The Honda XBR 500 is a 500cc Japanese sports motorcycle launched by Honda in 1985 and in response to the Yamaha SR500. It is powered by a single-cylinder four-valve engine with the valves arranged radially relative to the geometric centre of the hemispherical combustion chamber - (the Radial Four Valve Combustion Chamber, or RFVC) and actuated via intermediate sub-rockers. Displacing 498 cc (30.4 cu in) and producing 27 or 44 hp, the engine, having its origins in the Honda XR series off-road models, features a dry sump, the oil being stored in a separate tank below the seat. The steel-braided hoses connecting the oil tank to the engine (clearly visible at the right-hand side of the motorcycle) are a strong visual element.