Abstract: A pneumatic rubber tire having a tread comprised of a blend of cis-1,4 polyisoprene rubber and a medium vinyl polybutadiene rubber cured with an excess of sulfur. Said tire has been found to be useful as an aircraft tire having tread of enhanced durability.

Abstract: Improved green strength of elastomers made from monomers selected from the class consisting of at least one conjugated diene having from 4 to 10 carbon atoms, olefins having from 2 to 14 carbon atoms along with a diene having from 4 to 6 carbon atoms, and combinations thereof, is achieved by adding an amount of a polydimethylbutadiene compound to form a blend having a glass transition temperature of from about 0.degree. C to about -100.degree. C. The polydimethylbutadiene compound may be merely the homopolymer of dimetylbutadiene, the copolymer, the terpolymer or the tetrapolymer of dimethylbutadiene in various combinations with monomers such as butadiene, isoprene, piperylene, acrylonitrile, vinylidene chloride, vinyl pyridine, methacrylic acid and vinyl substituted aromatic compounds.