The present invention provides a rubber composition, which has improved
gripping performance that is required in a competition tire, high
hardness and high stiffness. Specifically, the present invention provides
a rubber composition comprising 10 to 100 parts by weight of carbon black
having nitrogen-adsorbing specific surface area of 160 to 300 m.sup.2/g,
and 15 to 70 parts by weight of an oil, based on 100 parts by weight of a
rubber component comprising 20 to 95% by weight of a styrene butadiene
copolymer rubber having styrene content of at least 30% and vinyl content
of at least 30% and 5 to 80% by weight of butadiene rubber, and silica in
an amount of 20 to 100% by weight of the carbon black; wherein the total
amount of the carbon black and the silica is 20 to 120 parts by weight.