Dirt bikes are like clothes, you don’t want them too big, but you don’t want to outgrow them either. Since this is the case, it should come as no surprise that purchasing the right-sized dirt bike is easier for full-grown adults. However, if you’re younger or shopping for someone younger, you need to make a compromise and find a bike small enough to provide a safe ride but not too small that you find yourself shopping for a new bike within a year or two.
At Motomentum, we eat, sleep, and breathe dirt bikes. If you find yourself asking, “what size dirt bike should I get?” You’re in the right place. Our experts will walk you through the different things you should consider when trying to find the perfect-sized dirt bike for yourself or a loved one.
How Are Dirt Bikes Measured?
Dirt bikes are measured by the total seat height and the engine displacement. Engine displacement refers to the engine’s overall power and is typically the number used when describing dirt bikes.
Engine displacement size increases with power in the sense that a 50cc is weaker than a 125cc, 250cc, 450cc, and so on.
A two-stroke engine completes an engine cycle in half the time it takes a four-stroke engine to do the same. This means a 250cc two-stroke will have more peak power than a 250cc four-stroke. However, this does not automatically mean that a two-stroke is preferable to a four-stroke, and for most riders, it’s not.
At the end of the day, the optimal engine size depends on the rider, their familiarity with dirt bikes, and their riding ability. The important metric when finding the perfect-sized dirt bike is the seat height.
Seat height scales more or less with engine displacement in that a 125cc is generally shorter than a 250cc. However, this is not always the case since seat height differs between makes, models, and intended use.
What Size Dirt Bike Do I Need?
Since it is impossible to assess rider ability without seeing the rider do their thing, this section will focus on rider height compared to seat height.
Riders between 3 and 4.5 feet tall should look at dirt bikes with seat heights of 22-26 inches. These will include your bikes with an engine displacement of 50cc to about the 110cc range. If the rider is going to use training wheels, you can go taller since balance won’t be an issue.
For riders between 5 and 5.5 feet tall, we suggest a seat height between 26 and 36 inches. Over 5.5 feet tall can exceed 36 inches, but dirt bikes rarely reach a 39-inch seat height. It is important to note these are just generalizations and not strict guidelines.
At the end of the day, the best way to tell what size dirt bike is right for you is to go sit on some. Just remember that dirt bikes are measured by engine size as well as seat height. Just because you’re older and tall enough to ride a 450cc doesn’t mean you should. Make sure to find a bike that is within your skill range and one that you can comfortably balance on while stopped.
Contact Motomentum for More Information
If you’re still unsure about what size dirt bike is right for you, we recommend stopping by your local dealer. If you know what size bike you need, check out our online selection of gas-powered dirt bikes or give us a call for more information.
