Pneumatic tire for two-wheeled motor vehicle

Abstract

A pneumatic tire for a two-wheeled motor vehicle has a tread section (1) including one or more layers of tread rubber (7), a pair of side wall sections (2) extending radially inward so as to continue to opposite sides of the tread section (1), and bead sections (3) continuing to the radially inner peripheral sides of the side wall sections (2). A ground contact region of the tread section (1) is made up of five regions that are a center region (8) including a tire's equatorial plane (E), a pair of shoulder regions (9) including tread's ground contact ends, and a pair of intermediate regions (10) each located between the center region (8) and a shoulder region (9). The 100% modulus at a room temperature (25 DEG C) of intermediate tread rubber (9a) placed in the entire intermediate region (10) is set greater than both the 100% modulus of center tread rubber (7b) placed in the entire center region (8) and the 100% modulus of shoulder tread rubber placed in the entire shoulder regions (9). The negative ratio of the tread's ground contact region is increased from the shoulder regions (9) toward the center region (8). The tire can exhibit excellent wet performance without sacrificing dry performance and always enables stable driving of a two-wheeled motor vehicle.

Description

technical field [0001] The present invention relates to a pneumatic tire for a two-wheeled motor vehicle, and particularly proposes a technique for enabling the tire to run stably on dry or wet roads. Background technique [0002] Unlike tires for four-wheeled vehicles, such as buses and trucks, which are mainly given a slip angle to achieve turning, tires for two-wheeled vehicles need to be given the tires relative to the road surface on which the tires run when turning. The camber angle of the slope. Therefore, in a motorcycle tire, the ground contact region of the tread portion is different when going straight and when turning. [0003] Specifically, in tires for motorcycles, the central region of the tread portion including the equatorial plane of the tire is brought into contact with the road surface when running straight, so as to exert a driving force or braking force on the road surface, and is used when turning. Each shoulder region including the ground contact en...

AI Technical Summary

Problems solved by technology

[0007] However, in the pneumatic tire for motorcycles disclosed in Japanese Patent Laid-Open No. 2006-273240, although the durability at relatively high speeds achieved by the central region and the grip performance and stability at the time of cornering achieved by the shoulder regions Both are enhanced, but the application of driving force or braking on the road surface needs to be achieved by each intermediate zone extending between the central zone and the shoulder zones and in contact with the road surface especially when accelerating to exit a turn. The results are still unsatisfactory in terms of dynamics and the generation of lateral forces against centrifugal forces

[0008] In addition, in this pneumatic tire for motorcycles, there is a concern that problems such as uneven wear may occur in the middle region and its vicinity, especially due to running when turning.

[0009] In addition, in the case where two types of tread compounds whose ratios of loss tangent to dynamic elastic modulus are significantly different from each other are used for the central region and the shoulder region, respectively, when the camber angle increases or decreases, the different types of tread rubber The tread rubber is in contact with the ground sequentially or simultaneously, so as the camber angle changes, the ground contact performance of the tread rubber changes significantly, and may significantly affect the driving stability when cornering

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