BMWR 39 1925 - 1927

　　In 1924 at the German Motor Show in Berlin, BMW presented the R39, its first single-cylinder model for the 250cc class, and released it to the general public in 1925.

　　The bike took its power from a 247cc four-stroke air-cooled engine that was able to pull out six hp at a peak of 4,000 rpm. The model had equipped a three-speed manual transmission and a dry, single-plate clutch.

　　The motorcycle presented the BMW design, which was common at the time, with a tubular steel frame and a drawn short swing fork for guiding the front wheel with leaf springs acting as suspension. On the rear, there was no suspension whatsoever except the spring mounted under the seat.

　　For the first time, the rear wheel brake was designed by BMW as a Cardan brake that acted on the outer ring of the Hardy disc.

　　The model featured as standard options wire-spoked wheels, whitewall tires, a rear luggage rack, a small headlight, a short exhaust, and tipped the scale at just 110 kg (242 lbs).

　　In the first year of production, the R39 was used to compete in the German DMV road championship in the 250cc class by Josef Stelzer, which won the event.

　　The design of the bike was not that different from the R37 model that was introduced at the same time and caused a cost problem. The production of the 1925 BMW R39 was stopped in 1927 and not pursued further.