How Fast Does 70cc Dirt Bike Go
If you’re thinking about buying a 70cc dirt bike, or you’ve seen one at a local track, you may wonder just how fast these small machines can go. While 70cc sounds modest compared to bigger bikes, these motorcycles are popular among young riders and beginners for good reason. Their speed, safety, and performance all play a role in whether a 70cc dirt bike is right for you or your family.
Let’s explore the real top speed of a 70cc dirt bike, what affects its performance, and why speed is only one part of the story. You’ll also find practical advice, comparisons, and answers to common questions that people have before buying or riding a bike of this size.
Average Top Speed Of A 70cc Dirt Bike
Most 70cc dirt bikes reach a top speed between 30 to 40 miles per hour (48 to 64 kilometers per hour). The exact speed depends on the brand, model, and several other factors, but almost all stock (factory) 70cc bikes fall within this range.
For example:
- The Honda CRF70F can reach around 35 mph.
- The SSR 70 is often measured at about 30 mph.
- The Coolster 70cc may hit 37 mph with a light rider.
These numbers are based on manufacturer claims and real-world tests by riders. It’s important to note that while these bikes can reach these speeds, most young or beginner riders don’t ride at top speed for long. They usually stay much lower, especially on rough or twisty trails.
What Factors Affect The Speed Of A 70cc Dirt Bike?
A 70cc dirt bike’s speed isn’t only about engine size. Several elements work together to determine how fast the bike actually goes in real life.
1. Rider Weight
Heavier riders will slow the bike down. Most 70cc dirt bikes are designed for kids or smaller adults—usually under 130 pounds (60 kg). If a heavier rider gets on, expect the top speed to drop by 2-5 mph.
2. Terrain
On flat, paved surfaces, a 70cc dirt bike will achieve its highest possible speed. On dirt, sand, or uphill trails, the speed drops, sometimes sharply. Many bikes can lose up to 10 mph when climbing a steep hill.
3. Gearing
The gears (sprocket sizes) control the balance between speed and torque (pulling power). Some bikes come with gearing for quick acceleration, which lowers the top speed. Changing the front or rear sprocket can increase top speed, but may reduce low-speed power.
4. Engine Condition
A well-maintained engine runs faster and smoother. Dirty air filters, old oil, or worn-out spark plugs all cut down the bike’s speed. Regular maintenance makes a noticeable difference, especially as the bike ages.
5. Weather And Altitude
Colder air and lower elevations help engines produce more power. If you ride at high altitude or in very hot weather, the bike may feel weaker and slower.
6. Modifications
Some owners upgrade the exhaust, intake, or carburetor to get a few extra mph. These modifications are usually not recommended for beginners but can make a measurable difference for experienced users.
How 70cc Dirt Bikes Compare To Other Sizes
Choosing the right dirt bike isn’t just about speed. Let’s see how a 70cc stacks up against other common sizes.
| Bike Size (cc) | Top Speed (mph) | Typical Age Group |
|---|---|---|
| 50cc | 20-28 | 5-7 years |
| 70cc | 30-40 | 7-11 years |
| 110cc | 40-50 | 8-13 years |
| 125cc | 45-55 | 12+ years |
You can see that 70cc bikes are a step up from 50cc models, offering more speed and power, but they’re still manageable for young or lighter riders. They’re much slower than adult-size 125cc bikes, which often go above 50 mph.
Real-world Speed Tests
Lab numbers are one thing, but how fast do these bikes go in real-world conditions? Several online tests and user reviews show the following:
- A Honda CRF70F with a 75-pound rider reached 34 mph on flat ground.
- A Yamaha PW80 (which is 79cc but similar in power) hit 37 mph with a 90-pound teen.
- On a bumpy trail, the top speed was usually 5-8 mph lower than the maximum.
These tests prove that conditions and rider size make a big difference. Even on the same bike, a heavier adult might only reach 30 mph, while a light child could approach 40 mph.
Credit: www.tribalmotorsports.com
Why Speed Isn’t Everything
While the question “How fast does a 70cc dirt bike go? ” is common, speed alone doesn’t decide if this bike is right for you. There are a few other factors to consider.
Safety
70cc dirt bikes are built for beginner and intermediate riders. Their lower top speed makes them safer for kids learning to ride. High speeds can be dangerous without the right skills and protective gear.
Learning Curve
The power delivery is smooth and predictable. This helps new riders build confidence. A bike that’s too fast can cause accidents or bad habits.
Legal Rules
In many places, there are limits on where you can ride dirt bikes and what ages are allowed for certain engine sizes. Always check your local laws before buying or riding a 70cc bike.
Non-obvious Insight: Speed Governors
Many 70cc bikes come with a speed governor—a device that limits how fast the bike can go. Parents or teachers can adjust or remove these, so if your bike is much slower than expected, check if a governor is installed.
Key Features Of A 70cc Dirt Bike
A 70cc dirt bike is more than just its engine. Here’s what makes these bikes popular with families and young riders:
- Automatic or Semi-Automatic Gearbox: Many 70cc bikes use automatic or semi-automatic transmissions, so new riders don’t have to worry about a clutch.
- Electric Start: Most models have an electric start, making them easy for kids to use.
- Lightweight: They usually weigh less than 120 pounds (54 kg), so they’re easier to pick up after a fall.
- Low Seat Height: The seat is low enough for most kids ages 7-11 to touch the ground easily.
- Affordable Parts: Replacement parts and maintenance costs are lower than bigger bikes.
Credit: www.killermotorsports.com
How To Make A 70cc Dirt Bike Go Faster (safely)
If you feel your 70cc dirt bike is too slow, there are a few safe ways to increase speed. But remember—more speed means more risk.
- Check Tire Pressure: Underinflated tires slow the bike down. Keep tires at the recommended pressure.
- Maintain the Engine: Clean the air filter, change the oil, and check the spark plug regularly.
- Upgrade Gearing: Switching to a smaller rear sprocket or larger front sprocket can add 2-3 mph. However, this may reduce low-speed power.
- Aftermarket Parts: Some riders use a performance exhaust or a better carburetor, but these changes can void warranties and increase wear.
- Remove the Speed Governor: If installed and you’re sure the rider can handle more speed, removing or adjusting the governor allows the bike to reach its true top speed.
A non-obvious tip: Don’t overlook chain tension. A loose or rusty chain can rob the bike of speed and cause damage. Keep the chain tight and lubricated.
Common Mistakes When Judging 70cc Dirt Bike Speed
Many new buyers or parents make similar errors when researching speed.
- Assuming all 70cc bikes are the same: There are variations between brands and models.
- Ignoring terrain: Speed on grass or sand is much lower than on pavement.
- Believing “faster is better” for kids: Too much speed leads to loss of control and crashes.
- Not considering future growth: Kids may quickly outgrow a 70cc bike if they are already tall or skilled.
- Overlooking safety gear: A helmet, gloves, and boots are as important as the bike itself.
Credit: www.hypergogo.com
Top 70cc Dirt Bike Models And Their Speeds
Here are a few well-known 70cc models, along with their typical top speeds.
| Model | Top Speed (mph) | Transmission |
|---|---|---|
| Honda CRF70F | 35 | Semi-Automatic |
| SSR 70 | 30 | Automatic |
| Coolster 70cc | 37 | Semi-Automatic |
| YCF 70 | 36 | Automatic |
Remember, these speeds are with an average-size child and good conditions. Your results may vary.
Is A 70cc Dirt Bike Right For You Or Your Child?
A 70cc dirt bike is best for:
- Kids ages 7-11 who have some riding experience
- Smaller adults who want a fun, lightweight bike
- Families looking for a safe, reliable beginner option
It may not be right if:
- The rider is much heavier than 130 pounds (60 kg)
- You want to do serious racing or extreme riding
- The rider is already too tall for the bike
The best way to decide is to try the bike in person. Make sure the rider can touch the ground with both feet and feels comfortable with the controls.
How To Ride A 70cc Dirt Bike Safely
Speed is exciting, but safety comes first. Here’s how to enjoy your 70cc dirt bike without unnecessary risks:
- Wear a Helmet: Never ride without a quality helmet.
- Use Protective Gear: Gloves, boots, and long sleeves protect against injury.
- Start Slow: New riders should practice at low speeds until they are confident.
- Ride in Safe Areas: Use legal tracks or private land, not public roads.
- Supervise Young Riders: Adults should always watch children on dirt bikes.
- Follow Maintenance Schedules: Regular checks prevent breakdowns and accidents.
Frequently Asked Questions
What Is The Real Top Speed Of A 70cc Dirt Bike?
Most 70cc dirt bikes reach between 30 and 40 mph (48-64 km/h) on flat, smooth ground with a light rider. Actual speed may vary depending on the brand, rider weight, terrain, and maintenance.
Can An Adult Ride A 70cc Dirt Bike?
Yes, but it’s not ideal for most adults. The bike will go slower with heavier riders, and the seat and controls may feel cramped. These bikes are designed mainly for kids and smaller teens.
How Does A 70cc Dirt Bike Compare To A 50cc Or 110cc?
A 70cc bike is faster than a 50cc (which usually tops out at 20-28 mph), but slower than a 110cc (which can go 40-50 mph). It’s the middle ground for beginner and youth riders.
Is It Possible To Make A 70cc Dirt Bike Go Faster?
Yes, you can increase speed by keeping the bike well-maintained, adjusting tire pressure, changing sprockets, or making small performance upgrades. However, always consider the rider’s skill and safety first.
Where Can I Find More Information About Dirt Bike Models And Safety?
For official details and comparisons on dirt bike models, engine sizes, and safety, visit the Dirt Bike Wikipedia page.
A 70cc dirt bike offers a great mix of speed, safety, and fun for young riders and beginners. While 30-40 mph may not sound extreme, it’s more than enough for learning, trail riding, and building confidence. Always focus on the rider’s skill, safety gear, and proper maintenance—speed will follow naturally. If you’re considering a 70cc bike, test ride one and see if it matches your needs, and remember: a safe, happy rider is always faster in the long run.