Average Dirt Bike Length (With 17 Examples)

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Whether you are looking for a specifically sized bike, figuring out what size of trailer you need, or are just curious about the length of your own dirt bike, here are some important things to know.

Dirt bike lengths are measured from front tire tread to back tire tread. The average length size for adult bikes is 82.8 inches, and the average size for kid bikes is 52.9 inches.

There is a lot to learn about dirt bike length, and I hope that I can pass some of my knowledge on to you!

Adult Bikes

Adult dirt bikes have an average length of 82.8 inches, but dirt bikes come in various sizes. Adult sized dirt bikes generally have larger engines (from 250ccs to 1,000ccs). The bigger the engine, the heavier the bike.

When you are deciding on what size of a dirt bike to get, it’s important to consider your height, your weight, and your overall body strength. Most people who are learning how to dirt bike generally learn faster on smaller bikes, but it’s totally up to you. Whatever floats your boat…or whatever fuels your bike…

I would suggest, however, to make sure that you try out the bike–like actually sit on it, even go for a test ride if possible–to make sure it’s the right size of bike for you.

So, what’s the deal with dirt bike length?

Size, from height to weight to length is very important in considering what bike to buy and/or how you need to adjust your bike. If you have an ill-fitting bike, it’s not only uncomfortable to ride on but also unsafe.

As far as length goes, you want to make sure that the bike isn’t too long for you. Generally speaking, the longer the bike is, the heavier the bike will also be. Heavier bikes are harder to control, so I would steer clear of these monsters until you’re ready to tame the beast–or, in other words, have more experience riding.

It’s not always best to try out the bigger, “badder” bike. It may look cool but may also be super uncomfortable to ride on and, therefore, a waste of money.

So, what should you look for as far as length goes?

When you sit on the bike, as you should hopefully do before you pull out your wallet, here are a few things to keep in mind:

1. Do you have to strain to reach the handlebars?
2. Are you able to maneuver the handlebars easily enough for steering the way you need to while riding?
3. How far back is the bike’s seat (and, therefore, you) from the handlebars?
4. Could the distance between the seat and the handlebars be adjusted to suit your needs/preferences?
5. How is your comfort level, as far as the bike’s size and length?

You’ve definitely got to keep in mind that just sitting on the bike–feeling it out–and going for a test drive are totally different experiences. Both are helpful in determining if it’s the right bike for you, but you shouldn’t rely on only sitting on the bike to get a general feel for it.

You need to experience how actually riding the bike feels on flat or rocky terrain to know for sure if it’s the right size for you to enjoy yourself and be safe. If you don’t have the opportunity to actually take the bike out before buying it, then do your best to watch videos of people giving the bike a try for the first time.

Here are some examples of adult dirt bikes and their lengths:

What’s the difference between a longer bike and a shorter bike?

Besides the overall weight of the bike, there are some other things to keep in mind about the bike’s length. Generally speaking, a longer bike will also have a bigger build. This will affect the wheelbase of the bike, which is a major aspect that you want to pay attention to.

The wheelbase of a dirt bike is the distance between the center of each of the bike’s wheels. That seems pretty simple, right? Well, the wheelbase actually has a lot more to do with the performance of the bike while you’re riding.

Shorter Wheelbase

The shorter the wheelbase on a bike, the quicker it responds to turning. So, if you’re into the fast and the furious with dirt biking, a shorter wheelbase might be the right kind for you.

Keep in mind, though, that the shorter the wheelbase, the less stable the bike will be in turning your bike along the path. A bike with a shorter wheelbase will also be more sensitive to weight shifts while you’re riding, so you’ll need to keep a good balance while riding with a wheelbase adjusted this way.

Longer wheelbase

The longer the wheelbase of your bike, the more stable it will be when riding on straighter paths. This can be a great advantage to the speed of your bike because it won’t be as difficult to control.

The increased stability of a longer wheelbase, however, will require you to lean into your turns more than a bike with a shorter wheelbase.

Depending on your plans for riding your dirt bike (whether racing, training or smoother sailing), it’s to your advantage to pick a bike with the desired wheelbase possible lengths and adjust it as you need to.

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How do you adjust your bike’s wheelbase?

Before you start tinkering around and making different kinds of adjustments on your bike, you should take your bike out for some test runs. Depending on the terrain that you ride on, you may need to adjust the wheelbase of your bike in different ways to achieve the greatest comfort and performance for your purposes.

The effect that your wheelbase has on your bike is closely related to your suspension and fork height. You can adjust your bike’s suspension by adjusting the clickers and the rear shock sag.

Going an inch forward or backward on the wheelbase may require you to replace your chain with a longer or shorter one if you change the position of the rear wheel of your bike.

For adjusting the fork height, you can use an aftermarket triple clamp set. This will enable you to handle any height problems on your bike.

What size trailer/truck do I need for my bike?

It’s so important to consider what size of trailer you need to transport your dirt bike(s). The size of the trailer (whether open or closed) depends a great deal on how many bikes you will be transferring.

Generally speaking, an appropriate trailer size for two dirt bikes is 5 feet by 8 feet. This will fit two dirt bikes both with handlebars up to 3 feet wide and bike length being about 7 feet long (which is the average bike length). This size of trailer will give you plenty of room for fudging in case one or both of your bikes is a little bigger, while also allowing you to move about the trailer as needed.

If you’re moving three dirt bikes, a better-sized trailer would be 6 feet by 10 feet. Remember, you probably aren’t going to want to maneuver around bikes that are too tight together while you are loading them up, tying them down and taking them out. You want plenty of space to do a good job and take care of your bikes.

If you’re moving four bikes, a trailer that is 6 feet by 12 feet will fit them all with some space to spare for other equipment. Five bikes, however, in this size of trailer will be a close call. In this case, getting a trailer that is wider instead of longer should fit all your bikes stupendously.

Kids Bikes

I included kids dirt bikes because their sizes are drastically smaller and are a category all their own. Kid dirt bikes have the lowest engine size of 50cc, but as kids become more skilled at dirt biking grow, they will graduate into larger engine bikes.

The length of dirt bikes can have an effect on the comfortability of riding, especially for kids who are learning. If your kid (or you) have to extend your arms out far from comfort just to reach the handles, the bike likely is too long or its wheelbase needs to be adjusted to a more comfortable length.

Here are some examples of kids dirt bikes that I found, and bikes on this list would fit a kid anywhere between 6 and 14 years old.

What bike lengths and engine levels are the best for different ages?

Depending on your child’s age, height and experience, you need to consider what size dirt bike is appropriate for them. Generally, the biggest thing to consider is how comfortable your child is on a certain size of dirt bike, as well as now able they are to control the dirt bike’s size.

Make sure to check that your child can reach the handlebars comfortably and that both of their feet can be flat on the ground while they are stagnant. For your kid’s SAFETY as well as fun, you want to ensure their bike fits them the right way no matter their age or experience. This isn’t’ the time for “Oh, you’ll grow into it.”

Children, age 6 or younger

If your kids are just starting out with dirt biking, it’s best to find a bike with a 50cc engine. This level of the engine will mean the bike is generally lighter, (therefore, easier to control) and will also be smaller.

Children, age 7-10:

For this age group, engine ranges between 70cc and 80cc are some of the best choices, whether your child has been riding since they were younger or are just starting out.

These bikes a generally bigger than 50cc bikes, so they will accommodate for the frequent growth spurts these kids go through that leave you wondering how much time has passed.

Children, 10 and older:

As your kids get older, engine sizes get bigger; these engines can range anywhere between 85cc to 150cc. Since this is the age group where your child will need a bigger, taller bike, the most important factor to consider here is how comfortable your child is riding these bikes and how well they are able to handle them.

Many adults actually ride the 50cc dirt bikes as a little toy, but never for a substantial amount of time or distance. I mention this because there really is no harm in getting a dirt bike that is too small for your kid, it just won’t be as fast or be able to get them up steep hills.

What size bike is too big for your kid?

In truth, dirt bike length has nothing to do with the correct sizing of a bike. I would say the more important factor is how tall the seat on the dirt bike is. Look into the right seat height of dirt bikes for your kid instead of just the dirt bike length.

Many children, like when you take them shoe shopping, have trouble looking past the aesthetics of the bike. Before making any sort of purchase, have your child get on the bike and see if they have to really stretch in order to reach the handlebars, or if their feet can touch the ground. If you planned on surprising your kid with a bike, see if you can find a friend with a similar sized bike or a similar sized child.

Of course, its always better to lean on the larger side when it comes to kids since they will grow into bikes and eventually outgrow them. That being said, bigger isn’t always better. Never get a bike that might be too much for your child to handle. Forcing them to stretch a little and move around on their tippy toes is fine, but having a bike that has too much power and too much weight is dangerous.