

Some people cannot enjoy a bike rider due to physical pains and unhealthy joints. Since a pedal-assist electric bike puts no stress on the joints, everyone can ride them.

Furthermore, many throttle or fully electric bike riders often have to carry extra battery packs. Not doing so could leave them stranded.

With a pedal-assist electric bike, the rider does not have to worry about that.

Read Can I Overcharge An E-Bike Battery?

Improved Physical Health

Riding a regular bike could be too physically exhausting for most riders. On the other hand, riding a fully electric bike would allow no physical exercise.

Hence, a pedal-assist electric bike offers the best possible balance. Since the motor’s activation depends on the rider’s pedaling, the rider muscles will be used.

The pedaling offers a great cardiovascular workout and burns extra calories. Hence, the rider can improve their physical health without getting too worn out.

These e-bikes offer an effective workout to people who otherwise cannot ride due to physical disabilities.

A research conducted at Brigham Young University further proved the associated health benefits. It stated that riding a pedal-assist e-bike offers the same workout as riding a mountain bike.


Riding a pedal-assist e-bike leaves no carbon footprint, making for an eco-friendly commute. This quality makes these e-bikes a great alternative to using a car.

Countries with more people riding such e-bikes need fewer public transport vehicles. As a result, the carbon emissions are controlled, and the environment remains cleaner.

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Improved Battery Life

Nearly all modern electric bikes come with a lithium-powered battery pack. These battery packs have a limited life per charge and a limited total lifespan.

On average, an e-bike battery would last five to seven hours on one charge. Moreover, the average battery lifespan is four to six years.

The battery’s life depends on many factors:

  • Pedal assistance
  • Battery type
  • Battery size
  • Rider’s weight and riding style
  • Charging practices

Having pedal assistance in your electric bike positively affects the battery life and total lifespan. Since the e-bike uses the rider’s pedaling, the battery does not deplete too quickly.  

This means that the rider can get farther without stopping to recharge. Moreover, the added pedaling option means the rider does not carry an extra battery pack.

Since every recharge negatively affects the battery’s range and capacity, pedal assistance can avoid that. As a result, the battery’s range, performance, life per charge, and total lifespan remain high.

Furthermore, knowing you can still pedal to your destination if your battery runs out is reassuring.

Check out, How Fast Can You Go On An E-Bike?

Improved Mental Health

Nothing could help a mind relax more than an effortless bike ride.

Any kind of bike riding can be therapeutic and relaxing. However, when a person gets too tired and worn out, the relaxing effect decreases.

Hence, riding a pedal-assist electric bike allows the rider to relax without getting physically stressed.

With an e-bike, more people can enjoy a bike ride. Hence, more people can experience its therapeutic benefits.

Faster Commute

When a person rides a regular bike, their speed and acceleration may continuously vary. This is because it is almost impossible for an average human body to maintain its performance.

On average, a rider’s biking speed could vary between ten to thirteen miles/hours. The more the rider pedals, the more tired they get. As a result, their speed decreases.

Riding a pedal-assist electric bike allows the rider to be more speed consistent and smooth.

When the rider gets tired, they can switch to a higher pedal assistance mode. Doing so would allow greater electric assistance, and hence, increases the speed.

Read How Much Does It Cost to Rent An Electric Bike In the United States?

Safe Riding

Having a pedal-assist electric bike means that you are better able to keep up with the fast traffic. This otherwise is not possible with a regular bike.

With a pedal-assist electric bike, you can accelerate and can stay clear of other vehicles.

What is a pedal-assist electric bike
What is a pedal-assist electric bike


Using public transport for daily commute can be expensive for many people. Moreover, using your own car means affording the rising fuel expenses.

Having a pedal-assist electric bike allows you to save on fuel and public transport money costs. Moreover, since pedal-assist e-bikes do not require frequent battery charging, riders save on charging costs.

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Final Thoughts

Pedal Assisted electric bikes are modern and futuristic transport vehicles. These electric bikes can truly add to a rider’s life and riding experience in many ways.

The pedal assist electric bikes are ideal for both shorter and longer commutes. They allow riders to enhance their mental and physical health without compromising their joints and muscles.

Pedal-assist electric bikes protect the battery and prove to be more cost-efficient. They are eco-friendly, offering faster and safer rides.