Information kindly supplied by P.Hawksley

www.bmbikes.co.uk

Start of Production

1941

Click to View Available Literature

End of Production

1944

Numbers Produced

18,000 approx.

Price

2,630 RM

Engine

 

Internal Designation

275/2

Motor Type

Four-stroke two cylinder flat twin

Bore x Stroke

78 x 78 mm (3.07 x 3.07 in)

Displacement

745 cc

Max Power

26 hp at 4,000 rpm

Compression Ratio

5.8 : 1

Valves

OHV

Carburation System

2 x carburettor type Graetzin Sa 24/1 and Sa 24/2

Engine Lubricating System

Forced feed lubrication

Oil Pump

Gear pump



Power Transmission

 

Clutch

Single plate, dry

Number of Gears

"Road": 4 + 1 reverse gear, "off-road": 3 + 1 reverse gear

Shifting

Foot and manual shifting with selector lever "off-road" + "road"

Gearbox Ratios

"Road": 3.22 / 1.83 / 1.21 / 0.90, reverse gear 2.41, "off-road": 4.46 / 2.54 /1.67, reverse gear 3.3

Rear Wheel Ratio

1 : 6.05 (from production No. 754056 1 : 5.69)



Electrical System

 

Ignition System

Magneto ignition

Generator

Noris DS 6/50

Spark Plugs

Bosch W 175 T1






Chassis

 

Designation

275/1

Frame

Multi part, bolted steel tubular frame

Front wheel suspension

Telescopic fork

Rear wheel suspension

Rigid, plate springs on the boat, tube springs on sidecar wheel

Wheel rims

3D x 16

Tyres, Front

4.5 x 16 (off road block profile)

Tyres, Rear

4.5 x 16 (off road block profile)

Brakes, Front

Drum brake 250 mm / 9.84 in diameter, mech.

Brakes, Rear

Drum brake 250 mm / 9.84 in diameter, mech; sidecar drum brakes 250 mm / 9.84 in diameter, hydraulic




Dimensions/Weights

 

Length x Width x Height

2400 x 1730 x 1000 mm (94.48 x 68.11 x 39.37 in) (with sidecar)

Wheel Base

1444 mm / 56.85 in

Fuel Tank Capacity

24 litres / 5.27 gal / 6.34 gal US

Unladen Weight with Full Tank

400 Kg / 881 lb with original sidecar

Load Rating

270 Kg / 594 lb

Fuel Consumption

Approx. 6.3 litres per 100 Km / 44 mpg / 37 mpg US (road), 8.5 litres per 100 Kph / 33 mpg / 27 mpg US (off-road)

Oil Consumption

Approx. 0.5 - 1 litre per 1,000 Km

Top Speed

95 Kph / 59 mph