The bending exercises of radial tire is one of the most important structural properties of the sidewall relating to ride and road noise of automobiles. The frequency band analysis is more useful for analyzing tire road noise due to property change of tread and sidewall. In this paper, the vertical stiffness and lateral stiffness of tire which have a various tread and sidewall is measured and the road noise is measured about same road condition. Furthermore, we investigated the effect on the structure of the tire tread and sidewall for the sound pressure level.

A deformation of tire structure cause characteristic change of tire as stiffness, ground surface shape, vibration and noise. As a result it will affect "riding quality" factors such as noise and vibration. In this study, figured it out the difference of tire pass by-noise according to ground pressure and stiffness change, to investigate the influence of tire characteristic for tire pass-by-noise. Therefore, The tire ground stiffness and tire pass-by-noise was measured according to pass-by-noise test method(ECE R117). Conclusively, “The tire pass by noise” was confirmed that between vibration and tread shoulder are a close relationship. As the tire shoulder vibration is low, “The acceleration pass-by-noise” can be seen that displayed lower value. In order to distribute contact pressure low for reduce the acceleration pass-by-noise, it could be confirmed that the shoulder stiffness should be greater.

The improvement of car driving comfort is requested according to development of automobile manufacturing technology. Therefore, many experts have been studying automotive vibration of normally driving cars to improve automotive driving comfort. Vibration characteristics of a tire play an important role to judge a ride comfort ability and sound quality for a vehicle. A lots of study on the ride and the noise to reduce the vibration in the 20∼100Hz frequency range was being carried out for years. The tire impact due to the bump is the main factor of the vibration in the 20∼100Hz. This vibration is related to the harshness which perceive the displeasure or noise. In this study, we investigated the characteristics of the impact harshness due to the stiffness of the tire tread part according to change the tread compound.