How Fast Does a 450cc Dirt Bike Go? [Pushing the Limit]

For many thrill seekers, there’s nothing like the rush of tearing through rough terrain on a dirt bike. For many professional riders, only a few bikes can compare to the 450cc dirt bikes. But, how fast can a 450cc dirt bike go?

A 450cc dirt bike can go as fast as 120 mph (193 km/h). This speed can depend on the bike model and manufacturing brand.

In this article, you’ll take a closer look at the speed capabilities of a 450cc dirt bike. You’ll also learn the factors that can affect it.

How Fast Can a 450cc Dirt Bike Go?

Man on motocross riding his dirt bike on the trail.

The 450cc dirt bikes are not primarily built for their speed. Their design is to tackle varying terrains. For professional riders, the 450cc dirt bikes are useful in professional racing. This is for their capacity to overcome obstacles with ease.

Yet, a 450cc dirt bike has one of the highest speeds in a dirt bike. The average speed range for a 450cc dirt bike is 97-123 mph (156-198 km/h). Their engines are powerful. They can tear through rugged tracks with lightning speed.

But this speed can be affected by a few factors. These factors can be fixed like the weight of the bike or variable like the track it is being raced on.

Factors that Affect the Speed of a 450cc Dirt Bike

Several factors affect the speed of a 450cc dirt bike. These factors include:

1. Engine power and torque

The engine power and torque of a dirt bike rely on the make and model of the bike. The reputation of the manufacturing brand has great significance in the top speed of a bike. 

Some bike models or brands prioritize speed above other performance indices. A few others focus on the torque and overall acceleration of the bike rather than speed.

So, although two brands may have the same engine size displacement, they may not have the same power and torque. This, in turn, impacts the speed of the bike.

2. Weight of the bike and rider

Man riding his red dirt bike in the trail

It is common logic that heavier objects tend to move slower. In the case of the 450cc dirt bike, this weight can be the weight of the rider or even its own weight.

The weight the bike has to accelerate against puts a strain on the bike’s engine and transmission. As a consequence, heavier riders will find it more difficult to reach a 450cc dirt bike top speed.

3. Type of terrain and track

As is characteristic of motocross racing, some obstacles must be overcome. From taking turns and riding through rough terrain, the motocross track can be treacherous. It is a great risk to the rider to adopt an aggressive riding style on such tracks.

Following that, many experienced riders cannot reach top speed on such terrains. On rough terrain, the speed is low. But on smooth and flat surfaces, the bike can reach higher if not top speed.

The Average Speed Range of 450cc Dirt Bikes

The average speed range for a 450cc dirt bike is 97-123 mph (156-198 km/h). As highlighted earlier, the top speed of a 450cc dirt bike is highly dependent on the brand and/or model of the bike.

Thus, while the KTM 450 SX-F can reach a top speed of 123 mph (198 km/h), the Kawasaki KX450’s top speed is 89 mph (143 km/h). Some bike’s top speeds include:

Comparison with other Motorcycle Classes

Different colors of dirt bikes line up

A clear difference in motorcycle classes is the engine size displacement. But this is not where all the difference lies. The handling of these bike classes differs. There is also a difference in how nimble they are as well as their top-speed capabilities. 

Let’s look at some of these classes in comparison to the 450cc dirt bike.

125cc Dirt Bikes

The 125cc dirt bikes can be used for both motocross racing and off-road trail riding. But the greatest comfort of the 125cc dirt bike class is how relatively lightweight it is. This especially when compared to the 450cc. This makes acceleration faster. 

These bikes are better suited for young riders as the top speed they can muster is 75 mph (121 km/h). This is a speed not too high for the young riders nor too slow to bore them. Unlike the 450cc dirt bike, they cannot be used in professional motocross racing.

250cc Dirt Bikes

250cc dirt bikes combine the nimbleness of the 125cc with the 450 dirt bike top speed. Thus, intermediate-skilled riders can handle with ease the power generated by these bikes. The 250cc dirt bikes top speed within the range of 55-75 mph (88-120 km/h).

Top 450cc Dirt Bike Contenders

Overview of some 2023 Models of Motocross and Enduro Bikes

There are lots of 450cc bikes with varying performance and top speeds. Here are a few motocross and enduro bikes of the 450cc class:

Motocross KTM 450 SX-F

Isolated image of KTM 450 SX F dirt bike in beige background

The KTM 450 SX-F is a high-performance bike with a powerful 449cc engine. This engine has a 54.3HP at 9,400 rpm horsepower. The KTM 450 SX-F is a popular choice among professional motocross riders. 

‘When a factory builds a bike, you lose a little somewhere else. “That wasn’t the case…the suspension started working better…they brought to the table a better bike.”

Ryan Dungey, Motocross Champion

Attaining a top speed of 123 mph (198 km/h), the KTM 450 SX-F is the fastest dirt bike in the world. 

Full-Size MX Kawasaki KX450 

The Kawasaki KX450 is one of the big Japanese four. Like the others, its reputation for durability and reliability precedes it. Like its KTM rival, it has won a lot of Motocross championships. 

Yamaha YZ450F

Yamaha outdid itself with the improved ergonomics of this bike. Its peak torque of 32.7 lb-ft generates a remarkable 54.4 hp. This gives the bike enough speed to rank among the speed toppers in this class. 

Motocross Husqvarna FC 450

The Husqvarna might be a lesser-known name compared to the KTM. But what it lacks in public exposure, it gains in speed and track cred. This bike can reach an impressive top speed of 107 mph (172 km/h). 

Motocross GasGas MC 450F

Unmistakably, the GasGas MC 450F is a great addition to the 450cc dirt bike class. The WP XACT suspension system gives it great stability to grind at a top speed of 120 mph (193 km/h).

Comparison Table of the Top Dirt Bike Contenders in the 450cc Class

KTM 450 SX-FKawasaki KX450Yamaha YZ450FGasGas MC450FHusqvarna FC 450
Engine 449.9cc,
Power 54.3 Hp
33.8 Lb.-Ft.  
51.9 Hp
32.6 Lb.-Ft. 
54.4 Hp
32.7 Lb.-Ft. 
53.0 Hp
33.9 Lb.-Ft.
53.7 Hp
33.2 Lb.-Ft.
Weight 228 Lbs 233.2 Lbs 240 Lbs 220 Lbs 228.62 Lbs
Dimensions N/A86.0 In. x
32.3 In. x
49. 8 In.
86.0 In. x
32 In. x
50 In.
85.8 In. x
32.5 In. x
50.2 In.
Top speed 123 Mph 96 Mph 90 Mph 120 Mph  107 Mph

Analysis of the Top Contender Dirt Bikes

From the table, you can see that the KTM 450 SX-F can reach a top speed of 123 mph (198 km/h). While the Kawasaki KX450’s top speed is 89 mph (143 km/h). Among these top contenders, the bike with the least top speed is the Yamaha YZ450F.

Pros and Cons

KTM 450 SX-FSturdy frame 
Superior suspension 
High speed 
Stiff ride experience 
Slim cockpit 
Kawasaki KX450 Swift throttle response
Strong brakes
Great power 
Not as fast as others in the class
High maintenance cost
Yamaha YZ450FPremium suspension 
Well balanced 
Electric starter
Not fuel-efficient 
Too heavy
GasGas MC450FHigh-quality components
Reliable and durable bike
Limited availability of parts
Maintenance can be expensive
Husqvarna FC 450Predictable handling
Friendly control
Intuitive response
Dealers are not widespread 
Can feel heavy to some riders

Bottom Line

Factors including riding skills, the weight of the rider and the type of terrain the bike is being ridden on can affect speed. They add up to affect the power and performance of a 450cc dirt bike. But, the 450cc bikes are one of the fastest in the dirt bike world. 


Is a 450cc faster than 250cc?

Yes, a 450cc dirt bike is faster than a 250cc dirt bike. This is mostly due to larger engine size and higher power output. This translates to a higher top speed.

How Fast is 450cc in km/h?

A 450cc has a speed range of 156-198 km/h.