Tire rubber composition and pneumatic tire

A rubber composition for tires, comprising

• a diene rubber A modified with an acrylamide compound represented by Formula (I):
• wherein R1 represents hydrogen or a methyl group;
• R2 and R3 each represent an alkyl group;
• and n represents an integer, and
• a diene rubber B modified with either a combination of a silicon or tin compound represented by Formula (II) and a modifying compound represented by Formula (III) or with a modifying compound represented by Formula (III):
• RaMXb (II)
• wherein R represents an alkyl, alkenyl, cycloalkenyl, or aromatic hydrocarbon group;
• M represents silicon or tin;
• X represents a halogen;
• a represents an integer of 0 to 2;
• and b represents an integer of 2 to 4,
• wherein R4 to R6 are the same as or different from one another, each representing a C1 to C8 alkyl group;
• R7 to R12 are the same as or different from one another, each representing a C1 to C8 alkoxy or alkyl group;
• and p to r are the same as or different from one another, each representing an integer of 1 to 8, the combined modified diene rubbers A and B having a weight average molecular weight of 300,000 to 1,400,000, and
• the rubber composition further comprising silica having a CTAB specific surface area of 180 m2/g or more and a BET specific surface area of 185 m2/g or more.