How Fast Is a 125cc Dirt Bike? Find Out Its Maximum Speed 

How Fast Is a 125cc Dirt Bike? Find Out Its Maximum Speed 

A 125cc dirt bike is perfect for new riders who are starting to discover a thrilling hobby. It isn’t the fastest, but that does not mean that it has inferior performance. The top speed can vary from one model to another, as well as other factors, such as the environment and skills of the rider. 

How fast is a 125cc dirt bike? If you are asking this question, we got you! This guide also talks about the factors that affect its speed, as well as the things that you can do to make it faster! 

How Fast Is a 125cc Dirt Bike? 

man riding a motocross bike

The average speed of a 125cc dirt bike ranges from 55 to 65 miles per hour. While some people try to put their dirt bikes to go at 100 miles per hour, this is not advisable because the bike’s engine is small and cannot handle high speeds for extended periods of time. 

125cc is a small engine, and hence, its power is not comparable to those that you will find in its faster competitors. 

While it is slow, there are several performance upgrades and riding techniques that will let you make it faster. 

Different Factors that Affect the Speed of a 125cc Dirt Bike 

A 125cc dirt bike can be slower or faster depending on different factors, including the following: 

  • 2-Stroke vs 4-Stroke 

2 stroke vs 4 stroke hp difference

When choosing a dirt bike, one of the most important considerations is the engine. It directly impacts the overall performance, including speed. 

A 2-stroke engine has two functions–compression and combustion. It is hard and fast-hitting, so it is explosive on the track. While it is more common in older dirt bikes, if speed is your priority, then this can be a better option as it can reach a maximum speed of 60 mph. 

On the other hand, a 4-stroke engine is slightly slower, registering an approximate speed of 50 mph. The tractor and weight of the engine contribute to it being sluggish. 

  • Load 

Similar to cars or other vehicles, the load of a 125cc dirt bike also greatly impacts its speed. Depending on the model that you choose, the maximum load can range from 200 to 250 pounds. 

The load depends not only on the weight of the rider but also on the cargo and the components of the dirt bike. Many will have various performance upgrades that can add to the weight of the bike, slowing it down. 

  • Environmental Conditions 

dirt bike riders for a race

External factors can also slow down a 125cc dirt bike. For instance, its speed will vary greatly depending on the terrain. The muddier the terrain gets, the slower the dirt bike will be. The same thing also happens when there are many twists and turns that you have to be mindful of. 

The wind is another environmental factor that can make your dirt bike slower. The windier it is, the more drag there will be, making it more difficult for the bike to reach its top speed.

  • Dirt Bike’s Customizations 

It is fun customizing a dirt bike. You can experiment with different parts and accessories to enhance its aesthetic and performance. Nonetheless, you might be unaware, but some of these customizations are adding a burden of weight, which affects the speed of your 125cc dirt bike. 

For instance, changing into bigger and bulkier tires may make your bike look like a beast, but it can compromise speed as it constitutes added weight. The same thing is true when you are upgrading seats. 

  • Driver’s Experience 

At the end of the day, even if you have the best dirt bike with a top-notch engine, it is hard to reach the top speed when you lack experience. If you are new to dirt biking, you are probably still learning the techniques. Not to mention, some may be nervous to rev up the throttle and reach the maximum speed. 

Tips and Tricks to Make Your 125cc Dirt Bike Faster 

A 125cc bike is basic and often targets new riders, so we do not expect much when it comes to its speed. Nonetheless, you can do some things to maximize its performance, including the following: 

  • Train Your Body 

The dirt bike alone is not enough to go full blast on a track. Your physical condition is equally important. With this, train your body and be ready for the demands of the ride. The more conditioned you are, the easier it is to reach the dirt bike’s top speed. 

Among others, one of the most important things to learn is the proper stance. This will let you find the perfect balance during your ride. This way, you are not only properly distributing your weight on the bike, but you are also improving handling. 

Getting in shape is important. This will give you a stronger mind and body. As a result, you can confront the challenges on the track and think straight to unleash your inner beast on a dirt bike. 

  • Swap the Exhaust 

Even if you are physically and mentally ready for the ride, your bike will not be at its fastest if it has inferior components. With this, you might want to consider a few performance upgrades, and one of the most promising is the exhaust. 

The muffler is a crucial component of the exhaust system. Consider adding a pipe in a two-stroke engine or a slip-on in a four-stroke engine for incremental speed improvements. This muffler upgrade can take only about 15 minutes, so it is an easy solution even for a newbie. 

  • Adjust the Suspension 

Purchasing an aftermarket suspension for a 125cc dirt bike might initially seem expensive. However, once you know how it can improve speed, you will realize that it is worth it. As a bonus, it will also make your bike more comfortable as it is effective in shock absorption. 

With an enhanced suspension, control is improved, even in challenging terrains. This will let you handle the bike better, positively affecting its speed. It also makes the dirt bike feel more balanced. 

  • Keep it Clean 

Even without spending a lot on aftermarket upgrades, you can make fastest dirt bike ever. This is possible through regular cleaning. Over time, mud and dirt will accumulate on the tires and other parts of the bike, which can slow it down. 

Failure to maintain the dirt bike would make its components wear out faster. In turn, this compromises overall performance, including speed. Aside from cleaning, consider replacing the parts that are no longer functioning as expected. 

Lubrication is also crucial in keeping your dirt bike clean. This will make sure that the moving parts are working smoothly. Otherwise, the bike could become sluggish and unresponsive. 

Essential Safety Considerations 

More than speed, safety is important when you are riding a 125cc dirt bike. Especially since most people who use such bikes are young and inexperienced riders, take note of these safety tips: 

  • Follow the Speed Limit 

When you are riding on muddy tracks, there is probably no speed limit, so you can go as fast as you want, depending on what the bike is capable of. However, if you are using the bike on the road, make sure to follow the speed limit that the local authorities impose. 

  • Know the Environment 

Being familiar with the environment is another important safety tip. Scan the area before you ride. Know the type of surface where you will be riding. Look at the map or see the twists and turns. This way, you can anticipate the challenges that can confront you during your ride. More so, it will help in your mental preparation. 

  • Inspect Your Dirt Bike 

Take the time to thoroughly inspect the dirt bike before every ride. From the engine to the seat, make sure that everything is in good condition. If there is any problem, fix it immediately. Otherwise, do not go on with the ride, especially if you are aware that the issues will make your ride unsafe. 

  • Wear the Right Gear 

Gear up for your safety. Choose something lightweight so that it won’t be a burden on your speed. At the same time, make sure that it is up to the highest standards to keep you safe and sound throughout the ride. From helmets to knee pads, invest in accessories that will provide you with peace of mind. 

  • Gauge Your Skills 

Do not go beyond the speed that you can realistically handle. You probably know yourself, so set the limit when it comes to how far you can go. As a beginner, start slow and gradually progress into a faster ride as you master the techniques. 

Final Thoughts

As noted above, a 125cc bike can go as fast as 55 to 60 mph, but the specifics will depend on several factors. For instance, a two-stroke engine is faster than a four-stroke engine. The experience of the rider, environmental conditions, and upgrades on the motorcycle are also crucial factors that impact the speed. 

While a 125cc dirt bike isn’t meant to race like a beast, there are some things that you can do to make it faster. For instance, you can try performance upgrades, such as swapping the exhaust and adjusting the suspension. You can also work on your techniques and skills, including physical and mental conditioning, to improve speed.

joshua mattie

Joshua D. Mattie

My motorbike addiction began with 50cc at 5 years old. I rode motocross as a teenager & into my 20's when I worked as a mechanic. This helped me to see the light—sportbikes & cruisers became a passion. Now I'm building BikersRights to be the #1 resource for everything on 2 wheels!