1928 BMW R52



Start of Production

1928



End of Production

1929

Numbers Produced

4,377

Price

1,510 RM

Engine


Internal Designation

M 57

Motor Type

Four-stroke two cylinder flat twin

Bore x Stroke

63 x 78 mm (2.48 x 3.07 in)

Displacement

486 cc

Max Power

12 hp at 3,400 rpm

Compression Ratio

5.0 : 1

Valves

SV

Carburation System

1 carburettor, Type BMW Spezial 2 valve 22 mm

Engine Lubricating System

Forced feed lubrication

Oil Pump

Gear pump



Power Transmission


Clutch

Single plate, dry - two plates from engine No. 50761

Number of Gears

3

Shifting

Manual

Gearbox Ratios

2.83 / 1.55 / 1.08

Rear Wheel Ratio

1 : 4.38 or 1 : 4.75 (1 : 5.7 with sidecar)

Bevel/Crownwheel

13 / 57 teeth or12 / 57 (10 / 57 with sidecar)



Electrical System


Ignition System

Bosch high voltage magneto ignition

Generator

Bosch magneto generator on request

Spark Plugs

Bosch W 175



Chassis


Designation

F56

Frame

Twin loop steel tubular frame

Front wheel suspension

Plate spring, 6 laminae

Rear wheel suspension

Rigid

Wheel rims

Deep bed 19x 3

Tyres, Front

26 x 3.5 low pressure or 26 x 3.5 high pressure

Tyres, Rear

26 x 3.5 low pressure or 26 x 3.5 high pressure

Brakes, Front

Drum brake 200 mm / 7.87 in diameter

Brakes, Rear

External shoe brake at the gearing on Cardan shaft



Dimensions/Weights


Length x Width x Height

2100 x 800 x 950 mm (82.67 x 31.49 x 37.40 in)

Wheel Base

1400 mm / 55.11 in

Fuel Tank Capacity

12.5 litres / 2.74 gal / 3.30 gal US

Unladen Weight with Full Tank

152 Kg / 334 lb

Load Rating

210 Kg / 462 lb

Fuel Consumption

3.5 litres 100 Km approx / 80 mpg / 67 mpg US

Oil Consumption

1 - 2 litres per 1,000 Km approx.

Top Speed

100 Kph / 62 mph