Patent ID: 8469071

Claim:
A run flat tire comprising at least one layer of a carcass layer provided around bead cores embedded in a left-right pair of bead portions and folded over from a tire inner side toward a tire outer side so as to envelop bead fillers that are disposed on an outer circumferential side of the bead cores, wherein a plurality of belt layers is disposed on an inner circumferential side of a tread portion, a belt cover layer formed from organic fiber cords is disposed on the outer circumferential side of the belt layers, and a side reinforcing layer having a falcated cross-section is disposed between the carcass layer and an inner liner layer in a side wall portion; wherein a relationship between a tire cross-sectional height SHi on an inner side in the tire radial direction and a tire cross-sectional height SHo on an outer side in the tire radial direction, demarcated by a maximum tire width position when the run flat tire is assembled on a JATMA regulation standard rim and inflated to an air pressure of 180 kPa, is 0.7<SHi/SHo<0.9; an intersection P of a line tangent to an intersection S of a straight line Q in a tire axial direction passing through a midpoint of the tire cross-sectional height SHo and a tire outer wall and an external tire diameter line Z is positioned more to a tire equatorial plane side than a region R that corresponds to 90% of a rim width HRW of the standard rim having the tire equatorial plane as a center; an angle α of a straight line connecting, in the tread surface, a point O on the tire equatorial plane and a point R′ on a shoulder side corresponding to 110% of a tire ground contact width TW having the tire equatorial plane as a center, with respect to the tire axial direction, is from 7.5 to 10°; the outer peripheral edge of the bead filler is positioned more to the inner side in the tire radial direction than a line normal to a rim line on an outer wall surface of the bead portion; when Ga is a rubber thickness taken on a line normal to the rim line between the carcass layer and an outer wall surface of the side wall portion, and Gb is a maximum rubber thickness taken on a line normal to the carcass layer between the carcass layer and the outer wall surface of the side wall portion, a relationship between Ga and Gb is 0.65 Gb<Ga<0.85 Gb; and when Gc is a rubber thickness taken on a line normal to the rim line between the carcass layer and a tire inner wall surface, a relationship between Gc and Ga is 0.85 Ga<Gc<1.00 Ga.