Honda RC112

The Honda RC112 is a 50 cc air-cooled DOHC inline-twin racing motorcycle that Honda manufactured in 1962, the world's first 50 cc DOHC twin racer. It competed in only one race, the All Japan Championship at the Suzuka Circuit, which Tommy Robb won on it. Honda had entered the new 50 cc world championship that year, but its single-cylinder RC110 was not as quick as the Suzuki and Kreidler two-strokes, and even the updated RC111 was not competitive at the Isle of Man TT. Soon after the TT Honda began developing the twin, with engineer Shoichiro Irimajiri playing a major part, and a large-valve 2RC112 followed. Neither was developed enough for the world championship, but the RC112 was ready for the inaugural race at Honda's newly finished Suzuka circuit, where Robb later said he thought the twin far better.