1981 BMW R65
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Engine |
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Motor Type |
Four-stroke two cylinder horizontally opposed "Boxer" engine, air cooled |
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Bore x Stroke |
82 x 61.5 mm (3.22 x 2.42 in) |
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Displacement |
649.6 cc |
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Max Power |
45 hp (33 Kw) at 7,250 rpm. From 1981 50 hp 37 Kw at 7,250 |
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Max Torque |
50 Nm / 36 ft lb at 5,500 rpm. From 1981 model: 52.3 Nm / 38 ft lb at 6500 rpm | |
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Compression Ratio |
9.2 : 1 |
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Valves Per Cylinder |
2 |
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Valve Control |
OHV, using push rod and rocker arm |
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Carburation System |
2 constant depression carburettors, Bing 64/32/2030 - 64/32/2040 or 64/32/307 - 64/32/308 |
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Engine Lubricating System |
Wet sump |
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Power Transmission |
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Clutch |
Dry single plate, with diaphragm spring |
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Number of Gears |
5 |
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Gear Selection |
Dog type gearbox (ratchet foot lever) |
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Gearbox Ratios |
4.4 / 2.86 / 2.07 / 1.67 / 1.50 : 1 |
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Rear Wheel Ratio |
1: 3.44 |
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Bevel/Crownwheel |
9 / 31 teeth |
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Electrical System |
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Ignition System |
Battery ignition. From 1981 model: Contact free electronic ignition |
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Alternator |
Bosch 280 W |
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Starter |
Bosch 0.7 hp |
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Spark Plugs |
Bosch W 5 D / Beru 14-5D / Champion N 6 Y |
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Chassis |
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Type of Frame |
Double loop tubular frame with bolt on rear section |
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Front wheel suspension |
Telescopic fork with hydraulic shock absorber |
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Rear wheel suspension |
Long swinging arm with adjustable strut |
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Spring Travel Front/Rear |
175 / 110 mm (6.88 / 4.33 in) |
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Wheel Rims, Front |
1.85 B 18 |
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Wheel Rims, Rear |
2.50 B 18 |
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Tyres, Front |
3.25 S 18 |
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Tyres, Rear |
4.00 S 18 |
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Brakes, Front |
Single disc brake 260 mm / 10.23 in diameter. Twin disc on later models. ATE 2 piston caliper to 1979. 1979 on models Brembo 2 piston caliper |
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Brakes, Rear |
Simplex drum brake 200 mm / 7.87 in diameter |
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Dimensions/Weights |
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Length x Width x Height |
2110 x 688 x 1090 mm (83.07 x 27.08 x 42.91 in) |
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Wheel Base |
1390 mm / 54.72 in to 1980. 1400 mm / 55.11 in |
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Fuel Tank Capacity |
22 litres / 4.83 gal / 5.81 gal US |
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Unladen Weight with Full Tank |
205 Kg / 451 lb |
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Max. Permissible Weight |
398 Kg / 876 lb |
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Ground Clearance |
130 mm / 5.11 in |
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Seat Height (Unladen) Up to 1980 |
770 mm (30.3 inches) |
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Seat Height (Unladen) 1981 On |
810 mm (31.9 inches) |
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Fuel Consumption |
4.6 litres 100 Km (at constant 90 Kph) / 61 mpg / 51 mpg US |
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Top Speed |
175 Kph / 108 mph |
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Acceleration 0 - 100 Kph / 62 mph |
5.9 seconds (1981 model on: 5.8 seconds) |
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