Abstract: A pneumatic tire is provided in the tread portion with tread blocks capable of improving running performance on rough terrain, wherein a degree of circularity Eb of a contour shape of a section of the tread block taken parallel with the top surface of the tread block at a block foot position is more than a degree of circularity Et of a contour shape of the top surface. The degree of circularity is: 4×pi×S/L2, wherein, pi is the circumference ratio, S is an area of the contour shape, and L is a circumferential length of the contour shape. The block foot position is defined as being spaced apart from a tread bottom by 10% of a height of the tread block from the tread bottom.

Abstract: A radial motorcycle tire comprises a tread portion with a pair of tread edges, a pair of sidewall portions, a pair of bead portions each with a bead core therein, and a band disposed in the tread portion and composed of windings of at least one cord wound at an angle of not more than 5 degrees with respect to the tire equator. The tread portion is provided radially inside the band with at least two layers of cords comprising a radially outermost first layer and a radially inner second layer next to the first layer, wherein with respect to the tire equator, the cords of the first layer are inclined to a direction at an angle of from 65 to 90 degrees, and the cords of the second layer are inclined to the same direction as the first layer at an angle of from 65 to 90 degrees.

Abstract: A pneumatic tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions, a pair of bead cores each being disposed in the bead portion, the bead core comprising an annular core extending in the tire circumferential direction and a sheath including a plurality of sheath wires each extending helically around the annular core, a carcass comprising a carcass ply extending between the bead portions and turned up around the bead core in each bead portion, wherein one of the bead cores is reverse to the other bead core with respect to the helical direction of the sheath wire.

Abstract: A radial motorcycle tire comprises a tread portion with a pair of tread edges, a pair of sidewall portions, a pair of bead portions each with a bead core therein, and a band disposed in the tread portion and composed of windings of at least one cord wound at an angle of not more than 5 degrees with respect to the tire equator. The tread portion is provided radially inside the band with at least two layers of cords comprising a radially outermost first layer and a radially inner second layer next to the first layer, wherein with respect to the tire equator, the cords of the first layer are inclined to a direction at an angle of from 65 to 90 degrees, and the cords of the second layer are inclined to the same direction as the first layer at an angle of from 65 to 90 degrees.

Abstract: A pneumatic tire for passenger cars which is improved in harshness noise without deteriorating the steering stability is disclosed, wherein a harshness factor HF is set in the range of from 3.2 to 3.5, the harshness factor HF is: HF=−0.133×(R1/100)+0.245×(R1/R2)−0.183×(Kv/10)+3.898 R1 is a radius of curvature (in mm) of a crown part of the tread profile, R2 is a radius of curvature (in mm) of shoulder parts of the tread profile, and Kv is the vertical spring constant in kN/mm of the tire.

Abstract: A radial tire which mitigates reactions when running across protrusions to thereby avoid damage to the vehicle. The tire prevents rim touch, an indirect contact of the inner face of the tread portion with a flange of the rim or a direct contact of the tread portion with the bead portion. The tire has sidewall portions which are bulged-out to satisfy certain equations. An increase in sidewall thickness and carcass rigidity is avoided with the radial tire.

Abstract: A radial tire comprises a carcass, a tread thereon, a breaker therebetween, bead cores, and rubber bead apexes, and is characterized in that:(a) the clip width (C1) is smaller than the rim width (C2) of a normal rim for a tire;(b) the carcass (6), in a state of the tire mounted on the normal rim and inflated to a standard pressure, has:an outwardly bulging outer part (21) between the largest width point (D) and a radially outer second point (E2),an outwardly bulging middle part (22) between the largest width point (D) and a inflexion point (F), andan inwardly bulging inner part (23) between the inflexion point (F) and a radially inner first point (E1);(c) the radial height (H2) of the largest width point (D) from the first point (E1) is 50-40% of the height (H1) of the second point (E2);(d) the axial distance (L1) between the largest width point (D) and a third line (X3) is 28-33% of the height (H1); and(e) the axial distance (L2) between the inflexion point (F) and the third line (X3) is 70-55% of the distan