Brabham was considered a technically conservative team in the 1960s, chiefly because it persevered with traditional spaceframe cars long after Lotus introduced lighter, stiffer monocoque chassis to Formula One in 1962. Chief designer Tauranac reasoned that monocoques of the time were not usefully stiffer than well designed spaceframe chassis, and were harder to repair and less suitable for MRD's customers. His "old fashioned" cars won the Brabham team the 1966 and 1967 championships, and were competitive in Formula One until rule changes forced a move to monocoques in 1970.