| 摘要 |
PURPOSE:To improve performance on ice by providing a tread face with circumferential ribs, and the ribs with numerous thin slits in the tire width direction, and specifying a ratio between the sum of the projected length to the tire width direction face of the thin slit and the surface area of the rib. CONSTITUTION:On both sides of a tread center line CL, there are provided two ribs 5 formed by three circumferential main grooves l, and the ribs 5 are provided with numerous thin slits 4 formed parallel at equal spaces apart. When the density of the thin slits is obtained by the ratio B/A between the sum B of the projected length to the face, orthogonal to the tire peripheral direction, of this thin slit 4 and the surface area A of the rib 5, it is so set that this density B/A becomes 0.15/mm. |
