What is a Motorcycle Swingarm and How It Works?

Investing in a vehicle can be a tough decision, and it is thus important to know about all its essential components for making an informed choice. Motorcycles are built of some complicated components, and one such includes its rear suspension system. 

A swingarm or a swinging arm holds the rear axle firmly, allowing the vehicle to move seamlessly.

In simple terms, a bike swingarm is a single or double-sided mechanical device. It is a thick rectangular piece of metal attached to the rear wheels from the chassis and is responsible for holding its rear wheels properly to ensure safe and smooth rides. 

A bike can smoothly pivot vertically with the help of the swingarm, as it holds the rear wheels with the bike's body. 

Various materials and components can contribute to creating a swingarm. In most cases, these are made of aluminium for motorcycles. Its low weight and strength are some factors that help a swingarm be effective. 

Besides that, manufacturers also use steel to create swingarms, mainly keeping durability in mind. 

In some rare cases, manufacturers use carbon fibre to create a bike swingarm. This material is popular for its strength and effective performance quality. However, it is quite expensive and can be difficult to procure.

A swingarm is an H-shaped or L-shaped suspension part connecting a bike's chassis with the rear wheels. A swingarm pivot bolt attaches it to the body of the motorcycle. This allows both the rear wheels and tyres to move up and down smoothly with the road undulations. 

The main role of a swingarm is to firmly hold and attach the rear wheels to the body of a bike. It maintains a conjunction with a shock and spring. The chain pull flexes the swingarm to the left when the rider twists the throttle. 

This way, a rider faces minimum road impact and can pivot horizontally easily.

A motorcycle shares some common components with cars, such as engines, brakes, wheels and tyres, headlights and taillights, etc. However, there are some key differences between the two types of vehicles, one of these being the swingarm. 

A bike swingarm helps to hold a rear axle and rear suspension together. Without this component, the rear tyres can be detached easily from the body, which is dangerous while riding.

Now that you know the meaning of bike swingarm, it is important to dig deep into its details and importance in motorcycle functioning. Here are the two basic categories of a swingarm:

1. Single-sided Swingarms

The introduction of this type of swingarms occurred back in 1940. This design helps the swingarm of a bike to hold the axle, chain, and sprocket in place, allowing its wheel to pop off the axle easily. 

As a result, chain maintenance and rear wheel removal become much easier. While this type of swingarm ensures the highest performance quality, their usage is quite limited, restricted only to higher-end motorcycle models. 

2. Double-sided Swingarms

This type of swingarms is easy to mass produce, mainly for being cheap and rigid. With a double-sided setup, such swingarms are commonly used in most motorcycle models in the current scenario. Vehicle lovers often feel that such a design can affect the appearance of a bike negatively while increasing its maintenance. However, it is much more affordable. 

Additionally, there are three different types of motorcycle swingarms based on the specific requirements of the bike. 

Here are the types based on structure and functions:

3. Swinging Fork

This structure of a swingarm includes a pair of parallel pipes connected to both ends of a bike. These are responsible for holding the rear axle at one end and pivoting the other end. Usually, this design is necessary if a bike requires a dual suspension setup for having a heavy body. Manufacturers often use two shock absorbers below the seat rail in such a design.

4. Cantilever

This structure is an extension of the previous one, whereby a triangular frame is used to compress the shock absorbers of a bike. It transfers the load to the rear shock. The shock absorbers are usually mounted right in front of the swingarm for this purpose. You can see this type of design commonly in bikes with mono shocks.

5. Parallelogram Suspension

Parallelogram Suspension, also known as Parallelogrammo, was first launched in 1985. This type of swingarm is a thick metal block, making it look like a Parallelogrammo. Manufacturers usually connect two frames with this structure for additional stability. Such a suspension is effective to avoid any unexpected torque reactions to ensure a smooth riding experience.

It is important to consider the length of swingarm when choosing a new motorcycle. This is mainly because the length and physical appearance of a swingarm can affect the ability of a motorcycle to put its power on the road. 

Usually, a shorter swingarm is preferable as it keeps the wheelbase compact in a motorcycle. It also improves the quick handling functions, as naturally lower objects are required to be moved from one place to another. 

On the other hand, a longer swingarm is effective for improving off-the-line acceleration. The motorcycle and engine power distribution is better in a longer length. Thus, it is important to consider the length of the swingarm while purchasing a new bike.

You might have come across the term extended swingarm, particularly if you are into racing, and wondered about its meaning. This term is associated with sports bike drag racing. This type of swingarm improves the performance of such bikes while extending its overall footprint. This ensures better stability and off-the-line traction.

Recently, such swingarms have started gaining popularity among bike enthusiasts who wish to see exceptional looks and performance from motorcycles. With varying degrees of build quality, these can contribute to improved efficiency of the bikes and enhanced experience of riding. 

If you are purchasing a new bike, make sure to check and choose a suitable swingarm based on your requirements.