1969 Chevrolet Corvette ZLI: Radial Tires
Radial tires — in which the cord plies that make up the structure are perpendicular to the tire's rotation — were invented back in 1915 and had entered production in Europe with Michelin by 1946. But in America, where Goodyear ruled the tire market, old-style bias-ply tires ruled into the 1970s. B.F. Goodrich, a tiny company compared to Goodyear, was the first to manufacture radials in America, and needed to carve out its market niche. It did that by racing its Lifesaver Radial T/A street tires against purpose-made racing-bias-ply tires in road racing. After a few tentative events in smaller sedans, the B.F. Goodrich went big in 1971 when it asked three-time Le Mans competitor John Greenwood to campaign his Corvette in an endurance race at Michigan International Speedway. He won the race, and BFG shouted about it as loudly as its marketing budget would allow. By 1972 Greenwood had a two-car team using vehicles cobbled together from 1969 Corvette roadsters powered by the legendary all-aluminum ZL-1 big-block V8. Soon Goodyear was responding with racing street radials of its own, and by the mid-'70s, the bias-ply tire was essentially dead in the market.