Abstract: A pneumatic tires includes a tread, a pair of sidewalls, and a pair of bead portions that are arranged at intervals wider than a rim width of a corresponding regular rim in a non-rim-assembled state. Each of the pair of the bead portions includes a bead base at an inner diameter side end, a bead heel, and a bead back surface extending from an outer diameter side end of the bead heel, to the outer diameter side. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the width direction. In a rim-assembled state, the bead back surface is in close contact with substantially the entire surface of a radial portion of a rim flange of a regular rim.

Abstract: A pneumatic tire includes a pair of bead portions that are arranged at intervals wider than a regular rim width in a non-rim-assembled state. The bead portion includes a rim protector, a bead base, a bead heel, and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the tire width direction. The bead back surface has a second curved portion constituting a deepest portion of the recess and a third curved portion extending inward in the tire width direction from the rim protector. When a height of the deepest portion is H2, a height H8 of a virtual intersection of a curve obtained by extending the second curved portion and a curve obtained by extending the third curved portion is larger than 1.5 times H10 and smaller than 3.0 times H10.

Abstract: A pneumatic tire includes a pair of bead portions that are arranged at intervals wider than a regular rim width in a non-rim-assembled state. The bead portions includes a bead base, a bead heel, and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the tire width, a rim flange of the regular rim has a radial portion and a curved portion. In a rim-assembled state, the bead back surface is in close contact with substantially an entire surface of the radial portion. A tire radial distance from an apex of the curved portion to an outer surface of the bead back surface is set so that the outer surface of the bead back surface is separated from the curved portion even in a state where a load is input.

Abstract: A pneumatic tires include a tread, a pair of sidewalls, and a pair of bead portions that are arranged at intervals wider than a rim width of a corresponding regular rim in a non-rim-assembled state. Each of the pair of the bead portions includes a bead heel and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess. The bead back surface has a recess R portion having an arc shape. A center of curvature of the recess R portion is located in a radial range between a radial position that is 2.0 mm to the inner side in the tire radial direction and a radial position that is 9.0 mm to the outer side in the tire radial direction with reference to an outer end surface of a bead core in the tire radial direction.

Abstract: A pneumatic tires includes a tread, a pair of sidewalls, and a pair of bead portions that are arranged at intervals wider than a rim width of a corresponding regular rim in a non-rim-assembled state. Each of the pair of the bead portions includes a bead base at an inner diameter side end, a bead heel, and a bead back surface extending from an outer diameter side end of the bead heel, to the outer diameter side. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the width direction. In a rim-assembled state, the bead back surface is in close contact with substantially the entire surface of a radial portion of a rim flange of a regular rim.

Abstract: A pneumatic tires include a tread, a pair of sidewalls, and a pair of bead portions that are arranged at intervals wider than a rim width of a corresponding regular rim in a non-rim-assembled state. Each of the pair of bead portions includes a bead heel that curves outwards toward the outer side in the width direction and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess. The bead heel 35 includes a heel R portion having an arc shape. The bead back surface includes a recess R portion having an arc shape. A radius of curvature of the recess R portion is equal to or larger than a radius of curvature.

Abstract: A pneumatic tire includes a pair of bead portions that are arranged at intervals wider than a regular rim width in a non-rim-assembled state. The bead portion includes a rim protector, a bead base, a bead heel, and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the tire width direction. The bead back surface has a second curved portion constituting a deepest portion of the recess and a third curved portion extending inward in the tire width direction from the rim protector. When a height of the deepest portion is H2, a height H8 of a virtual intersection of a curve obtained by extending the second curved portion and a curve obtained by extending the third curved portion is larger than 1.5 times H10 and smaller than 3.0 times H10.

Abstract: A pneumatic tire includes a tread, a pair of sidewalls, and a pair of bead portions. Each of a pair of the bead portions includes a bead base, a bead heel, and a bead back surface. In a non-rim-assembled state, the bead back surface is formed with a recess, the bead base is formed to be inclined inward in the tire radial direction toward the inner side in the tire width direction, the bead back surface has a recess R portion and a tangential portion that connects the bead heel and the recess R portion, and in the non-rim-assembled state, a base portion inclination angle of the bead base with respect to a tire axial direction is set to be larger than a tangential portion inclination angle of the tangential portion with respect to the tire radial direction.

Abstract: A tire distortion detection method includes a first step of forming a portion to be detected on a surface of an inner liner, a second step of detecting the portion to be detected in any two states from a formation of a product tire from a tire component including the inner liner to a change for a load condition on the product tire, and a third step of comparing positions of the portions to be detected in the two states obtained in the second step.

Abstract: A vehicle traveling condition evaluation method comprising: dividing stored map information into a plurality of sectioned areas; associating position information indicating a position of a vehicle with traveling information indicating traveling of the vehicle; storing the information obtained in the associating; calculating an index value of the traveling information for each of the plurality of sectioned area based on the information accumulated in the storing; and displaying the index value calculated in the calculating as traveling severity in an identifiable manner on a map displayed on a screen for each of the plurality of sectioned areas.

Abstract: In a rubber friction test method of measuring a friction coefficient of a rubber test specimen by relatively moving the rubber test specimen and a test road surface in a state in which the rubber test specimen is pressed to the test road surface by applying a load, the method includes a step of measuring a resistance force acting on the rubber test specimen while accelerating or decelerating a speed of the relative movement, and a step of calculating the friction coefficient based on the applied load and the measured resistance force.

Abstract: A rubber adhesion test method in accordance with the present embodiment has step(s) in which rubber test member is pressed against prescribed road surface for a prescribed contact time and is thereafter pulled away therefrom, the pulling force acting thereon when this is pulled away therefrom being measured, this being performed a plurality of times, with the contact time being varied each time, and step(s) in which a relational expression relating adhesive force and contact time in correspondence to pulling force is derived based on the results of the plurality of measurements.

Abstract: A tire distortion detection method includes a first step of forming a portion to be detected on a surface of an inner liner, a second step of detecting the portion to be detected in any two states from a formation of a product tire from a tire component including the inner liner to a change for a load condition on the product tire, and a third step of comparing positions of the portions to be detected in the two states obtained in the second step.

Abstract: A tire distortion detection method includes a first step of forming a metallic portion to be detected in a plurality of locations of at least one of tire components, a second step of detecting the portion to be detected in any two states including before and after a manufacturing process for obtaining a product tire from a plurality of tire components including the above tire components, and a third step of comparing positions of the respective portions to be detected in the two states obtained in the second step.

Abstract: A tire load application device includes a support base having a support surface against which part of a tread surface of a tire abuts, a support member configured to support an inner circumferential side of the tire and protrude toward both end sides in a tire axial center direction, and a longitudinal load application mechanism configured to apply a load to both end portions of the support member and press the tire toward the support surface.

Abstract: A device for measuring a tire ground state includes a traveling surface, a tire drive unit, a measuring sheet, a protection sheet which covers the measuring sheet, and a backward and forward tensile force application mechanism. A space conducting the protection sheet to a portion below the traveling surface is formed in at least one of a delay side and an advance side of the measuring sheet in the tire forward traveling direction on the traveling surface. The backward and forward tensile force application mechanism has a roller which is arranged within the space, and is structured such as to pull at least one end of the protection sheet fixed to the roller in the tire forward traveling direction from the below of the traveling surface by rotating the roller.

Abstract: In a rubber friction test method of measuring a friction coefficient of a rubber test specimen by relatively moving the rubber test specimen and a test road surface in a state in which the rubber test specimen is pressed to the test road surface by applying a load, the method includes a step of measuring a resistance force acting on the rubber test specimen while accelerating or decelerating a speed of the relative movement, and a step of calculating the friction coefficient based on the applied load and the measured resistance force.