What Is the Relationship Between Motorcycle Engine Size (CC) and Speed?

A majority of people, even most motorcyclists, believe that a large-displacement engine means more speed. It is true only to a certain extent. If you started your motorcycling career with a 125 cc motorbike, any upgrade to either a 300 cc or a 500 cc motorcycle will be a lot more for you. A 300 or a 500 cc motorcycle will be much quicker than a 125 cc.

However, this is not always true. A bigger motorcycle engine doesn’t guarantee top speeds. It depends on the motorcycle type, purpose, and build. There are various factors other than the motorcycle engine size that govern the speed of a motorbike.

Continue reading this article to learn in detail about the relationship between motorcycle engine size (cc) and speed.

Motorcycle engines come in different sizes and types. However, the most common characteristic is its size, also known as the “Displacement Size.” It is measured in centimeter cubes (cc) and cubic inches (cu in). It is measured in the unit of volume of the gas displaced per cycle. The bigger the size of the engine, the more gas can be displaced.

When the fuel is burnt inside the combustion chamber, it is converted into a mixture of gases and is displaced out of the engine through the exhaust pipes. The temperature and pressure inside the engine increases as the fuel is burnt.

The pressure of the expanding gases makes the parts move inside the internal combustion engine (ICE) in a motorcycle. This, in turn, produces mechanical energy, which is then transferred to the transmission and eventually to the rear wheel.

As per the definition, speed is the rate at which a distance is covered. The smaller the time is, the more will be the speed.

Speed = Distance / Time

S = D / T

S (m/s) = D (m) / T (s)

A motorcycle that can cover a distance in less time will have a better top speed. Meanwhile, a motorcycle that takes more time to cover the same distance is said to be slower.

Considering that the two motorcycles belong to the same category, they have similar basic designs, engine types, and aerodynamics. The motorcycle with the larger engine displacement will have more speed.

Considering the above considerations, a 1,000 cc motorcycle can reach a top speed of around 140 mph. Meanwhile, a 600 cc motorcycle can reach a top speed of 100 mph.

What if the two motorcycles are from different categories? What if they have completely different riding styles, aerodynamics, and design?

In this case, the motorcycle with a bigger engine size doesn’t necessarily go faster than the motorbike with a smaller engine. A smaller-engine motorbike can go faster if it has better horsepower and aerodynamics.

The Kawasaki Ninja H2R features an iconic 998 cc Supercharged inline-four cylinder engine. It is the fastest production gas-powered hypersports bike that can attain a top speed of 250 mph. If this bike competes with the Kawasaki Ninja 650 in a race, it will easily win the race. The Kawasaki Ninja 650 features a 649 cc parallel-twin engine that is substantially less powerful and smaller than the Ninja H2R’s engine.

However, if the Kawasaki Ninja H2R competes with the Harley-Davidson Street Glide, which has an engine size of 117 cu in (1,923 cc), in a race, the Ninja H2R will easily win. Even though the H-D Street Glide has a substantially larger engine, almost double in size, than the Ninja H2R, it is not built for high-speed performance.

If it is not the engine size that always influences the motorcycle speed, then what does? There are many factors that influence motorcycle speed. Let’s discuss each of them below:

Design plays a crucial role in the performance of a motorcycle. You can just look at a motorcycle and tell whether it is built for speed or not. A motorcycle that is extra large in size with a longer wheelbase and raked-out front-end is meant for better linear performance and for comfortable highway cruising. There are no such hints of aggressive styling on such bikes.

Meanwhile, a motorcycle with an aggressive design and features is meant for high speeds.

The Harley-Davidson Street Glide is a touring bike. It is a bigger motorcycle with a long wheelbase, height, and stature. The handlebars are reasonably taller and swept back for an upright riding stance. The foot controls are mounted forward to ensure comfortable legroom. Overall, the Street Glide is designed for comfortable touring. It is not meant for speeding.

On the contrary, a smaller motorcycle with aggressive styling, like the Kawasaki Ninja H2R, is built for speeding. By only looking at the design of this bike, you can tell that it is meant to be ridden on race tracks.

Sports bikes have designs that promote better airflow and sportier riding style. They are mostly designed for sports racing on paved tracks and drag racing. There are several high-performance superbikes that can even compete and win against top-end performance cars in drag racing.

Touring bikes, like the Harley Road Glide are tuned for comfortable rides and longer distances. They are meant to cover long miles comfortably.

There are also many added accessories and parts installed on touring bikes and baggers to make them touring capable. These include a wide fairing, infotainment system, saddlebags, crash bars, sissy bars, backrests, and floorboards.

On the contrary, a sports bike is meant for quicker rides. It offers a highly aggressive riding stance as the rider has to lean forward and the legroom is highly restricted. Sports bikes are one of the most uncomfortable bikes in terms of ergonomics and riding position. These bikes are not meant to be comfortable.

The weight of a motorcycle also plays a crucial role in influencing its speed.

A heavier motorcycle, like a touring bike or bagger, tends to be slower than a sports bike. They have dozens of extra touring parts that add more weight to the bike.

In addition to being slower, heavyweight motorcycles also tend to be less agile and maneuverable. It is difficult to lean them around corners and change directions. This is why touring bikes require expertise to handle and maneuver them safely, especially while turning corners. Slow-speed maneuvering becomes more challenging as the weight becomes more evident.

Meanwhile, the sports bikes are lighter compared to touring bikes and cruisers. Weight alone cannot guarantee top speeds. A lightweight motorcycle needs to have better aerodynamics, power-to-weight ratio, and horsepower to be the fastest. However, weight is an important factor. A lightweight motorbike requires less power and effort to be pushed forward at a good speed when throttle is opened. 

Another very significant factor that makes a motorcycle attain high speeds is its aerodynamics. Aerodynamics refers to the characteristics of a motorcycle that let the air around it pass through smoothly without providing much air drag.

A motorcycle is said to have better aerodynamics if the air drag is minimal. The frictional or resistance force, also known as the air drag, limits the motorcycle’s capability to go at high speeds. The engine will have to deliver more power and work harder to overcome the drag.

A touring bike, like the Street Glide or Indian Challenger, or a cruiser, like the BMW R 18, are not designed aerodynamically. If you ride these motorbikes at full throttle, you will experience the maximum air drag. These heavyweight, bigger motorbikes are very difficult to ride in windy conditions.

A high air drag can also cause wind buffeting that results in severe turbulence at different motorcycle parts. A high air drag while riding a touring bike can also destabilize the ride and cause you to lose control. To block the incoming wind from hitting your face and helmet, riders install windscreens on the touring bike.

On the other hand, sports bikes are designed to have the best aerodynamics. They offer the least air drag to the motorcycle and rider. It is mainly because the rider sits in a forward riding position and is attached to the bike to act as a single unit. Better aerodynamics means the engine power is not wasted in overcoming the air drag.

If you want to learn about the relationship between motorcycle engine size (cc) and speed, it is important that you know the Horsepower Vs Torque relationship. The most important characteristics of a motorcycle that everybody would want to know are horsepower and torque.

Horsepower has the main role to play when it comes to motorcycle speed. The more the horsepower is, the more will be the top speed of a motorcycle.

However, a bigger-displacement motorcycle engine doesn’t necessarily mean that it will produce more horsepower. It depends on the construction of the engine and how the engine is tuned.

Horsepower is defined as the rate at which the torque is applied or delivered. It is the ability of the motorcycle engine to rapidly produce more revolutions of crankshaft in less time.

The faster the crankshaft and piston revolve around the crank axis, the greater will be the motorcycle speed.

This is the reason why the Kawasaki Ninja H2R can easily beat the Harley-Davidson Street Glide in a race. The Ninja H2R’s 998 cc Supercharged engine produces much greater horsepower than the Street Glide. The Street Glide has no chance to beat or even come near the Ninja H2R.

On the contrary, a motorcycle with greater torque can accelerate quicker and can carry more load. High torque improves acceleration and throttle response. Meanwhile, horsepower improves motorcycle speed.

The Street Glide and other touring bikes have bigger engines, meaning bigger bore and stroke sizes. The piston rods and the distance between the crank pin and the crank axis in large-displacement touring and cruiser bikes are also greater compared to sports bikes, resulting in greater torque figures.

These large-displacement touring bikes can accelerate quicker, and the force with which the engine pushes the bike forward is much stronger.

There are many advantages of higher cc motorcycles, including:

• More torque.
• Better acceleration.
• More strength.
• The high force with which the engine pushes the bike forward.
• The throttle response is also quick.
• The bike feels much more responsive than a smaller cc motorbike.
• A higher cc motorcycle is also perfect for long-distance rides.
• You can comfortably take a higher cc bike on a motorcycle tour.
• You can also carry more load on a higher cc bike.

Yes, the engine displacement (cc) affects the fuel consumption. A motorcycle with a higher cc engine tends to be larger and have more volume. It also has bigger engine cylinders that draw in more fuel than a small cc engine.

A large-displacement motorcycle engine tends to produce more power and torque. It requires more energy to convert it into the mechanical force that drives the rear wheel. This energy comes from the fuel.

Yes, the engine size has a good impact on the rpm it produces. A motorcycle engine with a small piston crown and small piston rod will tend to move in a rotational motion more rapidly than a higher cc engine with a longer stroke and piston rod size.

The distance between the crank pin and crank axis will also be smaller in a smaller engine, resulting in higher rpm. An engine with a shorter stroke size will tend to rotate rapidly.

It depends on the riders’ skills and purpose of motorcycle riding. For a beginner who has just started riding a motorcycle, a 125 cc motorcycle like the Honda Grom is an ideal option. For a beginner who knows the basics, a 300-500 cc motorcycle is perfect. However, the safety precautions and traffic laws must not be avoided.

Meanwhile, if you are an intermediate rider, you can ride a 1,000-1,300 cc motorcycle easily, considering it is a cruiser motorcycle. It highly depends on what type of motorcycle you are riding. If it is a superfast sports bike, a 1,000 cc bike, like the Kawasaki Ninja H2R, it is not safe for you to ride such a bike. Only professionally trained sports bike racers should ride such motorcycles because they are extremely fast.

However, if you are looking for a cruiser or a touring bike, you can ride a bike as big as 1,900 cc, considering your skillset and how much weight you can handle.

A 1,000 cc cruiser or touring bike is much slower than even a 600 cc sports bike. However, many cruisers and touring bikes are mostly heavier for beginners to handle and balance. You must consider a bike's engine size, weight, handling, and comfort before purchasing it.

When we were new to motorcycling, we all thought that having a bigger motorcycle engine meant more speed. However, we were not very familiar with how the engine actually works and what the role of engine size is. Also, we always thought that only power matters. As we grew, we realized that horsepower and torque are two different things.

The relationship between motorcycle engine size and speed is directly proportional to a certain extent, considering we are assuming similar motorcycles from the same category. A motorcycle with a higher cc engine will tend to have more speed.

However, it is not always true, if we are considering two motorcycles from different categories. A touring bike with a higher cc engine is slower than a sports bike with a comparatively smaller engine.

Nonetheless, a touring bike with a higher cc engine accelerates quicker, has better throttle response, can carry more load, and can even climb hills. On the other hand, a sports bike can attain much higher top speeds than a touring bike.

Sports bikes with smaller cc engines tend to produce more horsepower. It is the rate at which the torque is applied or delivered. Sports bikes can be ridden at much higher top speeds because their engines are capable to rev higher and quicker than higher cc engines.