BMW R57 Compressor
Ten years after the collapse of its aero engine business at the close of WW1, BMW released the R57, based and developed from the very first BMW-badged motorcycle, the R32, which famously featured a 493cc twin-cylinder, sidevalve engine with horizontally opposed cylinders. This "flat twin" layout would forever be associated with the marque, and can be seen within the design of the R57. Production of the model lasted only three years, making this 1928 R57 one of the rarest, and most sought-after BMWs of the period.