Dual layer tire tread

A method of forming a tread for a racing tire, comprising:

• forming a first rubber composition, the first rubber composition comprising 70 to 92 phr of a solution-polymerized styrene butadiene rubber, at least one of an isoprene rubber and a polybutadiene rubber, 50 to 160 phr of silica, at least 10 phr of a resin, and 0 to 25 phr of carbon black;
• forming a second rubber composition, the second rubber composition comprising 70 to 100 phr of a polyisoprene rubber, 5 to 25 phr of silica, and 20 to 60 phr of carbon black;
• forming a first layer from the first rubber composition such that the first layer defines a first portion of a road-contacting surface of the tread;
• forming a second layer from the second rubber composition, such that the second layer defines a second portion the road-contacting surface of the tread and is partially covered by the first layer;
• and
• curing the first and second layers to form the tire tread.

A racing tire comprising a tread, the tread comprising:

• a first layer formed of a first rubber composition, the first layer defining a first portion of a road-contacting surface of the tread;
• and
• a second layer formed of a second rubber composition, the second layer defining a second portion the road-contacting surface of the tread and being partially covered by the first layer;
• the first rubber composition comprising:
• 70 to 92 phr of a solution-polymerized styrene butadiene rubber,
• 0 to 30 phr of a polyisoprene rubber,
• 0 to 30 phr of a polybutadiene rubber,
• 50 to 160 phr of silica,
• 0 to 25 phr of carbon black,
• 2 to 70 phr of processing oil,
• 10 to 70 phr of resin,
• 2 to 20 phr of an organosilane coupling agent, and
• a cure package including a sulfur-based curing agent, zinc oxide,
• a fatty acid, and an accelerator;
• the second rubber composition comprising:
• 70 to 100 phr of a polyisoprene rubber,
• 30 to 60 phr of carbon black,
• no more than 5 phr of resin,
• 1 to 10 phr of processing oil, and
• a cure package including a sulfur-based curing agent, zinc oxide,
• a fatty acid, and an accelerator.