BMWR4 1932 - 1937

　　Introduced in 1932, the BMW R4 was intended to close the gap between the R2 and the 750cc models, such as the R11 and R16. Government agencies, such as the military and the police, ordered several thousand units of the R4, which was a dependable utility motorcycle.

　　The classic machine came with standard features such as wire-spoked wheels, full fenders, a hard-tail rear suspension with a sprung seat, a parallelogram front suspension, a large headlight, a rear luggage rack, and an exhaust system with a large-diameter muffler.

　　Starting with the engine, the BMW R4 had a 398cc single-cylinder four-stroke air-cooled unit that developed a power of 12 hp at 4,000 rpm. The power from the engine was transferred to the rear wheel through a shaft and a three-speed manual transmission.

　　The model was packed with a double-loop pressed steel frame, on which was mounted the front suspension consisted of a fork with leaf springs mounted above the fender. The rear suspension consisted of two springs fitted under the seat while the wheel was directly mounted to the frame.

　　The braking power of the model was handled by a 180 mm drum on the front wheel and a 180 mm drum on the rear wheel.

　　With a curb weight of 137 kg (302 lbs), the 1932 BMW R4 had a top speed of 100 kph (62 mph).