Motorcycle Tire Tread Composition for Braking and Cornering Grip

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Motorcycle tires lack optimal performance during braking and cornering, particularly in race conditions, due to differing rubber properties in the center and shoulder regions.

Innovation Solution

A motorcycle tire design with a tread portion divided into at least three parts, featuring a center rubber and shoulder rubbers with specific silica content ratios and 300% modulus ratios, and grooves extending between them to enhance braking and cornering performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the center rubber and shoulder rubber are designed with different rubber physical properties to optimize performance for straight running and turning respectively, then the braking performance and cornering performance are improved, but the tire structure becomes more complex

Engineering Contradiction:
Improvebraking performance and cornering performanceVSAvoidtire structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The tread rubber is divided into at least three parts in the tire width direction: a center rubber at the central part and shoulder rubbers on opposite sides. This segmentation allows each region to have optimized properties for its specific function (straight running vs. cornering), resolving the contradiction by making the complexity necessary for performance optimization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The center rubber and shoulder rubbers are given different rubber physical properties tailored to their respective functions. The center rubber is optimized for straight running contact, while the shoulder rubbers are optimized for cornering contact. This local differentiation achieves high reliability in both operating conditions without requiring overly complex overall structure.

Inventive Principle:
Principle #3Local quality

2Reliability

If silica content in shoulder rubbers is increased to improve cornering responsiveness, then cornering performance is enhanced, but the overall tire balance and heat distribution may be adversely affected

Engineering Contradiction:
Improvecornering responsivenessVSAvoidtire heat distribution and structural balance
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The silica content in the shoulder rubbers is specifically controlled within the range of 60-120 parts by mass per 100 parts by mass of rubber component. This parameter optimization enhances cornering responsiveness while maintaining adequate heat resistance and structural balance. The silica amount is carefully tuned to achieve the desired performance without causing excessive heat generation or compromising overall tire stability.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4578664A1Motorcycle tire
Publication Date: 2025.07.02 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4578664A1 patent drawingFigure 1
  • EP4578664A1 patent drawingFigure 2~3
  • EP4578664A1 patent drawing

AI summary

Provided is a motorcycle tire having excellent running performances including braking performance upon entering a corner and cornering performance. The motorcycle tire includes a tread portion (2) including a tread rubber that is divided into at least three parts in a tire width direction, the tread rubber including a center rubber (9A) at its central part in the tire width direction and shoulder rubbers (9B) respectively on opposite sides of the center rubber in the tire width direction, the tread rubber having a groove extending on both the center rubber and at least one of the shoulder rubbers, the center rubber and the shoulder rubbers each containing silica in an amount of 70 parts by mass or more per 100 parts by mass of a rubber component therein, the amount Si(S) of the silica in the shoulder rubbers and the amount Si(C) of the silica in the center rubber giving a ratio (Si(S)/Si(C)) of 0.80 or higher and 0.95 or lower, the shoulder rubbers having a 300% modulus M300(S) and the center rubber having a 300% modulus M300(C), the M300(S) and the M300(C) giving a ratio (M300(S)/M300(C)) of 1.15 or higher and 1.50 or lower.