R47

1928 BMW R47 Technical Analysis & Specification Breakdown

At the heart of the 1928 BMW R47 allround motorcycle, BMW relies on a 494 cc (30.1 cu in) air-cooled two cylinder boxer, four-stroke powerplant. In factory specification, peak output is rated at 18 HP (13.1 kW) at 4,000 rpm, transferring power to the rear wheel through a 3-speed gearbox and shaft drive (cardan) final drive. With a specific output of 36.4 HP per liter, the engine character is prioritizing low-RPM tractability, mechanical longevity and relaxed throttle response over peak redline numbers.

On the scales, the R47 measures 126 kg (278 lbs) wet (curb), translating to a power-to-weight ratio of 0.14 HP/kg (7 kg per horsepower). Rider ergonomics and chassis geometry center around a 1,410 mm (55.5 in) wheelbase engineered for quick, flickable steering geometry. The 14-liter (3.7 US gal) fuel tank paired with a rated consumption of 3 L/100 km provides an estimated theoretical range of roughly 467 km (290 miles) between fill-ups, while factory top speed is listed at 110 km/h (68 mph).

Within MotoLibrary's BMW archive, this model family spans 2 indexed model years from 1927 to 1928, allowing buyers to track year-over-year changes in emissions tuning, weight and equipment.