Dirt Bike Noises – Why the Loud Sound?
When you visit dirt bike racing, chances are that you will hear the deafening roar of the bikes. There are many of you who may often wonder why these bikes make such loud noises. In fact, this is one of the questions that many fail to answer. If you have a dirt bike of your own, you will soon get acclimatized to the noise. However, what makes all that noise and how loud the noise is will definitely help you get the answer to reduce the loud and deafening noise.
How Loud Is A Dirt Bike?
When it comes to the degree of loudness, there are different factors to consider for your dirt bike. Most of you know that the loudness of noise is measured in decibels. Some of the factors to consider include the make and model of the bike, the RPMs of the bike, and the nature of pipes used while formatting the dirt bike. Add to that the fact that the speed at which you ride the bike will also determine the loudness of the bike. The speed at which you are riding may result in different degrees of noise produced.
There was a study carried out in the state of California. The study stated that the sound produced by any dirt bike should never exceed 96 decibels. This value is more or less similar to that of a quiet roar. It is also the most comfortable sound that is considered to be good and also recommended for all types of dirt bikes. Nonetheless, different states have different laws when it comes to the use of dirt bikes. Although the decibel level of every dirt bike will differ from time to time, the noise produced will largely depend mainly on the way a bike was made and the speed at which you normally ride the bike. These factors also prove to be important when it comes to the performance of the bike.
What Is The Source Of The Noise?
It may so happen that your dirt bike produces a loud noise due to its high revolutions per minute or RPM, the frequency at which you accelerate rather than cruising, and the short mufflers. All of these are primary factors that contribute towards creating noise in the bike. You will be surprised to know that 2-stroke bikes are much louder than the 4-stroke bikes. This is despite the fact that the noise level of a 4-stroke dirt bike is much higher in comparison.
Apart from RPMs and mufflers, there are various other factors that can also influence the production of loud noises in a dirt bike. However, it is not as simple as you may think to point out the exact reason for loud noise in a dirt bike. To keep things simple, all the factors work as a team to produce the loud noise in one way or the other. Here are some of the common factors that produce loud noise in dirt bikes.
Revolutions per Minute (RPM)
The sound produced by your dirt bike mainly depends on the speed at which you move your bike. For example, a 2-stroke dirt bike will create noise that will depend on the way its adjustable power valves work. This basically means when the valves open at different RPMs the bike will surely make some erratic noises. On the other hand, a 4-stroke bike will experience a somewhat similar variation of the levels of noise produced. However, in the case of a 4-stroke bike, the difference will be created by the settings of the carburetor. Basically, the noise will depend on the width and length of the carburetor.
Pipes and Mufflers
Pipes and mufflers are basically responsible for the production of loud noises in a dirt bike. Depending on the type of mufflers in your bike, the level of noise produced may get higher. Some examples of mufflers may include turbo style muffler, chambered muffler, and straight through muffler.
The turbo style muffler is basically shaped like an “S” in order to absorb most of the sound while releasing the rest. At the same time, chambered mufflers have grooves inside that cause some amount of friction. This, in turn, helps to reduce the noise. On the other hand the straight through muffler is mainly a standard piping. It absorbs some amount of noise, due to which it successfully reduces the sound produced.
As far as the pipes inside your dirt bike are concerned, the situation somewhat changes to something different. The reason behind this is the fact that the pipes come in varying lengths. This causes quicker bursts of energy produced by the bike. Due to this fact, loud noise is created because more and more bursts of energy pass out through the pipes. It is also true that when the pipes are shorter, the level of noise created rises compared to the level of noise when the pipes are longer.
Wear and Tear
It will sometimes be wrong to say that various parts of a dirt bike are the sole factors behind the higher or lower noise levels. In fact, a used or old dirt bike may easily produce more noise like most other parts of a dirt bike. When your bike starts getting older, there are several parts that experience wear and tear. This may lead to the production of undesirable noises while riding. Thus, it will be a good idea to make sure that you check and replace all the old and worn out parts of your dirt bike. This will help to minimize the loud noises.
Which Is Louder? 2-Stroke or 4-Stroke?
When it comes to dirt bikes, there are basically two types available in the market. These are 2-stroke and 4-stroke bikes. Both of these bikes differ from each other greatly in the manner their pistons move in a bike engine. When you talk about the strokes, it refers to the total number of times the pistons move back and forth in an engine. This leads to chain reactions in the engine.
Most of you may wonder how the sound gets produced in the process. The sound that comes out of a running bike is created due to the number of times the pistons push out the exhaust from the engine. When you talk about a 4-stroke bike, the engine follows a specific series. This is basically injection-compression-ignition-exhaust. This is why the term 4-stroke is used. This entire process happens in a pretty simple way. Every time the piston pushes down for the second time, it forces the releases of the exhaust.
It is important for you to know that the exhaust does not produce a lot of chaos in a dirt bike as it does with a 2-stroke engine. When it comes to a 2-stroke bike, each time the pistons pull back, the combustion takes place. As a result of this, the engine produces comparatively louder noise than a 4-stroke bike. The way a 2-stroke and a 4-stroke bike work is the primary determinant of the noise type that gets created. Thus, you may know by now that a 2-stroke dirt bike is much louder than a 4-stroke one.
How to Reduce Noise on a Dirt Bike?
Whether a dirt bike or brand new or second-hand it really does not matter. It should simply be in a proper working condition while producing low levels of noise. If this is not the case, it is important that you find the best possible way to decrease the loudness. This will help people around get less upset with the noise of your dirt bike and also help you ride around peacefully. It is important for you to remember that these bikes ten to make loud noises as they age.
During this time, you will realize that a few parts of your bike are getting loose or wearing out. As a result of this, the loudness of the noise produced gets unbearable for some. In order to overcome the loudness of a dirt bike, you will have to take huge steps before the situation gets out of hand. Firstly, you need to check the muffler of your bike and see whether it is the root cause of all the unpleasant noise.
As discussed above, shorter mufflers are the primary causes of loud noises. You can easily fix the problem that will allow the muffler to absorb the majority of the noise produced by your dirt bike. Secondly, it is important that you check all the parts of the dirt bike to locate those that require immediate replacement or repair. Check whether the tubing is air-tight and if needed try and fix it. It is essential that you check every nut and bolt of your bike. This will help you make sure that these are not loose and are secured nicely.
It is important that you try and make sure that the overall performance of the dirt bike is optimal by simply fixing every factor that may be contributing to the loud noise. Ensure that the bike itself is working properly and is not violating the law in any way.