The R32 also had a flat-twin two-cylinder side-valve 'boxer' engine design. The 494cc R32 had an exposed 'cardan' driveshaft final drive, and a three-speed transmission. The chassis had a rigid tubular-frame with sprung seat, and twin-cantilever front suspension.
1923 BMW R32 494 cc Horizontally-Opposed Twin
The flat-twin engine's longitudinal crankshaft enabled the final drive-shaft to be driven directly from the gearbox. There was no front brake on the original R32, and the rear brake was a large friction-type ring mounted to the rear wheel, that was slowed by wooden blocks.
The R32's two-cylinder four-stroke 'boxer' engine produced 8.5 hp at 3,200 rpm, generating a top speed of 60 mph (96 km/h). A total of 3,090 units were produced in the R32's 3 year production cycle.
In 1925, BMW introduced the 250cc R39, using its first proprietary single-cylinder engine. All BMW motorcycles were manufactured at the BMW Motorradwerke's factory in München (Munich), where over 440,000 motorcycles were built between 1922 and 1969, when the motorcycle factory was moved to Berlin.