The role of motorcycle muffler

Motorcycle muffler is a device that allows airflow and attenuates noise. It is one of the important parts on motorcycles. The performance of the muffler not only affects the size of the motorcycle noise, but also has a greater impact on the engine's power, fuel consumption, torque and other performance. Therefore, it is necessary for every motorcycle user to understand the principle, structure and maintenance knowledge of motorcycle mufflers.



One, the type of muffler

According to the different noise reduction principles, motorcycle mufflers can be divided into the following three types:

  1. Resistive muffler

This kind of muffler uses the sound absorption effect of the sound-absorbing material or sound-absorbing structure to attenuate the noise propagating along the pipeline with the distance, so as to achieve the purpose of sound elimination. Commonly used sound-absorbing materials are glass fiber yarn, low-carbon steel wire mesh, felt, etc. This type of muffler has a good silencing effect on high-frequency noise, but the low-frequency silencing performance is poor. In addition, because the sound-absorbing material is easily melted by the high-temperature exhaust gas discharged from the engine, the service life is short, and it is easy to be blocked by carbon deposits, sludge, etc., which reduces or loses the sound attenuation effect.



  2. Resistant muffler

This kind of muffler uses the sudden expansion (or contraction) of the pipe section or the bypassing of the resonant cavity, so that the sound waves of certain frequencies propagating along the pipe will be reflected back to the sound source at the sudden change, so as to achieve the purpose of sound elimination. It is more suitable for eliminating low and intermediate frequency noise, but has a poor effect on high frequency noise.


 3. Impedance compound muffler

This kind of muffler is a combination of resistive muffler and resistive muffler's noise elimination principle through a suitable structure, and has the noise elimination characteristics of both. Because the noise frequency band generated by the noise source of motorcycle engine is relatively wide, in order to obtain a better noise reduction effect in the wide range of low, medium and high endurance rates.



 The structure of the muffler

Motorcycle mufflers can be divided into two types: barrel muffler and box muffler according to the shape and structure, which will be introduced separately below.

  1. Cylinder muffler

This kind of muffler is generally a resistive or impedance compound muffler, which is mostly used on medium and large displacement motorcycles.


  2. Box muffler

General mopeds, especially seat-type vehicles, have a relatively small installation space, so box mufflers are often used.