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Motorworld’s newspaper №46

The company BMW initially relied on the mass production, and of course, the mass motorcycle should be fast.
The first step to the ideal was the model R37 – a powerful bike, but too expensive for the average buyer. German engineers found a way out – reducing production costs by simplifying the design.

BMW R47 в полной комплектации

Letter from BMW confirming the production date of the motorcycle (March 03, 1928) and the date when it was shipped to a dealer in Danzig (April 25, 1928).

BMW engineers had taken 500 cc OHV engine from R37 as a base, added simplified frame and suspension, and got rid of all electricals that were not a must. AAs a result, they were able to lower the motorcycle cost by 36% while keeping all of the bike’s racing ambitions thanks to the engine.

R47 flat-twin OHV engine was the same as the one used on the touring model R42, except its rating increased to 18 h.p. and the maximum speed increased to 110 km/h. BMW sold 1720 R47 motorcycles – ten times more than R37! Most of the R47 motorcycles were sold to German racing clubs.

The main reason for the R47 success was that BMW did not present the new model as a racing-only motorcycle. The model had been offering in a “bare” version, but the client could choose from many options, e.g. generator, horn, and headlight. A fuel tank of larger capacity was also offered as an option. With a larger tank, R47 might be a part of the «Gran Turismo» class.

Model R47 occupies a place of honor among BMW motorcycles because it was truly advanced for its time. For example, roller bearers were used for the first time (in the design of the valve rocket arm), replaceable bushings, and an innovative control system (except for manual shifting).

Manufacturer Bayerische Motoren Werke, AG (Germany)
Years of manufacture 1927-1928
Quantity produced, units 1 720
Price 1 850 RM
Today’s value 5373,81 $
ENGINE AND TRANSMISSION
Type Twin-cylinder, horizontally-opposed
Engine capacity, cc 494
Bore and stroke, mm 68 х 68
Engine rating 18 h.p. at 4000 rpm.
Sparking Bosch magneto
Carburetor BMW Spezial 22 mm
Battery 6 V
Clutch Single-plate, dry
Transmission 3-speed
FRAME AND WHEELBASE
Frame type Duplex tubular
Front suspession Leaf spring, 5 plates
Rear suspension Rigid
Brakes Front – drum-type, rear– foot brakes (on cardan shaft)
Wheel size 3.00х26 when using high-pressure tyres, 3.50х27 when using low-pressure tyres
Dimensions
Length, mm
2 100
Width, mm
   800
Height, mm
   950
Wheelbase, mm
1 410
Ground clearance, mm
   110*
Seat height
   760*
Mass, kg
   130
Gas tank size, l
     14
Maximum speed, km/h
   110
Range, km

* – Data on the results of metering at the exhibit “Motorworld by V.Sheyanov”.


Books:

PDF

Exploitation guide BMW R47 (ger.)