Home > News > News

How does a motorcycle engine work?

2023-03-02


A motorcycle generator works in the same way as a car engine. The generator consists of a piston, a cylinder block, and a cylinder head containing the valve mechanism. When a spark ignites the fuel and air mixture, it causes an explosion, pushing the piston up and down the cylinder. The valves then open and close to allow the fuel and air mixture to enter the combustion chamber. The up and down motion of the piston turns the crankshaft, converting the energy of the piston into rotational motion. The transmission transmits the rotating force of the crankshaft to the rear wheels of the motorcycle.

Cylinder

Motorcycles can have 1-6 cylinders. For years, the V-twin design was the choice of motorcycle engineers in the United States, Europe and Japan. The V-twin is named for its two cylinders in a V-shape, such as the classic Harley-Davidson V-twin shown below. Note the 45 degrees in the Harley-Davidson V-twin; other manufacturers can vary this Angle to reduce vibration.

The V-twin is just one way to line up two cylinders. If the pistons are to be positioned opposite each other, the reverse twin design should be selected when arranging the cylinders. Parallel two-cylinder engines, on the other hand, place the pistons side by side vertically.

At present, the most popular design is four cylinders. This design runs more smoothly and revs faster than a two-cylinder engine. The four cylinders can be placed side by side or arranged in a V-shape with two cylinders on each side of the V-shape.

Capacity

The size of the combustion chamber of a motorcycle engine is directly related to its output power. The upper limit is about 1500cc(cubic cm) and the lower limit is about 50cc. The latter type of engine, commonly used in scooters (motor bikes), consumes 2.35 liters per 100 kilometers and can only reach a top speed of 48-56 kilometers per hour.

Gear set

A gear set is a set of gears that can bring a motorcycle from a full stop to cruising speed. A transmission on a motorcycle usually has 4-6 gears. However, there may only be two scooters. The gear shifter can be moved within the transmission by engaging the gears with the gear shifter lever.

Clutch

The clutch's job is to engage and disconnect power from the engine's crankshaft to the transmission. Without a clutch, the only way to stop the wheels from turning is to shut off the engine, which is impractical in any type of motor vehicle. The clutch is a series of spring-loaded plates that, when pressed together, connect the transmission to the crank shaft. To shift gears, the motorcyclist disengages the transmission from the crank shaft with the clutch. Once the new gear is selected, use the clutch to re-establish the connection.

Transmission system

There are three basic ways to transfer engine power to the rear wheels of a motorcycle: a chain, a belt, or a shaft. Chain main retarder system is currently the most commonly used way. In this system, a sprocket mounted on the output shaft (i.e. the shaft in the transmission) is connected to a sprocket attached to the rear wheel of the motorcycle via a metal chain. As the derailleur turns the smaller front sprocket, it transfers power along the chain to the larger rear sprocket, which then turns the rear wheel. Such systems must be lubricated and adjusted, and replaced regularly due to chain elongation and sprocket wear.

Belt drive is an alternative to chain drive. Early motorcycles often used belts that could be tensioned with spring-loaded pulleys and handles to provide traction. Belts tend to slip, especially in wet weather, so this method is often not used and other materials and designs are used instead. In the late 1980s, material developments made the belt master retarder system feasible. Today's belts are made of rubber with teeth and work in the same way as metal chains. Unlike metal chains, belts require no lubrication or detergent.

Shaft main retarders are sometimes used. This system transmits power to the rear wheels through the drive shaft. Shaft drives are popular because they are convenient and require less maintenance than chain systems. However, the shaft drive is heavier and can sometimes cause unwanted vibrations in the rear of the motorcycle called the top shaft.

Motorcycle chassis

Seats and accessories
The seats on motorcycles are designed to carry one or two passengers. The seat sits behind the fuel tank and is easily removed from the motorcycle rack. Some have small cargo holds under or behind the seats. For more storage and saddlebags, attach a hard plastic case or holster to either side of the rear wheel or to the tailgate. Large motorcycles can even pull small trailers or sidecars. The sidecar has its own wheels for support and can be attached to accommodate one passenger.


The motorcycle chassis consists of a frame, suspension device, wheels and brakes. Each component is briefly described below.

Frame

Motorcycles have frames made of steel, aluminum or alloy. Most frames consist of hollow tubes that serve as the skeleton for mounting components such as the transmission and engine. The frame also aligns the wheels to maintain control of the motorcycle.

Suspension

The frame is also the support for the suspension system, a set of springs and shock absorbers that help keep the wheels in contact with the road and form a buffer against bumps and wobbles. The swing arm design is the most common solution for rear suspension devices. At one end, the swing arm controls the rear axle. The other end is attached to the frame by a swing arm pivot bolt. The shock absorber extends upward from the swing arm pivot bolt and attaches to the top of the frame directly below the seat. The front wheel and shaft are mounted on expansion forks with internal shock absorbers and internal or external springs.

Wheel

Motorcycle wheels usually have aluminum or steel rims with spokes, although some models introduced in the 1970s offer cast steel wheels. Cast steel wheels allow the motorcycle to use tubeless tires, meaning it has no inner tube to hold compressed air, unlike traditional pneumatic tires. Air is kept between the rim and the tire, relying on the sealed space formed between the rim and the tire to maintain the internal pressure.

Tubeless tires are less likely to blow than those with inner tubes, but problems can occur on rough roads because small bends in the rim can lead to deflating. Various tire designs can meet the requirements of different terrain and driving conditions. For example, dirt road motorcycle tires have deep knobby tread to create maximum grip on dirt or particles. Touring motorcycle tires are made of hard rubber and usually provide less grip but last longer. Despite the small surface area, sport and race tires (typically radial tires with wire straps) provide amazing grip.

Brake

Motorcycles have brakes on both the front and rear wheels. The motorcyclist uses the handle on the right handlebar to activate the front brake and the right pedal to activate the rear brake. Drum brakes were commonly used before the 1970s, but most motorcycles use disc brakes today. A disc brake consists of a steel disc connected to a sandwich between the wheel and the brake pad. When a motorcyclist operates a brake, hydraulics controlled through the brake line cause the brake pads to squeeze the sides of the disc. Friction causes the brake disc and attached wheels to slow down or stop. Brake pads must be replaced regularly because repeated use wears down their surfaces.

We use cookies to offer you a better browsing experience, analyze site traffic and personalize content. By using this site, you agree to our use of cookies. Privacy Policy
Reject Accept