Dirt bike riding is a thrilling and adrenaline-packed experience. Every year, dirt biking draws lots of riders. These riders often bank on their bikes providing them with the power and speed they need to win races. Hence, one of the most common questions asked by beginners and enthusiasts is How fast can a dirt bike go?
How fast is a dirt bike is a question that can be answered after considering several factors. Chief among these factors is the engine size capacity of the dirt bike. Dirt bikes are manufactured with varying engine sizes. They include the youth 50cc and 65cc bikes to the more advanced 85cc. Adult bikes like the 250cc and 450cc dirt bikes are also available.
How Fast is a Dirt Bike?
Regardless of the engine size of a dirt bike, there is a certain speed range peculiar to a particular bike class. For instance, it would be outrageous to expect a speed of 70mph (113 km/h) from a 50cc. Even if the engine were modified to deliver more power and acceleration, that speed is too high for such a kid bike.
So, how fast do dirt bikes go? Let’s explore some of the popular bike classes based on engine size and their typical speeds:
50cc
The 50cc bikes are designed for younger riders. That is mostly the beginner riders between the ages of 4-7 years. These bikes have a maximum speed of around 35-48 mph (56-77 km/h).
65cc
This engine size is commonly used in motocross bikes. It has a top speed of around 45-55 mph (72-88 km/h). Some bike brands and riders can drag a speed of 60mph (97 km/h) out of this bike class. These bikes are designed for younger riders who are more experienced. Such riders have usually developed more advanced riding skills.
85cc
Another popular size for motocross bikes is the 85cc engine. It can reach speeds of 60 mph (97 km/h). They are also commonly used by younger, more experienced riders. These are riders who have progressed beyond the 65cc bikes.
110cc
The average 110cc dirt bike has a top speed within the range of 50-55 mph (80-88 km/h). The bikes that fall in this class are mostly off-road bikes. They are built for off-road riding.
Some of the top brands in this class include: Kawasaki KLX 110, Honda CRF 110F, Yamaha TTR 110 and Kawasaki KX 112. Out of these four 110cc dirt bikes, only the Kawasaki KX 112 is a motocross bike.
In general, 110cc bikes are great beginner bikes. A popular choice among users who want to focus on off-road riding is the Kawasaki KLX 110. They are ideal for kids aged 8-12 years old. Even better, some popular models come fitted with electric starters. There are also some with a manual clutch. This is helpful for kids who are transitioning from automatic bikes.
125cc
There are many varieties of 125cc engine-size dirt bikes in the market. Unlike the smaller bikes in the junior category, the 125cc bike can come with a 4-stroke engine.
This has an impact on the speed the bike is capable of. 4-stroke engines are known for their relatively low torque and power generation. This is when compared to a 2-stroke engine.
These bikes are often used for both off-road and on-road riding. Regardless of who asks how fast is a 125cc dirt bike, it can reach speeds of up to 70-80 mph (113-129 km/h).
They are also commonly used for racing. These bikes are a popular choice for adult beginners who are looking for a faster and more powerful bike.
150cc
How fast is a 150cc dirt bike? A 150cc dirt bike can top out at about 50-60 mph (80-97 km/h). But, as a much bigger bike, it may be possible to ramp up the speed beyond this limit. This is dependent on the skill of the rider in controlling the bike. Also, the terrain you ride the bike on factors in as well.
250cc
These bikes are manufactured for more experienced riders. But really, how fast is a 250cc dirt bike? They can reach speeds of up to 75-90 mph (121-145 km/h). They are mostly the common choice for racers.
450cc
These bikes are more powerful and are for experienced riders. It is best suited for riders who are looking for a more aggressive ride. They can reach speeds of up to 90-110 mph (145-177 km/h) and are commonly used for racing. These bikes can also handle weightier riders.
650cc
These bikes are even more powerful than the 450cc bikes. They are rare but when you see them, they are handled by experienced riders. Such riders are looking for a high-performance bike with a high top speed.
As one of the fastest dirt bike in the world, they can reach speeds of up to 110-130 mph (177-209 km/h). These bikes are best for long-range races and they can tear through desert settings.
Top Speed for Safe Dirt Bike Riding
The dirt bike top speed can vary widely depending on many factors. These factors include such as the engine size, and the gearing. There should also be considerations for the aerodynamics of the motorcycle. This is in addition to the weight of the rider. Road conditions/terrain have a role to play as well.
For instance, a dirt bike will readily reach top speed on a paved road than it would on a dirt track. Let’s have a closer look at some considerations you should look into when looking out for the top speed of a dirt bike:
Engine size and gearing
In general, the larger the engine size, the faster the dirt bike can go. But, other factors like the aerodynamics of the bike can determine the top speed.
For example, a motorcycle with a larger engine may have a higher top speed. But if it is not aerodynamically efficient or has a low gear ratio, its top speed may be limited.
This is why most racing dirt bikes have a streamlined body shape. This is a targeted design aimed at improving the aerodynamic quality of the bike. By doing so, the cruise speed of the bike is ultimately upped.
Legality
It’s noteworthy that while a bike may reach a certain top speed, it may not be legal to do so on public roads. The speed limit on most roads is well below the top speed of most motorcycles. Exceeding the speed limit can result in fines or license suspension.
Skill level and experience
Acceleration and handling are also important considerations when choosing a bike. These factors are mostly dependent on the skills of the rider. Hence, the skill and experience of the rider should be considered when choosing a fast bike. A more powerful and faster dirt bike poses a more challenging ride. It will require a higher level of skill and experience to operate safely.
Safety
Dirt bikes can be dangerous. Riders should always wear appropriate safety gear and should always follow safe riding practices. This includes helmets, gloves, boots, and protective clothing. They mitigate the risk of injury in the case of an accident. This involves obeying race rules and bike maintenance. Even riding defensively has proven to avert more riding accidents.
Comparison Table of Speed by Engine Size
| Bike Engine Size | Speed (mph) | Speed (km/h) |
| 50cc | 35-48 | 56-77 |
| 65cc | 45-55 | 72-88 |
| 85cc | 60 | 97 |
| 110cc | 50-55 | 80-88 |
| 125cc | 70-80 | 113-129 |
| 150cc | 50-60 | 80-97 |
| 250cc | 75-90 | 121-145 |
| 450cc | 75-90 | 121-145 |
| 650cc | 110-130 | 177-209 |
Factors Affecting Dirt Bike Speed and Performance
Many riders and motorcycle enthusiasts believe the bigger the bike, the faster it will be. This is based on the popular opinion that the bigger bikes have bigger engines. This, therefore, means that these big bikes will be capable of more speed.
As simple enough as it may seem, multiple factors can affect the speed and performance of a dirt bike. Some of these factors include:
Type of Engine
The type of engine can affect dirt bike speed and performance. Engine type can be either a 2-stroke or 4-stroke. Each type of engine has its own merits and pitfalls. 2-stroke engines are lighter and simpler than 4-stroke engines. This makes them faster and more responsive. They have fewer moving parts. This reduces the weight of the engine and allows for higher revving speeds.
This is also why 2-stroke engines are ideal for motocross. They have a good combination of speed and agility which are essential in racing. But 2-stroke engines tend to be less fuel-efficient. They produce more emissions than 4-stroke engines.
4-stroke engines are heavier and more complex than 2-stroke engines. They have more moving parts. This provides smoother power delivery and better low-end torque. But while 4-stroke engines are more reliable and durable, they are not as fast as 2-stroke engines.
Rider Weight and Height
Rider weight and height factors in when it comes to dirt bike speed and performance. The weight and size of the rider can affect the bike’s acceleration and top speed. Their impact is even telling on the handling and maneuverability of the bike. All these can affect the speed and performance of the bike.
Here are some ways that rider weight and height can impact dirt bike performance and speed:
Acceleration
Fast acceleration is dependent on the weight of the rider. The weight of the rider can affect how quickly the bike accelerates. A massive rider may require more power to get the bike moving. This can result in slower acceleration times. Similarly, a lighter rider may be able to accelerate faster. This is due to the bike having to move less mass.
Top speed
The weight of the rider can also matter in determining a bike’s top speed. A heavier rider can increase the overall weight of the bike. This can reduce the bike’s top speed due to added drag and resistance. Additionally, a larger rider may present more wind resistance to the bike. All these can also affect the top speed of the bike.
Handling
Rider weight and height can also influence how well a bike handles. A rider who is too heavy or too tall for the bike may have trouble maneuvering it effectively. This not only impacts its speed but also its performance.
But it is not only the bigger riders that may experience a challenge handling a bike. A rider who is too light may have trouble controlling the bike in rough terrain. In some cases, they may be thrown off the bike. These factors affect the stability and performance of a bike.
Maneuverability
The weight and height of the rider can also affect the bike’s maneuverability. A rider who is too tall may have trouble fitting on the bike and controlling it effectively. While a rider who is too short may have trouble reaching the controls. This makes it difficult to maintain proper balance.
Riding Techniques
A rider’s skill level can also influence a dirt bike’s speed. Experienced riders who are confident in their abilities can ride faster than beginners. This is because they are more comfortable pushing their bikes to their limits. They can also understand the terrain better. This capacity allows them to apply their controls more appropriately. Thus, reaching a higher speed.
Also, riders more skilled in shifting gears and using the brakes can improve their speeds. Mastery of all these controls helps the rider adopt faster and better riding techniques. Learning how to properly shift gears and use the clutch. Or how to control the throttle can help riders achieve faster speeds.
Leaning into turns and using body positioning to control the bike is also helpful. It aids the riders in maintaining stability and control while riding.
Brand of the Bike
The brand of the dirt bike can be a factor that affects its speed and performance. Different brands have different engineering focuses. For example, some brands may prioritize speed and power. Others may focus on durability and reliability. Cheapest bikes usually won’t offer speed.
On a similar note, some brands may specialize in certain types of terrain such as motocross or trail riding. KTM’s tagline is “Ready to race”. They make high quality motocross dirt bikes. This can affect the bike’s performance in those specific environments.
Moreover, different brands use different materials and manufacturing processes to produce their bikes. The result is quite telling on the bike’s weight, strength, and overall performance.
Some brands may use lighter materials such as aluminum. This helps to reduce weight and increase agility. Others may use heavier materials such as steel to improve durability and stability.
For example, the KTM brand suspension system is famed to be the best. This guarantees a smooth and stable ride. Shocks and impacts from rough terrain are also well absorbed. This in turn improves speed and performance. It does this by allowing the rider to maintain control and stability.
Final Words
One of the most significant factors that determine how fast a dirt bike can go is the type of terrain it’s ridden on. Flat and straight dirt roads or tracks provide the best environments for high speeds. Riding on rough, rocky terrain or steep hills can slow down a dirt bike. So, when choosing a fast bike, consider all these factors that can affect its speed.
FAQs
How fast does a 650cc dirt bike go?
A 650cc dirt bike can go as fast as 110-130 mph (177-209 km/h)
How fast does a 450cc dirt bike go?
A 450cc dirt bike can go as fast as 75-90 mph (121-145 km/h)
How fast does a 250cc dirt bike go?
A 250cc dirt bike can go as fast as 75-90 mph (121-145 km/h)
How fast does a 150cc dirt bike go?
A 150cc dirt bike can go as fast as 50-60 mph (80-97 km/h)
How fast does a 125cc dirt bike go?
A 125cc dirt bike can go as fast as 70-80 mph (113-129 km/h)
How fast does a 110cc dirt bike go?
A 110cc dirt bike can go as fast as 50-55 mph (80-88 km/h)
How fast does an 85cc dirt bike go?
An 85cc dirt bike can go as fast as 60 mph (97 km/h)
How fast does a 65cc dirt bike go?
A 65cc dirt bike can go as fast as 45-55 mph (72-88 km/h)
How fast does a 50cc dirt bike go?
A 45cc dirt bike can go as fast as 35-48 mph (56-77 km/h)
