How Fast Is a 50cc Dirt Bike for Kids?

How Fast Is a 50cc Dirt Bike for Kids?

The 50cc dirt bikes are the smallest in the market, making them suitable for introducing young kids to motorcycles. However, as a parent, you might be wondering how fast a 50cc dirt bike goes and if the speed is safe for kids.

Generally, 50cc dirt bikes have variable speed limits depending on the brand and engine design of the model. Additionally, most kids can enjoy riding their bikes without pushing the full throttle to maintain their speed at a comfortable level. 

So, how fast does a 50cc dirt bike go? Let’s find out… 

How Fast Does a 50cc Dirt Bike Go?

There are three types of 50cc dirt bikes available: trail, motocross, and electric bikes. 

The Razor Dirt Rocket SX500

The Razor Dirt Rocket SX500 electric dirt bike is a great entry-level option for kids as it has a significantly low speed of 15mph. On the upside, it is street-legal and is safe to ride around the neighborhood. However, electric bikes are too slow for anything exciting such as racing and trail riding, and your child may outgrow it pretty quickly. 

The 50cc trail dirt bikes, such as the Honda CRF50F and Yamaha TTR50E, are popular choices for beginner riders as they provide adjustable speed limits that help kids get acquainted with handling dirt bikes safely. 

Trail dirt bikes have varying maximum speed limits between 25 to 40 miles per hour, depending on the brand and size of the bike. 

Mini trail bikes with a low seat height, such as the Yamaha PW50, have a speed range between 20 to 28 mph, suitable for young kids between 4 to 6 years old. 

On the other end, the Honda CRF50F features a 3-inch higher seat and has a significantly higher maximum speed of 35 mph for older 5- to 7-year-old kids. 

Motocross bikes such as the KTM SX50 Mini are ideal for kids with riding experience because of their higher top speed of 45 mph and a higher seat height suitable for bigger kids. However, it also has better handling due to its lightweight construction and suspension system, making it an excellent choice for introducing kids to motocross racing. 

Factors Affecting Dirt Bike Speed

Yamaha PW50 dirt bike

While engine capacity is the main determining factor of speed on a motorcycle, other variables can affect how fast your 50cc dirt bike can go. One factor is the weight of the dirt bike. Lightweight dirt bikes, such as the Yamaha PW50, are quicker and are easier to handle, unlike a heavier model. 

Engine Type

Dirt bike specifications such as the engine type and modifications on the sprocket gearing can also influence the motorcycle performance and speed. 

The 2-stroke engines are typically much faster and lighter than 4-strokes, making them ideal for motocross racing dirt bikes. On the other hand, a 4-stroke dirt bike has a broader power band which requires less switching gears on a motorcycle and is easier for new riders to handle. 

Gear Ratio 

Another factor affecting speed is gear ratio. You can modify the sprocket gearing to improve the performance and average speed of the dirt bike, and you can achieve this by changing the gear ratio of the bike. 

dirt bike engine with front sprocket and chain

The objective is to increase the top speed and gain a competitive advantage while racing without compromising the low-end torque acceleration. Gear ratio generally refers to how the size of the front and rear sprockets relate to each other. 

For instance, you may replace the dirt bike's front or rear stock sprockets with a larger or smaller tooth sprocket to gear up or down to achieve the speed you want.

A smaller rear sprocket will improve the top speed, while a larger rear sprocket will improve the acceleration but lower the maximum speed.

Can You Limit the Speed on a 50cc Dirt Bike?

If you are concerned about how fast the dirt bike you get for your kid, you could opt for models with a low full-throttle speed, such as the Yamaha PW50. 

But if the kid is a little bigger and adventurous, you could get a dirt bike with a throttle limiter and kill switch for safety. 

Let's look at how each of these features works below.

Throttle Limiter

A throttle limiter feature restricts the amount of power over a specific speed by shortening the throttle turning radius. The limiter helps new riders gain experience and confidence on their dirt bikes while maintaining a safe speed. 

It also helps provide a more linear power delivery in 2-stroke engine dirt bikes, making it easy for the kid to accelerate smoothly on bumpy trails. Most 50cc trail bikes come with a throttle limiter, while some motocross bikes have it as an accessory. 

The throttle limiter is located on the throttle grip of your mini dirt bike. To adjust the speed limit, you begin by opening the two bolts on the limiter cover and removing the cover of the throttle grip. 

You will then see three smaller screw holes with a screw on the first hole on it. You will want to move to the last hole to reduce the turning angle of the throttle and lower the maximum speed limit. 

Once adjusted, return the cover of the throttle grip by screwing back the two bolts firmly. You'll notice that the throttle now makes a half turn instead of going wide open like it did before. 

It is a notably simple way to regulate how fast your kid rides their dirt bike, unlike trying to supervise them to maintain low gear. Plus, you can just as easily adjust it back when they gain riding experience. 

Kill Switch

The kill switch is not a common feature in 50cc dirt bikes like the throttle limiter. However, you can find them on large-capacity dirt bikes, and you can install one on your kid's dirt bike as an added safety feature. 

The kill switch helps to shut down the motorbike engine the quickest way possible during an emergency. It works the same way as the ignition key but is more accessible due to its location on the dirt bike's handlebars. 

On the other hand, forgetting to turn off the ignition when the dirt bike is parked or turning on the kill switch with the ignition may result in a flat battery. The advantage of a kill switch on your kid's dirt bike is that it provides an emergency stop option when they lose control of the bike. 

When the rider activates the kill switch while the motorcycle is in motion, it cuts the power to the engine, and the dirt bike slowly loses momentum until it comes to a stop. 

How Can I Make My Dirt Bike Go Faster?

While adjusting the gear ratio of your kid's dirt bike is the most effective way of making it go faster, regular maintenance can also improve performance. 

Here are some actions you can perform on your kid's dirt bike, but keep in mind that any significant modifications may void the warranty. 

  • Carbon residue often builds up inside the exhaust pipe and can inhibit airflow into the engine, and regular cleaning can restore optimum performance. Additionally, you can modify the air intake tank by drilling holes on it to increase the airflow and engine combustion.
  • Cleaning your spark plugs or replacing faulty ones will improve the acceleration of your motorbike. However, you can also replace the stock spark plugs on the dirt bike with V-shaped spark plugs that spark a little faster and more reliably.
  • Another option is to switch the motorcycle oil with synthetic oil as it has better low and high viscosity and low-temperature performance than regular oil. Therefore, it gives you improved horsepower and torque and better fuel economy. 

Are 50cc Dirt Bikes Safe for Kids?

There is a common misconception that ATVs are safer for kids because they are perceived to be more stable, which gives children the confidence to ride faster. But, they are also heavier than dirt bikes, and an ATV accident is 50% more likely to be fatal than dirt bikes.

On the other hand, riding a 50cc dirt bike is also risky for young kids because they get exposed to severe injuries when they lose control and tumble. But like any sport, it is important to maintain safety precautions to minimize risks.

One of the best ways to keep your kids safe is to ensure that they always wear protective gear every time they ride. It is also necessary to emphasize to them the importance of wearing gear and staying alert while riding to avoid accidents. 

It is also essential that the dirt bike suits your child's height and riding ability so that they are confident in handling it.

Final Thoughts

To address your concern about how fast a 50cc dirt bike goes, the average speed range of a 50cc dirt bike is between 25mph to 40mph, which some parents feel may be too fast for their young ones. However, we have provided some ideas on how you can reduce the speed limit to help your kid handle the bike easily until they gain more experience. 

If you are still apprehensive, you can start your young rider on an electric bike because they are much slower at 15 miles per hour and safer for children than the gas-powered models. Additionally, when you provide your kids with safety gear, you can ensure that they ride safely, and you minimize the severity of injuries should they have an accident.

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!