A pneumatic tire has a plurality of circumferential main grooves extending in the tire circumferential direction, a plurality of lug grooves extending in the tire width direction, and a plurality of blocks partitioned by the circumferential main grooves and the lug grooves. Also, the block has a bent groove having a bent shape that is convex in one direction and that extends in the tire circumferential direction dividing the block into two in the tire width direction. Also, the blocks that are adjacent to each other in the tire circumferential direction are disposed such that the bend directions of the bent grooves are alternately reversed.

A method is disclosed for analyzing the rolling of a rotating body that will make it possible to simultaneously achieve reduction in computational cost and attainment of adequate analytic precision. The method includes: a step (S100, S101) in which a structural model is acquired; a step (S103) in, which a region Ar1 on a rotating body T at which finely divided computational mesh cells are established is made to come in contact with the ground, and rolling analysis processing is performed in which rolling is made to occur in an amount that is an angle corresponding to N minimum units (where N is a natural number not less than 1); and a step (S105) in which mapping processing is performed in which physical quantities at computational mesh cells as they exist following the rolling analysis processing are copied to corresponding computational mesh cells at a rolling start time.

A pneumatic tire can improve the heat dissipation effect in the tread portion while guaranteeing land portion rigidity and can also suppress degradation of the heat dissipation effect. The pneumatic tire includes a narrow groove (10) on a tread surface (1), extending at an inclination to the tire circumferential direction, the groove width (W1) being smaller than the groove depth (D1), an air inflow part (11) opening to the tread surface (1) and formed on at least one of the groove walls (10c) of the narrow groove (10) that face each other in the tire circumferential direction, and a wear prevention portion (12) formed by a protrusion or concavity on a groove wall (10c) that faces the other groove wall (10c) on which the air inflow part (11) is formed or on the tread surface (1) connecting to the groove wall (10c) that faces the other groove wall (10c).

This pneumatic tire (1) has a first profile (PL1) wherein land sections (3) located further inside in the tire width direction than right and left outermost circumferential main grooves (2) protrudes outward in the tire radius direction. In addition, the pneumatic tire has a second profile (PL2) wherein shoulder land sections (3) protrudes inward in the tire radius direction within a ground contact surface. The distance d in the tire radial direction from a line extending from the first profile (PL1) to the second profile (PL2) within the ground contact surface increases toward the outer side in the tire width direction. In addition, the distance (Gcc) from a tread profile (first profile (PL1)) within a tire equatorial plane (CL) to a tire inner circumferential surface and the distance (Gsh) from a tread end (P) to the tire inner circumferential surface have the relationship of 1.10Gsh/Gcc.

A pneumatic tire includes a narrow groove on a tread surface, inclined from the tire circumferential direction, groove width being smaller than groove depth, and an air inflow part opening to the tread surface and formed on one of the opposing groove walls. At least one end of the narrow groove is a terminal end. The air inflow part is disposed at the terminal end of the narrow groove, and in a development plan view of the tread surface, XOY is an acute angle, where O is an intersection between a widthwise center line of the air inflow part and a groove widthwise center line of the narrow groove, X is a terminal endpoint of the air inflow part along the widthwise center line of the air inflow part, and Y is a lengthwise center point of the narrow groove along the groove widthwise center line.

A pneumatic tire can have a tread portion. A sponge-like sound absorbing member can be on an inner surface of the tread portion. The sound absorbing member can have an outer peripheral surface facing outward in a tire radial direction. A plurality of grooves, and a plurality of land portions separated from each other by the plurality of grooves, can be formed in the outer peripheral surface. Each of the plurality of land portions can be attached to the inner surface continuously along a longitudinal direction of the groove.

A pneumatic tire includes a center land portion, intermediate land portions, and shoulder land portions each with sipes arranged at intervals in a circumferential direction. Center land sipes have a widened portion with a wide groove width at one end. Shoulder land sipes extend from the outer side of a ground contact end in a lateral direction toward an outer main groove. The orientation of the center and shoulder land sipes with respect to the circumferential direction is opposite to the orientation of intermediate land sipes. Respective inclination angles ?.sub.CE, ?.sub.MD, ?.sub.SH of the center, intermediate and shoulder land sipes satisfy ?.sub.CE<?.sub.MD<?.sub.SH<90?, an end of the intermediate land sipe on the side of the inner main groove is between ends of the center land sipes, and at any position on the entire circumference at least one center or intermediate land sipe is present on a meridian.

A two-wheel vehicle tire has a tread portion. The tread portion includes a plurality of grooves. The grooves include crown grooves arranged on a tire equator, middle grooves, and shoulder grooves. Each of the crown grooves is bent in a V-shape so as to be convex to one side in a tire circumferential direction. Each of the grooves has the shortest distance from 5% to 30% of a tread development half width between another one of the grooves immediately adjacent to the each of the grooves.

A pneumatic tire includes a tread portion provided with at least one block and a groove adjacent the at least one block. The at least one block includes a main portion with a ground contact surface for coming into contact with a ground and an auxiliary portion located radially inward of the ground contact surface of the main portion and protruding laterally from the main portion. The auxiliary portion includes a first portion extending along in a longitudinal direction of the groove and at least two second portions located radially outward of the first portion and arranged separately from one another in the longitudinal direction of the groove.

Provided is a pneumatic tire being improved in heat dissipation effect in the tread portion while being ensured in rigidity of the land portion. A narrow groove (9) is formed on a tread surface (1), the narrow groove extending in a direction inclined relative to the tire circumferential direction and having a groove width (W1) and a groove depth (D1), the groove width (W1) being smaller than the groove depth (D1). The narrow groove (9) opens at both ends thereof to the outside of the land portion. An air inflow part (10) is formed on at least one of the groove walls (9c) of the narrow groove (9), the groove walls facing each other in the tire circumferential direction, where the narrow groove (9) has a maximum depth (D1) and the air inflow part (10) has a maximum depth (D2), the D1 and the D2 satisfying 5<D1/D215.