Judging from viewpoint of automotive safety and more space by eliminating a spare tire, the development of the run-flat tires is important.
Many problems relating to weight increase and usability had to be solved in the course of the development of such tires.
The “ N ” type run-flat tire, described in this paper, has a simple structure with reinforced side walls and additional beads to fit the rim flanges.
Though this tire system brought about a small amount of weight increase, it needs no special part, therefore the conventional road wheels, air valves and tire changers may be used.
We have tested and evaluated this tire system equipped with passenger cars as well as on the test machines. Especially vehicle dynamics such as steering, stability and so forth were tested.
The test results indicated that this tire system is practical enough.