Information kindly supplied by P.Hawksley

www.bmbikes.co.uk


Start of Production

1978

Click to View Available Literature

End of Production

1984

Numbers Produced

18,015

Price

11,480 DM

Engine

 

Motor Type

Four-stroke two cylinder horizontally opposed "Boxer" engine, air cooled

Bore x Stroke

94 x 70.6 mm (3.70 x 2.78 in)

Displacement

980 cc

Max Power

70 hp (51 KW) at 7,250 rpm

Max Torque

77 Nm / 56 ft lb at 5,500 rpm

Compression Ratio

9.5 : 1

Valves Per Cylinder

2

Valve Control

OHV, using push rod and rocker arm

Carburation System

2 constant depression carburettors, Bing 94/40/105 - 94/40/106

Engine Lubricating System

Wet sump



Power Transmission

 

Clutch

Dry single plate, with diaphragm spring

Number of Gears

5

Gear Selection

Dog type gearbox (ratchet foot lever)

Gearbox Ratios

4.4 / 2.86 / 2.07 / 1.67 / 1.50 : 1 (Optional sport version: 3.38 / 2.43 / 1.93 / 1.67 / 1.50

Rear Wheel Ratio

1 : 3.0 or 1 : 2.91

Bevel/Crownwheel

11 / 33 teeth or 11 / 32 teeth



Electrical System

 

Ignition System

Battery ignition. From Sept 1980: contact free electronic ignition (Bosch)

Alternator

Bosch 12V/240 W

Starter

Bosch 0.7 Kw

Spark Plugs

Bosch W 225 T 30 / Beru 230/14/3 A / Champion N6Y






Chassis

 

Type of Frame

Double loop tubular frame with bolt on rear section

Front wheel suspension

Telescopic fork with hydraulic shock absorber

Rear wheel suspension

Long swinging arm with adjustable strut

Spring Travel Front/Rear

200 / 125 mm (7.87 x 4.92 in)

Wheel Rims, Front

1.85 B 19

Wheel Rims, Rear

2.75 C 18

Tyres, Front

3.25 H 19

Tyres, Rear

4.00 H 18

Brakes, Front

Dual disc brake 260 mm / 10.23 in diameter. ATE 1 piston caliper up to 1981. 1981 models Brembo 2 piston caliper

Brakes, Rear

Single disc brake 260 mm / 10.23 in diameter




Dimensions/Weights

 

Length x Width x Height

2210 x 746 x 1465 mm (87 x 29.37 x 57.67 in)

Wheel Base

1465 mm / 57.67 in

Fuel Tank Capacity

24 litres / 5.27 gal / 6.34 gal US

Unladen Weight with Full Tank

234 Kg / 515 lb to 1980. 1981 on 238 Kg / 525 lb

Max. Permissible Weight

398 Kg / 876 lb

Ground Clearance

165 mm / 6.49 in

Seat Height (Unladen)

820 mm (32.3 inches)

Fuel Consumption (at constant 90 Kph)

5.75 litres 100 Km / 49 mpg / 40 mpg US

Top Speed

190 Kph / 118 mph

Acceleration 0 - 100 Kph / 62 mph

5.0 seconds