How Fast Does A 100cc Dirt Bike Go?

Racing down a dirt track on a powerful 100cc dirt bike is an adrenaline rush like no other. But what is the top speed that these bikes can achieve?

How fast does a 100cc dirt bike go?

Many factors influence how fast a dirt bike can travel, including the weight of the rider, the type of terrain, and the engine size.

In this blog post, we’ll take a look at how fast is 100cc dirt bike exactly.

100cc Dirt Bikes

First, let’s look at some of the basic concepts of 100cc dirt bikes.

Rider’s Age

Children aged between nine and ten years old can ride 100cc offroad motorcycles, and even some adults, particularly those who are medium height (up to 162 centimeters) and weigh less than 160 kilograms.

Seat Height

Setting the right seat height is also important to determine how fast your 100cc dirt bike will go. The seat height should be set according to your age and height.

For example, if your height is 162 cm, you need to set a seat height of 33-36″.

Horsepower and Transmission

A 100cc motorcycle is very fast because of its engine strength. So you can expect enough power, a horsepower strength of 50PH or greater.

You can achieve a very high maximum speed with a 100cc dirt bike for adults.

Engine Stroke

The 100cc dirt bike comes in four-stroke engine and two-stroke engine models. The higher the engine stroke, the higher will be the average speed miles per hour of the dirt bike.


Depending upon the type of engine, 2-stroke or 4-stroke, the dirt bike can achieve an average speed of 45-55 miles per hour (70 – 90 kilometers per hour).

Experienced riders can reach speeds up to 70 mph (112 mph) or more on their dirt bikes.

Kids can easily ride at an average speed of 25-40 miles per hour (40 – 65 kilometers per hour).


If you want to increase the speed of your dirt bike, then you must reduce the weight. This means that you have to remove unnecessary parts from your dirt bike.

Frame Size

Most dirt bikes come in three sizes: small, medium, and large.

Small dirt bikes usually measure around 55 inches long, while medium-sized ones range from 60 to 65 inches. Large dirt bikes are longer than 75 inches.


The wheelbase refers to the distance between the front and rear wheels.

If you want to increase the acceleration rate of your dirt bike, you should make sure that the wheelbase is as short as possible.



Tires play a major role in determining how fast your dirt bike goes. Tires with larger diameter tires offer better traction and grip.

However, smaller tires provide better handling and maneuverability.


You need brakes to slow down your dirt bike when you’re going downhill. The brake system is usually made of steel or aluminum alloy.


The motor is the heart of any dirt bike. It provides the power needed to propel the vehicle forward.

Motor types include single-cylinder, twin cylinder, and V4 engines.

Exhaust System

Your exhaust system plays a significant role in improving the performance of your dirt bike. Exhaust systems are made of stainless steel, titanium, or other materials.

Fuel Tank

Your fuel tank stores the liquid fuel used by the engine. Fuel tanks are usually made of plastic, fiberglass, or metal.


Handlebars are the steering device used to control the direction of movement of your dirt bike. Handlebar styles vary depending on the type of riding terrain.


Rims are the part of the tire that touches the ground. They help keep the tire inflated and prevent the tire from slipping off the rim.

Rim styles vary based on the size of the tire.


Suspension helps improve the handling of your dirt bike.

There are several suspension designs available, including coil springs, air shocks, gas shocks, and hydraulic shock absorbers.

Front Fork

A fork is the frame part that holds the front wheel. Front forks come in different shapes and sizes.

Now that we’ve covered all the basics about 100cc dirt bikes, it’s time to get down to business. We’ll now discuss how fast is 100cc dirt bike.

How Fast is the 100cc Dirt Bike 2-Stroke Model?

A 100cc dirtbike can reach speeds up to 65 mph (or even faster) depending on its engine power output, rider’s body size, and riding skill.

How Fast is the 100cc Dirt Bike 4-Stroke Model?

You can get a slightly lower top speed of 55 mph for a 4-stroke 100 cc dirt bike.

Let’s now look at the top speeds of dirt bikes with different engine capacities.

Engine capacity (CC)Top Speed (miles per hour)
50cc dirt bike25 – 35 mph
65cc dirt bike30 – 45 mph
70cc dirt bikes40 – 50 mph
85cc dirt bikes45 – 55 mph
110cc dirt bike50 – 65 mph
125cc dirt bike50 – 75 mph
150cc dirt bike55 – 80 mph
200cc dirt bike65 – 85 mph
250cc dirt bike70 – 85 mph
400cc dirt bike75 – 85 mph
450cc dirt bike80 – 90 mph
500cc dirt bike85 – 95 mph

How to Make a 100cc Dirt Bike Go Faster?

Here are some tips to make your dirt bike go faster:

Choose a Lightweight Bike

If you want to accelerate quickly, choose a lightweight dirt bike. Lightweight bikes weigh less than 150 pounds.

This will allow you to accelerate more easily.

Use High-Performance Tires

High-performance tires have large tread patterns and low rolling resistance. These tires give you better traction and grip.

Adjust the Suspension Settings

Adjusting the suspension settings can improve the handling of your bike. You can adjust the suspension settings using levers located near the handlebars.

Increase the Engine Power

Increasing the engine power can increase the acceleration of your dirt bike. To do this, you can use a higher-capacity carburetor.

Change the Oil Regularly

Changing the oil regularly ensures that your dirt bike runs smoothly. Oil changes should be done every 3,000 miles.

Avoid Overloading Your Dirt Bike

Overloading your dirt bike can cause unnecessary damage to the components. Overloading also reduces the life span of your bike.

Avoid Sharp Turns

Sharp Turns

Sharp turns can cause reduce your speed and also cause your dirt bike to lose balance. Sharp turns also require extra effort to maintain stability.

Make Use of Better Gas Types

In a dirt bike, higher quality gasoline may be used to obtain an acceptable result. By using better quality gas, you can make your dirt bike go faster.

You can use either 87-octane or 92-octane fuel in your motocross bike, depending on the type of bike you have. For a 4-stroke engine, the 82-octane fuel will work just fine.

However, for a 2-stroke engine, you should go for ethanol-free fuels with higher octanes such as 92 and 93 because lower octanes have a tendency to detonate.

Keep Your Dirt Bike Clean

Keeping your dirt bike clean prevents rust and corrosion. Clean dirt bikes are easier to ride and last longer.

Don’t Forget to Check the Chain

Chain tension affects the performance of your dirt bike. If the chain is too tight or loose, then your bike may not run properly.


100cc dirt bikes are fun to ride because they offer great maneuverability. They’re easy to control and can be ridden by beginners as well as experienced riders.

However, if you want to go faster, you need to invest in a powerful engine. In addition, you must keep your dirt bike clean and free from rust and corrosion.

The rider experience, too, will play a major part in how fast your 100cc can go. Experienced, professional riders will be able to ride at high speeds compared to a novice riders.

We hope these tips help you learn how to make a 100cc go faster. We wish you good luck!

Thomas Kersten

Hi, I am a passionate biker, and I have been riding for more than ten years and share my biking tips and tricks with the world. I've tested more than 300 bikes.

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.