For more than a century, the basic configuration of the tire has not changed. It is still the same combination of a circular rubber containment chamber linked to a rim and filled with air. Of course, through the years, the tire has become wider, safer, quieter and long lasting. Also, many of them are of the "run flat" type, allowing the driver to keep-on motoring for sixty or seventy kilometers before having to repair the puncture.
But if tire engineers are quite satisfied with the level of performance and durability of modern tires, they worked very hard in the past decade to develop a tire that could offer not only "run flat" capabilities, but also a higher level of performance than most tires on the market.
Researchers at Michelin think they have found the answer with the PAX System. As its name implies, it is not only new tire technology, but a new tire and wheel combination. All the other tires on the market use interior air pressure to keep the bead in contact with the rim. "Run flat" tires have very rigid sidewalls that prevent deformation of the bead and keep it in contact with the rim and thus allow the driver to be able to drive to the next service station.
With the PAX System, the sidewalls are linked vertically to the rim. They remain in contact with it through the use of a plastic sealing ring, and there is even a lubricating system to prevent overheating if loss of pressure occurs. These sidewalls are also lower to obtain better performances, but without any compromise in comfort. And as the thread is more stable, the noise level is lower while the durability and lateral grip are improved.