Motorcycle specifications YamahaRD 500 LC 1984 Yamaha showcases its technological expertise

In 1984, Yamaha was recovering from a difficult period, but on the strength of the extraordinary success of its RD/LC350, the brand decided to go all out and take its racing image even further with the RD 500 LC, a stunning replica of Kenny Roberts' world-champion bike.

an exception

the 500 RD/LC promises to be the most sophisticated production sports machine ever built. Modelled on racing machines, its engine is a veritable "gas factory", with a V-twin crankshaft, liquid cooling, rotary exhaust valves and looks to make Grand Prix enthusiasts swoon. Although it's a far cry from the brutality of the old three-cylinder Kawasaki, the engine only really gets going at 6,500 rpm. With a remarkable power-to-weight ratio (221 kg when fully loaded), the RD/LC 500 makes a mockery of many a 750 Sport, and the performance is there: 87 bhp, over 220 km/h and 12.2 s at 400 m from a standing start. The chassis, on the other hand, had a little trouble keeping up, and Yamaha's first aluminum frame, reserved for Japan, was rejected by Europe, which had to make do with steel tubing, cheaper but much stiffer.

kenny Roberts almost replica

for reasons of cost and space, the engine design was ultimately quite different from that of the world champion bike. The rotating-disc intake system was not adopted, and lack of space led to the definition of a curious intake system, with valves in the crankcase for the lower cylinders and valves directly in the cylinders for the upper block.

François-Marie Dumas - Image credits: Yamaha