Why Are Dirt Bikes So Loud?

Why Are Dirt Bikes So Loud?

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One recurrent issue bikers and residents aren’t most comfortable is the roar dirt bikes make in the neighborhood. But why are dirt bikes so loud? What’s responsible for the loud sound? How can the loud noise be reduced?

If you have been going through a similar experience and asking related questions with no clear-cut and convincing answer, stop your search. I’ve gotten a comprehensive and practical solution to why dirt bikes are so loud. And it doesn’t matter if you ride the best dirt bikes around; loud noise is a typical feature to bikes.  

Dirt Bikes are very loud because they have short exhaust systems, air and exhaust don’t have residence time to slow down, the engine lacks compartment casing and the size of the dirt bikes muffler. Two-stroke dirt bikes produce louder noise than four-stroke dirt bikes. We’ll talk more about this later on. 

I’m confident by the time we go through this journey together for the next 20 minutes or so; you’ll have had all answers at the tip of your lips.

Let’s hop into the boat quickly and unravel the secret behind the loud noise from your dirt bikes.

Why So Loud?

Let me start from the general consideration before we move to the specific case of dirt bikes’ loud noise. Typically, four factors should come to mind immediately. You notice your dirt bikes make a loud noise. One is the size of the bike’s muffler. Two, you need to look at the length of the exhaust pipes.

The third factor is to know that the air and exhaust don’t have residence time to slow down. Fourthly, the bike engine may lack compartment casing, which should be in place to stifle the sound that results from the engine’s exposure to air and atmospheric conditions.

Why are Dirt Bikes So Loud?

Now, let me go a little bit to the specific reasons dirt bikes are loud. Generally, the loud sound that often comes from the machine is mainly due to a similar number of factors.

The size of the muffler and the length of pipes are two significant interrelated factors to consider. Again, the high revolutions per minute (RPM) of dirt bikes constitute significantly to the loud sound that a dirt bike will give out. Two-stroke dirt bikes produce more deafening noise than four-stroke dirt bikes. Maybe you want to look in that direction. Do you accelerate or cruise with your dirt bike? If you do accelerate, then your dirt bikes may release much noise. Lastly, you need to check if there’s wear and tear on the dirt bike.

We’ve got to open up this discussion a bit so we can take these points home. Let’s look in detail at how each of these factors contributes to the loud sound that emanates from your dirt bikes.

Size of Muffler & Pipe

The size of the muffler and length of exhaust pipes of your dirt bike goes a long way to determine the degree of sound it releases. The size of the muffler and length of pipe of your dirt bike goes a long way to determine the degree of noise it releases. Generally, mufflers and pipes are responsible for sound creation in a dirt bike. The sound can get higher or lower depending on the size and type of muffler integrated into your dirt bike.

We can also ask questions about the type of muffler your dirt bike uses along this line of thought. We have a turbo style muffler, straight-through muffler, and a chambered muffler. Chambered mufflers produce less noise due to built-in friction-enabled grooves. The straight-through muffler is best to regulate noise from the dirt bike, thanks to its capacity to absorb noise. Meanwhile, the turbo style releases the loudest sound.

Within your dirt bike, the difference in length of your exhaust pipes could cause loud noise. If the pipes are short, they could create a quick-burst of energy to be released by the bike, causing a lot of noise.

Exposure to Atmosphere

One other reason your dirt bike is loud could be that your bike engine is exposed to air and atmospheric conditions. If the sound coming from the pistons is not shielded from going up or down inside the engine, what you find is that the sound becomes loud. Remember, there are multiple of mini-explosions that go on in the engine.

Type of Engine: 2-stroke vs 4-stroke

Typically, 2-stroke dirt bikes are louder than their 4-stroke counterparts. The two engines differ significantly from each other, especially as it relates to the back and forth movement of their pistons within the engine.

The movements cause a different chain reaction in the dirt bike engines. How?

The engine of four-stroke dirt bikes works on a four-step principle of injection, compression, ignition, and exhaust. The exhaust is released only when the piston pushes down the second time. It should be noted that the exhaust in a four-stroke engine doesn’t create as much commotion in the dirt bike as you find with the 2-stroke dirt bike.

As for the 2-stroke engine, combustion is often the result when the piston pulls back. This causes the engine to release loud sounds, leading the dirt bike to be relatively louder than 4-stroke dirt bikes.

Wear & Tear

The age of a bike and its use over time will go a long way to determine whether the bike will create a lower or higher sound. As your dirt bike begins to age, there’s a higher chance that the body parts start to wear and tear down, causing the dirt bike to compromise many things, including its crisp and low sound.

So when you place an old and aging bike side by side a new one, you’ll find out that the old one gives an undesirable noise that could be deafening. And you can easily see the difference. It’s essential to keep up with the parts of your dirt bike. Repair and replace damaged parts with new ones as soon as recommended or desirable.

Revolution Per Minute (RPM)

It’s no brainer if I say and insist that your acceleration determines the pitch of the sound your dirt bike produces at every point in time. If you go at a faster speed, the range of your dirt bike sound is higher.

When it comes to a 2-stroke dirt bike, the sound’s pitch is dependent on the degree of adjustability of the power valves. By that, I mean that if the power valves open at different revolutions per minute, a louder and unusual noise is forcefully released out of the chamber.

As for the 4-stroke dirt bike, the same erratic variation of noise level is produced. However, this doesn’t occur with the power valve but with the carburetor. The width and length of the carb determine the effect it creates on the dirt bike to produce a higher or lower bike.

How do Reduce Noise on Your Dirt Bike

Whether used or brand new, all dirt bikes should produce a low and desirable level of noise; otherwise, they will constitute a nuisance to the public and can be tagged unfit and illegal for street use. When you notice that your dirt bike is not giving the best noise pitch you like, try to do everything possible to reduce it.

The best preventive measure to take is to ensure schedule maintenance, replacing whichever part of the vehicle is worn, torn, bad or damaged.

One of these is the muffler. Check if the source of the cracking noise is the muffler or exhaust pipes. Fix them by replacing mufflers and pipes with small size with longer ones. Also, check if the muffler type you use is compatible with the specific dirt bike. It’s also crucial to check if the tubing is air-tight; check the nut and bolts and ensure they’re properly tightened.

Frequently Asked Questions

Do electric Dirt Bikes produce noise?

In their typical nature and feature, electric dirt bikes are designed to be extremely quiet and produce minimal noise that won’t cause your neighbors to raise highbrow. Unlike gas-powered dirt bikes, electric dirt bikes are powered and run with an electric current generated from the bike’s battery. 
Hence, the noise produced by electric dirt bikes is quite low and minimal to make any impact on the environment and fellow road users. That’s why they’re preferred picks among riders, especially among neighborhood riders.

What are the noise limits for dirt bikes?

When it comes to noise limit, you have to relate with your local transport authorities on this. This is because each state and city has different regulations and laws. While the dirt bikes’ speed determines a lot here, the general consideration is that the noise of your dirt bike should not exceed 80 to 85 decibels.

Conclusion

The next time someone asks you, ‘why are dirt bikes loud,’ I am sure you will have ample answers as reasons responsible for those unusual, undesirable noises. You can point them to the size and type of the muffler, length of the exhaust of pipes, wear and tear, rpm, and the kind of engine they’re dirk bike is using. Also, you shouldn’t have an issue explaining the ways they can reduce noise. After all, your dirt bike should be a fun enhancer, not an ear killer.

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