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BMW R 39 (1925-1927) Specs, Performance & Photos

Segment: Clasic
Production years: 1925, 1926, 1927

BMW R 39 1925-1927
BMW R 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.

BMW R 39 1925-1927

BMW R 39 247

engine specs
Type:air-cooled, four-stroke, single vertical cylinder, OHV
Displacement:247 cm3
Bore X Stroke:2.67x2.67 in OR 68 mm
Compression Ratio:6:1
Horsepower:6/4000 KW(hp)/RPM
Torque:0/- lb-ft/RPM OR 0 Nm/RPM
Fuel System:1x20mm BMW Spezial
transmission specs
Gearbox:3 speed, manual
Clutch:dry, single plate
Primary Drive:-
Final Drive:shaft
chassis specs
Frame:steel
Front Suspension:plate spring, 4 laminae
Rear Suspension:hard-tail, sprung seat
Front Brake:150mm drum
Rear Brake:external shoe brake at the gearing (on cardan shaft)
dimension specs
Overall Length:80 in OR 2032 mm
Overall Width:31 in OR 787 mm
Seat Height:-
Wheelbase:-
Ground Clearance:-
Weight:242 lbs OR 110 kg
Fuel Capacity:2.64 gallons OR 10.0 L
tyres specs
Front:27 x 3.5
Rear:27 x 3.5
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