How to Size a Dirt Bike for Kids: Top Tips to Learn Before Buying


A dirt bike is the ultimate riding machine for a lot of kids. Imagine a bicycle on steroids, and you’ve got a dirt bike. It’s heavier, faster, louder, and, of course, more expensive. For their safety and maximum enjoyment, it’s essential that you get the right size dirt bike for your kid.

Choosing the right size dirt bike for kids involves determining the seat height that fits their body, as well as understanding how engine size in cc’s affects the possible speeds the bike can reach. It’s best to start with a less powerful bike to gain experience before moving to faster models.

Not too sure about this whole dirt bike thing for your youngster? You may have many questions, starting with how old a child should be to get a dirt bike or how to pick the appropriate size bike. We’re here to guide you through these questions and more, so pop that kickstand and read on.

Is a Dirt Bike Appropriate for Kids?

Saying the words “dirt bikes” and “kids” in the same breath generates a lot of discussion among parents. There’s the “over my dead body” crowd and, at the opposite end of the spectrum, the “let kids be kids” group, plus everything in between.

We’re not going to debate the issue or try to convince you one way or the other. In fact, I’d bet that you’re here because you’ve already decided to get one and now you need some info. Am I right? Well good news, because info is what we’ve got.

are dirt bikes appropriate for kids yinzbuy e1627020454355

Deciding to let your kid ride a dirt bike is a personal decision completely dependent on the comfort level you have with the idea and your child’s interest, maturity level, and physical ability.

As with most sports and activities that involve speed, dirt bikes do present an element of risk to the rider. Is it enough to keep you from letting your child get a bike? Probably not if it’s something they really want to do. I know a little danger never steered me away from anything as a kid.

How to Choose the Right Dirt Bike for Your Kid

Now that you’ve decided to invest in a dirt bike for your kid, keep these thoughts in mind:

  • Choose the right size bike for your child (more on this later)
  • Select and insist that your child wear the proper gear. NO EXCEPTIONS.
  • Provide close supervision when your kid rides, especially at younger ages.
  • Never force a child to ride if they don’t want to.

Dirt bikes are essentially all the same: two wheels, a seat, and handlebars for steering. Even so, within the basic dirt bike design, there are three distinguishing factors you should look at when shopping for a bike:

  • Engine size is the cylinder volume in the engine. You’ll see it listed as cc’s, as in 140cc.  
  • Safety features include reliability, training wheels if needed, kill switch, and automatic transmission
  • Top speed can be an indicator of the bike’s power. Some models have an adjustable throttle to limit max speed.  

The difference between bike types is what makes them go. Electric bikes are powered by rechargeable batteries, while gas-powered bikes run on the kind of gas used in cars.

Gas-Powered Bikes

Gas engine dirt bikes are fun to ride. They typically offer more power and faster top speeds, as well as front and rear disc brakes. Many models come with a speed throttle that lets you set the top speed and an automatic transmission that makes riding much easier for beginners. Riding time is limited only by the gas tank level.

You’ll need to do routine maintenance on a gas-powered bike, just like you would on your car. Oil and air filter changes keep the bike running smoothly. You’ll also need to keep a gas can on hand to resupply fuel as needed.

Electric-Powered Bikes

Electric bikes are battery-powered, and you can find them in a variety of wattages and battery sizes. With an electric bike, you have less maintenance, like no oil changes or air filter cleanings. They are quieter and offer an eco-friendly alternative to the traditional gas-powered dirt bike.

Riding time is constrained by how long the battery stays charged.

At What Age Should a Kid Get a Dirt Bike?

There is no hard and fast rule about when a kid can, or should, get a dirt bike. The most important thing is to put them on an age-appropriate model that suits their size and skill. With the proper safety precautions in place and a little practice, your kid will be excited to ride, and you’ll worry a whole lot less.

young child riding motocross dirt bike with pink protective gear

A few kids may be capable of riding at the age of two or two and a half if they’re physically big enough to sit on the bike and touch the ground. Whether they should or not is a matter of personal opinion and sometimes heated debate.

However, a lot of kids begin riding dirt bikes when they are three to four years of age.

How Will I Know If My Child Is Ready for a Dirt Bike?

If your child has expressed interest in riding a dirt bike, there are a few key factors to watch for before turning them loose on a bike:

  • Can they sit on the seat and still touch the ground?
  • Do they have the hand strength to grip the handlebars tightly enough?
  • Are they able to manipulate the throttle and brake to speed up and slow down?
  • Can they steer and stay on course?
  • Are they able to stay upright on the bike as it hits bumps?
  • Is riding a dirt bike something they really, really want to do?

razor mx350 dirt bike ages 4 to 6 electric motocross

Putting a two to four year old on a dirt bike is similar to giving a six-month-old swimming lessons in a pool. At such a young age, they may not have perfect form or be ready for the dirt bike olympics, but they can begin to learn the skills needed to ride safely with parental oversight and guidance. I know I fell off my bike more times than I can count. It’s learning and getting back up that makes you improve!

It’s best to start a preschool age child out on a small electric, 6V dirt bike outfitted with training wheels. Be sure to adjust the speed to slower than five mph.

By the time kids reach the ages of five or six, most can enjoy short rides on more advanced bikes with 50 cc engines. Some kids may still use training wheels, but many have mastered the balancing skills needed to keep the bike vertical.

What Size Dirt Bike Does a Kid Need?

When you’re talking about the size of a dirt bike for kids, you really have to think of it in two different ways. Both are important factors when it comes to choosing the age-appropriate bike for your child.

  • The size of the bike is measured by the height of the seat from the ground.
  • The size of the engine is measured in cubic centimeters (cc). Higher cc’s equals a more powerful engine and faster bike.

The size bike your child needs depends on their physical size, primarily height; however, weight is also a consideration.

Remember every child is different. You are the expert on your child and what they can handle. The following chart offers a general guideline for choosing the right size bike for your child:

How to Find the Right Size Dirt Bike for Your Child

Age Child’s Height Seat Height Engine Size
4 and under 34” – 41” 86 – 104 cm 18” – 23” 46 – 58 cm 6v electric
5 – 7 years 42” – 48” 107 – 122 cm 23” – 25” 58 – 64 cm 50/70 cc gas
8 – 9 years 50” – 55” 127 – 140 cm 24” – 28” 61 – 71 cm 70/110 cc gas
10 – 12 years 55” – 59” 140 – 150 cm 26” – 31” 66 – 79 cm 110/125 cc gas
13 years and up 5’2” 157 cm 31” – 35” 79 – 89 cm 125 cc-140 cc gas
5’4” 163 cm 33” – 36” 84 – 91 cm
5’6” 168 cm 34” – 37” 86 – 94 cm
5’8” 173 cm 34” – 38” 86 – 97 cm
5’10” 178 cm 35” – 39” 89 – 99 cm
How to pick the right size dirt bike for your child

Seat Height

Every kid is built differently, with varying combinations of leg and arm length, as well as weight, to consider when choosing a bike. I have long legs, and believe me it’s uncomfortable riding a bike designed for someone with short legs.

To pick the right height dirt bike, one popular option is to visit a motorcycle dealership and test them out. If you don’t have a local dealership, try using your kid’s bicycle for measurements. The handlebar setup will differ, but the overall height of the seat is similar. Just make sure to measure and compare the tire size, as a difference there will affect the frame and thus the seat height.

child sitting on dirt bike

When you’re ready to take measurements, have your child do the following:

  • Sit on the bike in a relaxed, comfortable position.
  • The balls of the feet should touch the ground; heels should be in the air. (Flat-footed means the bike is too short; tippy toes means the bike is too tall.) 
  • Be sure all the child’s weight is on the bike and not on their legs.
  • Extend the arms and hands to reach the controls. The distance should feel comfortable without having to strain. Otherwise, an accident is likely to occur.

If the bike seat is adjustable, consider going with a slightly higher bike to allow for your child’s inevitable growth. Start with the seat at its lowest position and work through the different height settings as needed.

When measuring isn’t possible, follow the manufacturer’s recommendations for rider age and weight. Adjustable seats and handlebars offer some flexibility in getting the right fit. For online shoppers, try picking a bike that can be returned. Return windows may be limited along with possible restocking fees, but it’s better than being stuck with a bike your kid can’t use.

Engine Size

Engine size correlates to speed but isn’t necessarily related to the height of the bike. The more cc’s the bike has, the stronger the engine. For the youngest kids, look for a 50 cc dirt bike with top speeds of less than 10 mph; around 3 mph is ideal. In fact, the 50 cc engine dirt bikes are a good choice for any beginner.

As children get older and develop more riding skill and control, they’ll want the thrill that comes with more speed. They can graduate to a dirt bike for kids with bigger engines, like 80-110 cc models.

Using Speed to Determine Size

The need for speed. That’s one of the best things about a dirt bike—the ability to rev it up and ride faster than you can on a pedal bike. 

Dirt bikes are built for speed, but top speeds vary based on the size of the engine and whether the bike is powered by a gas or electric motor. For younger kids, top speeds can be lowered with throttle limits.

To help you choose the correct size bike for your kid, you need to understand how engine size is measured and how that translates to actual speed.

What Does CC Mean?

When you see a bike advertised as 50cc or 140cc, you may wonder what that means, especially if you’re a newbie to the world of dirt bikes and engines in general. It’s an important thing to know, though, because “cc” is an indicator of engine size and power.

The term “cc” stands for cubic centimeters and measures the engine capacity, or displacement. With an internal combustion engine, it represents the engine’s ability to push an air and fuel mixture through the engine. puts it like this:

“The larger the volume of the cylinders (or the higher the CC), the more air and fuel the engine is able to suck in at once, and the more power the engine will be able to generate.”

You’ll also find terms like two-stroke” or “four-stroke engines”. Basically, this designation indicates how many times a piston moves up and down during the combustion cycle. 

  • Two-stroke engine: The piston moves up and down one time (two strokes total) as the combustion cycle occurs. They run at a higher RPM (revolutions per minute), requiring more gear shifts and making them a powerful and intense ride. They are noisier and emit a high-pitched buzzing sound when running. Overall, two-stroke engines don’t last as long as four-strokes.
  • Four-stroke engine: The piston moves up and down twice during the combustion cycle, making four strokes total. The four-stroke engine runs at lower RPMs, but with a higher torque. It runs more quietly than the two-stroke and tends to be more durable and last longer.

So, what does this actually mean when it comes to choosing the best size dirt bike for kids?

How CC Relates To Speed

According to It Still Runs, you cannot convert directly from cubic centimeters (cc) to miles per hour (MPH). However, there is definitely a connection between the two.

This CC speed chart offers a sampling of engine sizes and the range of top speeds to expect. Speeds will vary depending on several factors beyond just engine size, such as:

  • Road or track conditions
  • Weight of the rider
  • Throttle limits
  • Number of strokes per combustion cycle
Engine Size Top Speed Range
50cc 4-stroke Up to 20 mph
50cc 2-stroke 25 – 40 mph
65cc 2-stroke 50+ mph
70cc 4-stroke 30 – 35 mph
110cc 4-stroke 40+ mph
125cc 4 stroke 50 – 55 mph
125cc 2-stroke 70 – 75 mph
How CC relates to speed

Other Considerations for Dirt Bikes

Beyond size, here are a few other factors you should consider before purchasing a dirt bike for kids:

Are Dirt Bikes Expensive to Maintain?

Just like with cars, there is always some routine maintenance that has to be done to keep them running smoothly. Dirt bikes are no exception. Gas-powered bikes definitely need constant attention to keep the small engines purring.

child working on dirt bike with father

On the other hand, electric dirt bikes require very little maintenance beyond checking the tire pressure and inspecting the chain. Even when you wind up replacing the battery, it should only set you back $40 – $50 bucks.

Keeping an internal combustion engine in top running form can add up quickly if you ride with any regularity.

How Much Should I Expect To Spend for Dirt Bike Maintenance?

To help you plan for dirt bike maintenance, consider some of the areas of expense you can expect:

  • Fuel: Gas-powered engines run on the same fuel as cars. Of course, gas prices are continually fluctuating, but fuel may run you about $500 per year.
  • Tires: One new tire alone can cost between $70 and $100. If you ride frequently, the tires will wear out quicker. Since the tire is what keeps you on the bike and off the dirt, it’s essential to replace them as needed. This can turn into several times a year. Even replacing each tire twice at $100 each adds up to $400 per year.
  • Insurance: Insurance covers property damage to the bike and bodily injury. Depending on the type of dirt bike you have, you can expect to pay anywhere from $25 to $80 per month, or $300 to $1,000 annually.
  • Tools: Working on small engines requires special tools which, while they aren’t terribly expensive, are still an item you need. Consider getting a pressure washer to make cleaning dirt off the dirt bike after a ride much quicker and easier. 
  • Bike Parts: Chains, sprockets, brake pads, and other parts must be replaced from time to time. Costs vary depending on what type of bike you have, but over time these will add up.
  • Oil & Lube: A rough estimate is about $200 per year, but this will vary based on how much the bike is ridden.
  • Costs of a tow vehicle: If you have to drive to a place where your child can ride the dirt bike, you may have to put the bike on a trailer or dirt bike carrier. There will be fuel costs and wear and tear associated with driving to a riding location.

What Riding Gear Does a Kid Need?

No doubt, riding a dirt bike makes for some fun and exhilarating times for your kid. For parents, it can mean concern for a child’s safety. Falls will happen; it’s not a matter of if, but when. The goal is to avoid any severe injuries.

If you’ve gone through the effort to pick out just the right dirt bike for kids, be sure to buy the proper riding gear and insist on it being worn at all times.

tween riding a motocross dirt bike

Dirt Bike Gear List for Kids

Here is our list of must-have safety equipment for your kid to have on their dirt bike:

  • A helmet is the single most critical piece of gear your child needs. This is not a place to skimp on quality by going cheap. A quality dirt bike helmet keeps your kid’s head protected. In many states, this is even a legal requirement.
  • Goggles protect the eyes from dust and debris that gets stirred up while riding. Most dirt bike goggles work for skiing and snowboarding too, so you get multiple seasons of use.
  • A high-quality chest protector works like armor to shield the upper body from injury during a fall. Be sure your child can still move their arms and body well enough with the chest protector on to ride.
  • Knee and shin guards offer protection when a knee goes down during a tight turn, while shin guards protect the lower leg.
  • Dirt bike gloves keep hands from slipping when they get sweaty during the ride. A tight grip from a motocross glove is crucial to maintaining a safe speed and control. 
  • Riding boots are specially designed to protect feet from rocks and debris that may get thrown upwards. Dirt bike boots also strengthen the ankles against impact as the bike twists and turns.
  • Riding jerseys and pants are designed to be tough and protect skin from abrasions and cuts. You can find matching dirt bike pants and jersey sets in kid-pleasing patterns like superheroes (or supervillains)!
  • For longer rides, get your child a backpack with a hydration system. This compact backpack keeps water readily available, as well as any other items like tools.

Does a Child Need a License to Ride a Dirt Bike?

Generally speaking, your child will not need a license to operate a dirt bike as long as you stay off the street. However, suppose you eventually want to ride legally on a commercial or public roadway. In that case, you should check with your local Department of Motor Vehicles to determine what licensing is required in your state.

Although a special license may not be required, it’s a good idea to register your child for an age-appropriate motorcycle or dirt bike safety course to give them exposure to best practices, safety tips, and riding skills.

teenager riding motocross dirtbike

What is a Good Dirt Bike for a 3 to 16 Year Old?

Dirt bikes are not a one-size-fits-all purchase. You’re not going to buy the same bike for a three-year-old as you would for a teenager, even if both are beginning riders. Let’s take a look at several age ranges and bike recommendations for each.

Choosing a Good Dirt Bike for a 2 – 3 Year Old Kid

Young, toddler aged kids between 2 – 3 years old should start with an electric dirt bike that runs on one or two 6 volt batteries and has a training wheel attachment. You won’t have to be concerned about your preschooler going too fast with one of these.

best dirt bike for preschooler burromax tt250 electric motorcycle

The Burromax TT250 runs on a 24v battery with an 8-hour life on a full charge. Your youngster will be excited that his bike looks like a big bike. Seat height is 21 inches, and its top speed is 14 mph. However, with the onboard speed controls, you can dial back that max to 7 mph.

What is a Good Dirt Bike for a 4 – 6 Year Old Kid?

With experience, young kids in the 4 – 6 age group may be ready to graduate to a gas-powered dirt bike. If they’re not, that’s okay. There are still great electric models that will offer slightly higher speeds if that’s the goal:

  • The Razor MX350 is an electric bike that sources its power from two 12v batteries that give 30 minutes of continuous use. You can attach training wheels for the youngest riders who are still learning to balance on the bike.
  • A gas-powered choice to consider is the Yamaha TTR-50. With a 50cc 4-stroke engine, the TTR-50 has an automatic clutch with three gears but also works well staying in one gear for a whole ride if needed. It offers throttle limits and an electric start on the motor.
  • While Yamaha is one of the best in class bikes, it may be out of your budget. If it is, consider a more economical option like the X-Pro Zephyr. This 40cc 4-stroke caps out at 20 mph. It doesn’t have a throttle, but is slow to take off so it stays manageable.
  • With a 2-stroke engine, the Yamaha PW50 is a single-speed bike with a seat height of 18.7 inches. It’s fully automatic, so your kid only needs to twist the throttle to go. It tops out at 28 mph.
  • Much like the 4-stroke option, there are more budget friendly alternatives in 2-stroke. The Syx Moto 50 cc dirt bike has a 2-stroke engine with an automatic transmission. It maxes out at 30 mph, but offers a speed limiter which may bring it as low as 15 mph.

best dirt bike for kids ages 4 to 6 razor mx350

A Good Dirt Bike for a 7 – 9 Year Old Kid

The Coolster 70cc Pit Bike is an excellent choice for the 7 – 9+ year old crowd. Whether kids are trail riding or mudding, this bike’s four gears and semi-automatic motor makes for a fun ride. It can reach top speeds of 30+ mph and carry up to 130 pounds.

best dirt bike for kids ages 7 to 9 coolster gas mini bike

What is a Good Dirt Bike for My Age 10 – 12 Tween Kid?

The KTM 85SX bike offers multiple tire sizes and seat heights to accommodate the growth experienced during the tween years. Designed as more of a competitive racing bike, the KTM is a 2-stroke 85 cc engine and boasts a 35-inch adjustable seat height.

For those who prefer to go electric-powered, try the Razor MX 650 Motocross bike. It’s an excellent choice for this age group because of the larger tire size and seat height (25 inches). With a 17 mph top speed, it’s still fast enough to provide the exhilaration a kid is looking for.

razor mx650 electric motocross bike

Picking A Good Dirt Bike For Ages 13+

Bigger teenage kids warrant bigger bikes, for sure in height, but also in the cc power. If they’ve been riding a while, they probably have the skills and weight to handle a faster bike.

However, remember that higher cc’s equals more speed, so be cautious about putting a teenaged beginner on a faster bike. It may be better to stick with lower cc’s until they get the hang of riding.

For a teen new to dirt bike riding, the Kawasaki KLX 110 makes a solid introductory choice. It’s a user-friendly bike with an automatic clutch and 26.8-inch seat height. Its taller cousin, the KLX110L dirt bike, offers a 28.7-inch seat height and four speeds with manual clutch.

Ready to rocket? For an exciting ride, hop on the Apollo DB-X18 dirt bike. With a top speed of 55 mph powered by a 125cc, 4-stroke engine, the Apollo is a thrill-seeker’s dream. It has a kick start and four-speed manual clutch. The seat height stands at 36 inches so be sure your child can sit comfortably and safely on the bike.

best dirt bike for teenagers apollo dbx18

Final Thoughts

Selecting the right size dirt bike for kids is the first step in creating memorable moments in the backyard or on a track. With a properly sized bike, the right riding gear, and some practice, your child will feel confident and capable of handling his current bike as well as the ones they’ll grow into later on.

Additional Ideas for Dirt Bike Enthusiasts

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