At the International Bicycle and Motorcycle Show (IFMA) in 1978, BMW sprang a surprise with an entirely new "small" ("kleine") series. The BMW R 45 and R 65 models were intended to plug the gap in the range of entry-level models, in other words the popular 500 and 600 cc capacity class. The engine and the double-loop frame had been redesigned. The BMW R 45 with displacement of 473 cc was supplied as a 27 hp and 35 hp version. The 27 hp version benefited from its favourable insurance class and swiftly advanced to become the bestselling model in the BMW motorcycle range. In 1979, it was in fact the biggest selling motorcycle in Germany.