Development of Low Fuel Consumption Tire for Small Motorcycles

A low fuel consumption tire with an affordable price that is applicable for small motorcycles marketed mainly for India and Southeast Asian countries was developed. Two contradicting requirements, which are reduction of the rolling resistance and retention of the wet grip performance, were satisfied by applying a method based on viscoelastic properties of the tread rubber. Regarding the composition of compound of the tread rubber, the amounts of carbon black and oil were reduced instead of using silica. In addition, a polymer having a high glass transition temperature was employed. Moreover, response to the roll motion, which is unique in motorcycles, was made satisfactory to the requirement by modifying the dynamic modulus E* of the tread rubber. With those measures, the rolling resistance was reduced by more than 15% to conventional tires while maintaining the basic performances such as tire grip and stability in maneuvering.