YEAR 1923

   Because the earlier BMW motorcycles had suspension problems they were not able to sell much. So they start to develop the R32 motorcycle, which was the first BMW bike sold at an amount worth to mention (3100 bikes until 1926). The BMW R32 motorcycle causes a strong impression at its world première at the Berlin Automobile Show in 1923. With the R32, BMW succeeds in moving into vehicle construction even before the development of automobiles. This is the moment when the history of the BMW boxer engine begins and will continue until the present day. The top speed of this 2-cylinder 494cc motorcycle was around 59 mph (95 km/h).

                                                                        BMW R32 - 1923-1926 

     The R32 became the foundation for all future boxer powered BMW motorcycles. BMW oriented the boxer engine with the cylinder heads sticking out on each side for superior cooling. Other motorcycle manufacturers aligned the cylinders with the frame as V-twins, one cylinder facing toward the front wheel and the other, troubled by receiving hot air from the front cylinder, toward the rear wheel.

BMW - R32 Specifications 


Year:                 1923 - 1926
Number sold:   3,090
Price:                DM 2,200.
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Engine:

Internal designation        M 2 B 33

Type                              four-stroke two-cylinder flat twin (boxer)

Bore/stroke                   68 x 68 mm

Cubic capacity              494 cm3 / 30 in.3

Maximum power           8.5 HP at 3,200 RPMs

Compression ratio         5.0 : 1

Valves per cylinder         2 SV

Carburetion system        1 carburettor Type BMW Spezial 22mm

Engine lubrication            forced-feed lubrication

Oil pump                        gear pump
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Power transmission:

Clutch                         single discs, dry

Number of gears         3

Shifting                        manual

Gear ratios                 2.27 / 1.50 / 1.08

Rear wheel ratio        4.41 : 1 (with sidecar 5.36 : 1)

Bevel/crown wheel    17 / 75 teeth (with sidecar 14 / 75)
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Electrical system:

Generator               magneto generator (on request)

Ignition                   Bosch magneto ignition

Spark plugs            Bosch W 145
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Suspension:

Designation                R 32

Type of frame            twin-loop, tubular

Front suspension       twin cantilever spring

Rear suspension        rigid (none)

Wheel rims                26 x 2.5

Tires front                 26 x 3

Tires rear                  26 x 3

Brakes front             drum brake Ø 150 mm (1924 and on)

Brakes rear              block brake
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Dimensions and weights:

Length x width x height            82.7 x 31.5 x 37.4 inches (2100 x 800 x 950 mm)

Wheel base                              54.3 inches (1380 mm) with sidecar 1415 mm

Tank capacity                            3.7 gals. (14 liters)

Unloaded weight, full tank         269 lbs. / 122 kg

Permitted loading                      not available

Fuel consumption                      78 MPG (± 3 liters / 100 km)

Oil consumption                        ± 6.2 quarts / 1000 miles (± 2.5 liters / 1000 km)

Top speed                                 ± 60 MPH (± 96 km/h)
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