BMW merged with Bayerische Flugzeugwerke in 1922, and the BFw Helios became the starting point for the first BMW motorcycle. Released in 1923, the BMW R 32 used a flat-twin petrol engine, which was longitudinally-mounted to eliminate the cooling problems of the transversely mounted engine in the Helios. This engine with , resulting in a top speed of . At a time when many motorcycle manufacturers used total-loss oiling systems, the new BMW engine featured a recirculating wet sump oiling system with a drip feed to roller bearings; a design which BMW used until 1969. The R 32 also started the tradition of shaft drive, which was used on all BMW motorcycles until 1994.