In the late 1890s, German engineer Karl Benz designed a new type of four-stroke engine. It was a flat, horizontally opposed twin cylinder engine that involved two pistons reaching top dead centre and bottom dead centre at the same time, with the piston action likened to two boxing fighters trading blows, and the term ‘boxer’ engine was born. Early 1900s, BMW engineer Max Friz designed a small boxer engine which became extremely popular with early motorcycle manufacturers in Germany, because of how compact it was. Nicknamed the ‘Bayern-engine’, it was originally placed in motorcycles with the two cylinders running the length of the frame, but this caused the rear cylinder to overheat as it couldn’t benefit from passing air to cool it down.
Friz had the first BMW motorcycle on the drawing board by December 1922 with the flat-twin Boxer engine at the heart of the bike’s design. But to combat the rear cylinder cooling issue, Friz decided to simply turn the engine 90-degrees so that both cylinders stuck out the side of the frame to get sufficient airflow and cooling. Genius!
In 1923, Friz’s brainchild was released – the BMW R 32.  It was the first motorcycle that BMW had built and it paved the way for all boxer-powered BMW motorcycles of the future. The 8bhp engine was fitted with a three-speed transmission and instead of using a chain to drive the power from the engine to the rear wheel, it was shaft driven for extra reliability. Following the R 32’s undeniable success, building and selling thousands of bikes between 1923-1926, BMW wanted more.