How Fast Does A 85cc Dirt Bike Go?

After a 70ccc or 80cc dirt bike, the next consideration for motocross racing is an 85cc dirt bike. So, you expect it to offer you more speed than the other two. But how fast does a 85cc dirt bike go?

A top-end 85cc dirt bike can reach a maximum speed of 50-65mph, depending on the engine power and stroke, rider’s weight, bike weight, terrain, rider experience, and maintenance.

Other factors that can influence an 85cc dirt bike’s top speed are tire pressure, level of braking, and acceleration. Overall, all these factors have to favor you to hit 50mph + with an 85cc dirt bike.   

Note, however, that dirt bikes rarely go past 35mph unless it’s a motocross event. So, you may never get to an 85cc’s full speed under normal riding conditions.      

Let’s discuss the bike’s basics to help you know what to expect from this dirt-racing speed beast.

how much is a 85cc dirt bike

85cc Dirt Bikes Basics

Generally, the letters cc refer to the engine’s displacement capacity in cubic centimeters. So, an 85cc means the dirt bike’s engine’s displacement capacity is 85 centimeters cubic.

Now, here are the basics of 80cc dirt bikes:

1. Engine Power

85cc dirt bikes mostly come with a liquid-cooled single-cylinder engine with a 6-speed transmission system to go very fast. These dirt bikes also enjoy a horsepower of about 23.49-25.49, which is impressive. It’s part of the reason why they are fast.

2. Engine Stroke

85cc dirt bikes come with either a 4-stroke or 2-stroke engine. In a 4-stroke, air goes through four phases (intake, compression, combustion & exhaust). As a result, there is little emission.

Moreover, the engine runs quiet, and the dirt bike is generally stable, making it better for beginners.

Its downside is that the four phases mean more components which makes the engine heavier, and as a result, slower. Also, the fact that air has to go through 4 phases means it takes longer to hit top speed with a 4-stroke.

On the other side, a 2-stroke only involves the compression and combustion stages. For that reason, the process is quicker, and there are fewer components that make the engine lighter and pretty fast.

The downside is that the dirt bike is noisy and less stable when riding fast. So, these engines don’t favor inexperienced bikers.

3. Bike Weight and Load Capacity

85cc dirt bikes are pretty lighter than options with a 70cc, 65cc, or less. So, while the other options are likely to weigh less than 150 pounds, an 85cc dirt bikes average 160 pounds or slightly more.

The good thing about its weight is that it encourages it to support more load. You can count on these dirt bikes to hold up to150 pounds (68Kgs) or slightly more.  

4. Age and Height

85cc dirt bikes generally suit kids from 9-10 years. However, when determining the right bike size, you cannot rely on age, especially older kids.

Instead, you should consider its seat height and match it with your height. Here’s a table comparing the seat height with respective age and height:

Age/HeightSeat Height
9-10 years (140cm)24-26 inches
157cm31-35 inches
162cm33-36 inches
172cm34-38 inches

So, How Fast Does A 85cc Dirt Bike Go in MPH?

Overall, an 85cc dirt bike can hit a top speed of 50-65mph, depending on whether it’s a 2-stroke or 4-stroke, among other factors.

Let’s see what to expect from each engine stroke.  

How Fast Does A 85cc 4 Stroke Dirt Bike Go?

As discussed earlier, 4-stroke engines are generally heavier than 2-stroke options. That, however, doesn’t make 85cc dirt bike slower.

You can expect top-end 4-stroke bikes to hit a top speed of 50-55mph, depending on factors like rider’s weight, bike’s weight, terrain, bike maintenance, and rider skill.

How Fast Does A 85cc 2 Stroke Dirt Bike Go?

While a 2-stroke is less stable for beginners than a 4-stroke, the speed is much higher. If the riding conditions are conducive, you can expect a top-end 2-stroke 85cc to clock a top speed of 55-65mph.

But overall, a 2-stroke 85cc dirt bike requires experience to handle, which means it’s only best for skilled dirt bikers and racers.

how fast can a 85cc dirt bike go

Who Makes the Best 85cc Dirt Bike?  

While there are several reputable and top-end 85cc dirt bike brands, here are six that lead the line:

1. Honda

Honda is popularly known for the Honda CR85, which can hit a top speed of 65mph. Though Honda discontinued its production in 2007, CR85 remains their most coveted 85cc dirt bike.

Unlike most 2-strokes, Honda CR85 is beginner-friendly, making it ideal for 10-year olds who are getting into dirt bike racing.

2. Kawasaki

Kawasaki is famous for the Kawasaki KX85, which can go as fast as 60mph. Overall, its impressive top speed is due to its powerful 2-stroke 85cc engine with 6-speed transmission.

It’s overall a good entry choice into motocross racing as it is stable and ride-friendly.

3. Husqvarna

When it comes to Husqvarna, the Husqvarna TC85 leads the top speed line with a remarkable 60mph. Husqvarna TC85 comes with a 2-stroke one-cylinder engine with a 6-speed transmission and enjoys a horsepower of 25.36HP.

Those are the reasons behind its explosive speed.

4. Suzuki    

Suzuki takes pride in the Suzuki RM85, which can hit 50-55mph under excellent conditions. That’s all thanks to its liquid-cooled 2-stroke single-cylinder engine with electric ignition.

5. KTM

KTM is another pacesetter in the dirt-biking world. Their KTM85 SX can go as fast as 65mph under excellent conditions.

This dirt bike comes with a 2-stroke liquid-cooled single-cylinder engine with a 6-speed transmission to hit top speed. Plus, it promises a horsepower of 25.36Hp, which is impressive.

6. Yamaha

Yamaha doesn’t make the speediest 85cc dirt bikes, but you can hit 50mph with a Yamaha YZ85 under excellent conditions. This dirt bike comes with a 2-stroke liquid-cooled single-cylinder engine with a 6-speed transmission and 23.49 horsepower to promote top speed.

how fast does a 85cc 4 stroke dirt bike go

Factors Determining an 85cc Dirt Bike Top Speed

Overall, these factors determine how fast an 85cc dirt bike can go:

  • Rider’s weight – The lighter the rider, the speedier an 85cc dirt bike is. That’s primarily because the rider’s weight is part of the dirt bike’s load capacity. So, you are more likely to hit top speed when you weigh less than the dirt bike’s load limit.
  • Bike’s weight – As mentioned, the average 85cc dirt bike weighs 160 pounds or thereabout. Those who weigh more are usually less likely to hit top speed than those who weigh less if all other conditions are standard.
  • Terrain – Though dirt bikes are naturally built for the off-road and not on-road, different off-road conditions affect their performance differently. Overall, expect to go faster on flatter off-roads with fewer obstacles.
  • Rider’s experience – Usually, the more skilled a rider is in dirt biking, the likelier they are to hit top speed. The opposite is equally valid. Less experienced riders tend to go slower not to crash and thus are less likely to reach top speed.
  • Maintenance – Dirt bikes are all about care. The more you service your dirt bike regularly, the likelier traveling at top speed. In that case, learn to tune up your dirt bike, replace defective air filters, and grease up the chain regularly.

Other Factors

Other important factors determining an 85cc dirt bike’s top speed include:

  • Tire pressure – Using the correct tire pressure improves your likelihood of hitting top speed.
  • Level of braking – Usually, the heavier you brake, the slower you go, and the less likely you are to hit top speed.
  • Acceleration – While heavy braking slows you down, acceleration boosts your chances of hitting top speed.

Is an 85cc Dirt Bike Safe?

Realistically speaking, no dirt bike is 100% safe. You can always hurt yourself, especially when riding at high speed. And with 85cc dirt bikes clocking up to 50-65mph, the best you can do is be careful, but more importantly, gear up.

So, consider getting the right dirt bike gears (View on Amazon) to protect the knees, elbows, chest, head, and feet.

85cc dirt bike top speed

People Also Ask

1. How Much Is A 85cc Dirt Bike?

When it comes to top-end brands like Kawasaki, Honda, and Yamaha, 85cc dirt bikes cost between $4,000 and $6,300. Nevertheless, you can get a decent second-hand 85cc dirt bike on eBay, Alibaba, and Craigslist for under $1000.

2. What Is the Fastest 85cc Dirt Bike?

Here are 6 of the fastest 85cc dirt bikes on the market:

  • Honda CR85 (65mph top speed)
  • KTM85 SX (65mph top speed)
  • Kawasaki KX85 (60mph top speed)
  • Husqvarna TC85 (60mph top speed)
  • Suzuki RM85 (50-55mph top speed)

3. How Fast Does A KX 85 Dirt Bike Go?

A Kawasaki KX85 2-stroke can reach a top speed of 60mph under excellent conditions like suitable terrain and weather. More importantly, the engine should be powerful and in good condition, and the rider should be experienced to reach such top speed.

4. How Fast Does an 80cc Dirt Bike Go?

Depending on the dirt bike brand and engine strength and stroke, an 8-cc dirt bike can clock a top speed of 45-65 mph. However, terrain, engine service, rider’s experience, and weight are critical in determining the dirt bike’s maximum speed.

5. How Fast Does A YZ85 2 Stroke Go?

A Yamaha YZ85 in good condition can hit a top speed of 50mph under excellent racing conditions. That’s owing to its powerful liquid-cooled 2-stroke engine with 6-speed transmission.

6. How Fast Does KTM85 Go?

A KTM is pretty fast. You can count on this 85cc dirt bike to hit a top speed of 65mph, which is the highest of an 85cc dirt bike. The road conditions and weather have to be ideal, and you should be experienced to reach such a top speed.  

7. How Fast Does a Honda CR85 Go?

A Honda CR85 can hit a top speed of 50-65mph, depending on the engine strength, model, and biking conditions. Overall, the more ideal the conditions are, the likely they are to hit top speed.

In Conclusion; How Fast Does A 85cc Dirt Bike Go?

Generally, a motocross racing 85cc dirt bike can hit anything between 50 and 65mph, depending on the engine, brand, and riding conditions. But overall, it’s not often that people go past 35mph. That’s unless you ride for motocross competition.