It is also part of the tire does not touch the ground at the street car to run is. Duty to prevent harm to the project, and as part of flexible (Flexible) most of the tires.
The outer part of the tire that touches the road where the car is not running. Act to prevent harm to the casing and a flexible rubber part (Flexible) most of the tires.
As the outer part of the rubber does not touch the ground to run. The danger with rubber and rubber part structure is flexible (Flexible) most of the rubber.