Parts of a bicycle and their functions: everything you need to know

28 November 2023

Whether you are an occasional rider or a passionate cyclist, understanding the different parts of a bicycle is essential.

From the frame to the pedals, every component plays a crucial role in the performance and functionality of the bicycle.

In this article we will explore the different parts of a bicycle and delve into their significance.

Hop on and join us on our journey through the anatomy of a bicycle!

Infographic of a bicycle with all parts defined.

In this image you can see a complete x-ray of the parts of a bicycle.


The bicycle frame is the main component that determines its structure and geometry.

Constructed from materials such as steel, aluminum, carbon fiber or titanium, the frame plays a critical role in rider comfort and performance.

A well-designed frame allows for a balanced distribution of body weight, facilitating an ergonomic position and minimizing fatigue during longer rides.


The fork, located at the front of the bike, plays a crucial role in absorbing vibrations and shocks from the terrain.

Its design and construction allow the rider to experience a smooth and controlled ride, even on uneven surfaces.

Forks are usually made of materials such as steel, aluminum or carbon fiber, the latter being the lightest and strongest option. There are two types: rigid forks and suspension forks.


The rims, spokes and hubs make up the wheel, and combine to give stability and support to the bicycle.

  • The rim: is the outer circle of the wheel that holds the tire in place and provides a base for the brake shoes to grip.
  • Spokes: thin rods that connect the rim to the hub and balance and strengthen the wheel.
  • The hub: located in the center of the wheel, it houses the bearings and facilitates their rotation.

As for wheel size, it is an important factor.

Smaller wheels, such as those on folding bikes or children’s bikes, increase maneuverability and agility.

On the other hand, large wheels, such as those usually found on mountain or road bikes, ensure better balance and the ability to roll effortlessly over obstacles.

Tubes and inner tubes

The tires and tubes of a bicycle are essential components responsible for both the performance and safety of the ride.

Their rubber exterior makes them tough and durable, while they are available in different widths and patterns to suit different driving conditions.

In addition, the air chambers, which are usually made of lightweight butyl rubber, are inflated to provide the necessary air pressure.

Some types of tires are:

  • Deck tires.
  • Tubeless tires.
  • Cross-country tires.
  • Trail tires.
  • Downhill tires.
  • Gravel tires.
  • Snow Tires.

For example, for rocky or uneven surfaces, wider tires with a more aggressive tread can provide greater traction and stability.

In contrast, smoother roads or pavements require narrower tires with a softer tread to reduce rolling resistance and increase speed.

Transmission and connecting rod

The drivetrain, consisting of the chain, sprockets and chainrings, is responsible for transferring the power generated by the rider to the rear wheel.

The chainrings, located on the crank, convert the circular motion of the pedals into the turning of the chain.

On the other hand, the crank, made of materials such as aluminum or carbon fiber, acts as the direct connection between the pedals and the chainrings, optimizing power transfer and allowing smooth, lossless pedaling.

Infographic of bicycle transmission parts


The pedals of a bicycle are essential for the rider to transfer the power from his legs to the drivetrain.

Attached to the cranks, they rotate in a circular motion as the rider pedals.

There are different types of pedals:

  • Platform pedals: which provide a simple flat surface on which the feet rest.
  • Clipless pedals: which require special cycling shoes with cleats that attach to the pedals, providing a more secure connection.
  • Clamp pedals: which incorporate an adjustable strap to keep the front of the foot in place.


The gears on a bicycle are an essential system that allows the rider to adjust resistance and speed according to the terrain and his or her pedaling pace.

The shifting system generally consists of a rear derailleur and one or more front derailleurs, together with a shifter located on the handlebars.

When changing gears, the derailleur moves the chain from one sprocket to another on the rear wheel or from one chainring to another on the crank, altering the gear ratio.


Brakes are essential components on a bicycle that ensure the rider’s safety and control. There are different types, such as rim brakes and disc brakes.

Rim brakes are common and lightweight, ideal for dry conditions. While disc brakes offer more power and performance in difficult terrain and wet conditions.

When applying the brakes, it is essential to do so gradually and evenly to avoid skidding or loss of control. Hard braking can cause the wheels to lock up, resulting in a lack of traction and stability.

Handlebar and stem

The handlebars, which are usually made of strong materials such as aluminum or carbon fiber, are the part of the bicycle that the rider grips and uses to steer the bike .

The stem connects the handlebars to the fork of the bicycle. It adjusts the angle and height of the handlebars, allowing the rider to discover the most comfortable and ergonomic riding position.

The handlebars and stem work together to provide stability and control on the bike, ensuring a pleasant and enjoyable ride.

Two of the most common types of handlebars are:

  • Drop handlebars: usually found on road bikes. These handlebars offer multiple hand positions, allowing the rider to improve aerodynamics and decrease wind resistance.
  • Flat handlebars: usually seen on mountain bikes. These handlebars provide a more upright riding position, providing better control and stability when riding in difficult terrain.

Saddle and seat post

The saddle, located at the top of the seat post, is the main point of contact between the rider and the bicycle.

There are different types of saddles, some are focused on comfort and have additional padding, while others prioritize lightness and aerodynamics with a slimmer, more minimalist design.

On the other hand, the seat post allows the height and angle of the saddle to be adjusted.

They are made of different materials, such as aluminum, steel and carbon, which affect their weight, stiffness and vibration absorption capacity.

Specific parts of an electric bicycle

  • Control panel: Through the control panel, you can turn the electric motor on and off, adjust the pedal assistance and control the speed. In addition, it can display relevant information such as battery level, speed, distance traveled and other data related to the operation of the electric bicycle.
  • Controller: Acts as the brain of the system, receiving information from sensors and sending commands to the engine and other components. The controller manages speed, pedal assist and other parameters, providing precise and safe control of the electric bicycle.

  • Lithium battery
    The lithium battery of an electric bicycle is a rechargeable device that stores the electrical energy used to power the bicycle’s electric motor. It is composed of lithium cells that offer high energy density and a long service life.
  • Pedal sensor: The pedal sensor of an electric bicycle is a device that detects and records the rider’s pedal movements. This sensor sends signals to the electric bike controller to activate the electric motor according to the selected pedal assistance.
  • Motor: The motor provides the power and electrical impulse. It can be located on different parts of the bicycle, such as the rear wheel hub, bottom bracket or front wheel. The motor uses electrical energy from the battery to generate power and pedal assistance, allowing the rider to overcome steep slopes or reach higher speeds with less effort.

Infographic with the parts of an electric bicycle

Other elements

There are many other elements that can make up a bicycle, depending on the type of bicycle you use, some of them are:

  • Bottom bracket: Set of bearings and shafts that connects the cranks to the bicycle frame.
  • Shift levers: Allows shifting gears and controlling the derailleur.
  • Rear derailleur: The mechanism that moves the chain between the different sprockets on the rear wheel.
  • Brake levers: These are the levers located on the handlebars that are used to operate the brakes.
  • Grips: Grips located at the ends of the handlebars for comfort and grip.
  • Rear shock absorber: A suspension system located at the rear of the bicycle, under the saddle, that provides shock absorption in difficult terrain. The right saddle can make the difference between a smooth ride and an uncomfortable experience.


There are a variety of items that can help cyclists enjoy their rides even more.

  • Lock: A lock is essential to protect your bike when it is parked or unattended. Cable, U-shaped and chain padlocks are available in different shapes and sizes.
  • Air pump: An air pump is also an important accessory, as it allows the tires to be inflated to the recommended pressure.
  • Lights: In addition, bicycle lights are necessary for visibility and safety, especially in low light conditions or at night. They can be mounted on the front and rear of the bicycle, and have fixed and flashing modes.
  • Bells: Bicycle bells or horns can be attached to the handlebars, allowing cyclists to alert pedestrians and other cyclists.
  • Bags: Bicycle bags or baskets are practical for carrying things like shopping or personal belongings.
  • Water bottle holder: A holder on the bicycle frame that allows you to carry one or more water bottles.
  • Kickstand: A folding stand at the rear of the bicycle that allows it to be parked in a stable position.
  • Mudguards: They are installed on the wheels to avoid water splashes and dirt.

The importance of knowing the parts of your bicycle

In summary, knowing the parts of a bicycle and understanding their functions is essential to maximize performance, safety and rider comfort.

Every component, from the frame to the brakes to the wheels, plays an important role in the riding experience.

Proper maintenance and care of each part ensures optimum performance and prolongs the life of the bicycle.

Ultimately, becoming familiar with these parts allows cyclists to have greater control over their experience on the road and fully enjoy the benefits of cycling whether for sightseeing, as a means of transportation or for sport.

Knowing the parts of a bike is likehaving a map to explore the world of two wheels, you’ll never get lost on the way to the fun!

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