Patent ID: 7578329
Filing Date: 2009-08-25
Classification: B60C,Y10T

Abstract:
1. A tire for a motorcycle comprising: a tread having an outer surface which forms a tread surface, a pair of sidewalls extending almost inward in a radial direction from an end of the tread, a pair of beads extending almost inward in the radial direction from the sidewalls and a carcass laid between the beads on both sides along the insides of the tread and the sidewalls, wherein each bead has a core and an apex extending outward in the radial direction from the core, the apex has an outer layer and an inner layer which is located to the inside of the outer layer in the axial direction, the outer layer is adjacent to the inner layer and the boundary between the two layers extends inward in the radial direction from the upper end of the apex to the top surface of the bead core, a hardness of the outer layer is greater than that of the inner layer, a difference of the hardness between the outer layer and the inner layer is 15 or greater and 30 or less, a ratio of a thickness of the inner layer to that of the apex is 40% or greater and 60% or less, and a ratio of a height HA of the apex in the radial direction to a height HS in the radial direction from a bead base line BBL to an end of the tread is 40% or greater and 60% or less, the ratio of the thickness of the inner layer to that of the apex being defined by a mean calculated with a ratio of a thickness A