BMW 1955 R25/3 245 cc OHV single frame & engine # 314862 Built to the same exemplary standards as the Bavarian company’s famous flat-twins, the single-cylinder BMW first appears in 1925 as the 247 cc R39. Throughout the twenties and thirties singles are brought out in various capacities, ranging from 198 cc to 398 cc. For some years after the war Allied restrictions prevent German companies to produce machines of greater capacity than 250cc, so BMW’s first postwar model is a 247 cc single, the R ...