Going fast on a dirt bike is a blast but you are here because you are wondering how fast a 50cc sized dirt bike can go?

Most 50cc dirt bike models are for kids and can go as fast as 24 to 40 miles per hour. 50cc motocross dirt bikes can reach speeds up to 45mph. If you want your kid to go even quicker, you can invest in aftermarket parts. However, higher speeds are not recommended for off-roading as you can lose control. 

The speed of a 50cc dirt bike depends on a few different variables. However, sometimes going fast on a dirt bike might not be an option.

Things that effect the speed of a 50cc dirt bike

  • Transmission Type
  • Weight
  • Motor type
  • Gearing

For example a Honda CRF50 has a different transmission, motor, and gearing that a KTM 50 SX. Both these 50cc dirt bikes fit within the “50cc” engine size but are totally different dirt bikes.

Basically within the 50cc dirt bike world you have 2 types of dirt bikes

  • 50cc Trail dirt bikes
  • 50cc Motocross dirt bikes

Its important to note this as each has its own top speed.

Dirtbike Sam

50 CC dirt bike gearing has an effect on overall top speed

Smaller Sprocket = Higher top speed

Gearing is also a MAJOR factor when it comes to over all top speed. You can put a smaller rear sprocket on and it will give you an overall higher top speed.

Putting a LARGER sprocket in the rear will gear the dirt bike down, this will result in a LOWER top speed.

50 cc transimissions effect over all top speed

The transmission on these 50cc dirt bikes also has a major effect on the overall top speed. For example the trail 50cc dirt bikes like the Yamaha TTR50 come with a 3 speed semi-automatic transmission. These are big and bulky and only give you 3 gears. 

The transmission on the KTM 50SX is a centrifugal clutch that does not have any gears but as the motor spins faster the shoes on the clutch engage on the rim of the clutch housing transfering the power to the wheels. 

This type of clutch will allow for higher top speed than a stock 3 speed semi-automatic transsmission. 

  • So, how fast is a 50cc dirt bike?

    Commercial 50cc dirt bikes reach speeds between 24 to 40 miles per hour as 50cc motocross dirt bikes can reach speeds up to 45mph. These dirt bikes are primarily for kids between 5 to 8 years of age and can't be driven at maximum speeds as the off-road environment will not allow the dirt bike to go faster.

DirtbikeSam Banner Green

The top speed on most 50 cc dirt bikes is between the following speeds:


24-40 MPH

Fastest 50cc dirt bike

Fastest 50cc Trail Dirt Bikes:

  • Honda CRF 50 Top Speed : 33 MPH
  • Yamaha TTR 50 Top Speed: 32 MPH
KTM 50 SX dirt bike

Fastest 50cc Motocross Dirt Bikes:

  • KTM 50 SX Top Speed: 45 MPH
  • Husqvarna TC 50 Top Speed: 45 MPH
  • Cobra 50 SRX FWE Top Speed: 45 MPH
  • Cobra 50 SRX KING Top Speed: 45 MPH

How to make a 50cc dirt bike go faster:

  1. Gearing
  2. More Power
  3. Aftermarket Exhaust

How do you make a 50cc dirt bike go faster? The first thing is gearing. Start with smaller sprockets and this will allow you to have more top speed. The second is to find more power. This can be done by a better air filter, exhaust system, and engine work. This allows your dirt bike to get more power on the top end, allowing for more power.

However, I cannot stress enough that the sprockets, in the end, are what will have the most effect on your top speed. Changing the 3-speed gearbox on the Yamaha TTR 50 or Honda 50 CRF is going to be VERY tough and not really a possibility for most people.


Overall, the 50cc motocross dirt bikes come with a 2 stroke motor that tends to make more horsepower per cc then a 4 stroke. The trail dirt bikes come with a air cooled 4 stroke motor which are easy to ride but not really built for speed.


KTM 50 SX dirt bike

The FASTEST 50CC dirt bike is a 50cc Motocross dirt bike

Like I mentioned above the Honda CRF50 and Yamaha TTR50 are dirt bikes that are built for trail riding. They cannot go as fast as the 50cc motocross dirt bikes. They are not built for racing.

The 50cc motocross dirt bikes will have the highest top speed of the 50cc dirt bikes!!

Dirtbike Sam

So, if you want the very fastest 50cc dirt bike you will need to go with one of the following 50cc dirt bikes:

Click here if you are interested in other 50cc dirt bikes for kids.