Reto Ambrosini kindly mailed me the following information on this bike: "The bike is a BMW R12, they were made between 1935 and 1941.The engine is a 750 ccm, 18 hp for the model with 1 carburetor (1935-1941), 20 hp for the model with 2 (1937-1940). I don't know about the sidecar, it could be a Steib, but it's difficult to say." Mail me if you know something about the side-car. Photo: Ola Krook, Malmoe, Sweden