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Engine R 80 G/S
Type Air-cooled flat twin, transversely mounted, with overhead valves in hemispherical combustion chambers
Max. power output (kW) 37
- at engine speed (min-1) 6590
Max. torque (Nm) 56.7
- at engine speed (min-1) 5000
Max. permissible engine speed (min-1) 7400
Max. continuous engine speed (min-1) 7290
Bore/stroke (mm) 84.8 / 79.6
Displacement, effective (cm3) 797.5
- for taxation purposes (cm3) 785
Compression ratio 8.2 to 1
Direction of rotation Clockwise, looking at alternator
Fuel consumption by DIN standard test method (liters/100 km) 5.0
(lmp. US mile/gal) 56.5/47.0
Carburetors R80 G/S
Type Two inclined Bing constant-depression carburetors with needle jet, vacuum slide throttle butterfly and central lever float.
Ref. No., left V 64/32/305
Right V 64/32/306
Throat diameter (mm) 32
Main jet 145
Needle jet 2.64
Jet needle No. 46-241
Needle position 4
Idle jet 45
Idle air jet diameter 1
Transmission R 80 G/S
Clutch Single dry plate with increased leverage diaphragm spring
Gearbox 5-speed, with dog-clutch engagement, forming a single unit with the engine block; drive torque damping in all gears, hook-action gear selection
Gear ratios 1st 4.4 to 1
  2nd 2.86 to 1
  3rd 2.07 to 1
  4th 1.67 to1
  5th 1.50 to 1
Rear wheel drive Enclosed universal-joint shaft in swinging arm tube, with universal joint at gearbox end and curved-spline coupling at final drive end; with torsional vibration damper
Final drive Crownwheel and spiral bevel pinion, Palloid tooth pattern
Final drive ratio 3.36 to 1
Number of teeth 11/37
Speedometer drive ratio (km) 0.773
(miles) 1.244
Frame R80 G/S
Frame pattern Twin loop steel-tube frame with bolted-on rear subframe; sidecar attachment not permitted
Location of manufacturer's plate and frame number On right gusset plate between steering head and frame
Front suspension Telescopic forks with large volume double-acting hydraulic dampers; travel 290 mm (7.9 in)
Rear suspension Lightweight swinging arm with three position spring strut ('Monoshock') with double acting hydraulic damper; travel 179 mm (6.7 in)
Max steering lock at forks 47o
Front wheel castor 114mm (4.49in)
Front brake Hydraulic single disc with fixed caliper
Disc diameter (mm) 260 (10.2 in.)
Effective lining area (cm2) 37 (5.74 in.2)
Rear brake Light alloy drum in full-width hub; leading and trailing shoes
Drum diameter (mm) 200 (7.9 in.)
Effective lining area (cm2) 89 (13.8 in2 )
Frame R80 G/S
Wheels Spoked, with hardened aluminum rims of WM profile
Rim sizes - front 1.85 B x 21
-rear 2.15 B x 18
Tires Special pattern, with inner tube (see also page 33, 'Important note')
Sizes - front 3.00 - 21 48 R
-rear 4.00 - 18 64 R
Tire pressures in bar (Ib/in2) with tires cold  
Front Rear
1.9(27) 1.8(26)
Two up  
Front Rear
2.1(30) 2.2(31)
Note: comply with minimum legal tread depth requirements,  
BMW minimum tread depth recommendations:  
up to 130km/h (81 mile/h) 2 mm (0.08 in)
above 130km/h (81 mile/h) 3 mm (0.12 in)
Fuels and lubricants R 80 G/S
Fuel Regular grade petrol (gasoline) to German Industrial Standard DIN 51609 or equivalent, minimum octane number 91 (RM) or 82 (MM)
Tank capacity 19,5 liters (4.3 lmp./5.2 US gal)
including reserve of app. 2 liters (0.44 lmp./0.53 US gal)
Engine oil Brand-name HD oil for spark-ignition engines, API Class SE
Viscosity/outside temperatures  
Fuel and lubricants R 80 G/S
Engine oil content if filter element is not changed 2 liters (3.5 Imp. Pints, 2.1 US quarts)
if filter element is changed 2.25 liters (4.0 Imp. Pints, 2.4 US quarts)
Gearbox oil content 0.8 liter (1.4 Imp. Pints, 0.85 US quart)
Rear swinging arm oil content 0.15 liter (0.26 Imp. Pint, 0,16 US quart)
Final drive oil content 0.35 liter (0.62 Imp. Pint, 0.37 US quart)
Brand-name hypoid gear oil  
above 50C (410F) SAE 90
below 50C (410F) SAE 80
Telescopic forks - oil grades Shell 4001, Shell Aero Fluid 4, Castro DB Hydraulic Fluid, Castrol 1-318 Shock Absorber Oil, Aral P3441 Shock Absorber Oil, Mobil Aero HFA, Mobil DTE 1, Esso Universal J13
Content per fork leg 0.22+0.01 liter (0.39 +0.02 Imp. pint, 0.23 + 0.01 US quart)
Wheel bearings and all other greasing points Brand-name multipurpose grease, drip point 1800C (3500F)
Battery terminals Acid-free grease, 'Vaseline'
Brake fluid  
Grade DOT 4; ATE 'SL' brake fluid
Quantity required to fill and bleed empty system app 0 3 liter (106 fl. oz)
Electrical system  
Battery Varta 12 V, 9 Amp/h (optional extra 12 V, 16 Amp/h battery in conjunction with electric starter)
Starter (optional extra) Bosch 0.7 kW
Alternator Bosch 280 W
Voltage regulator Wehrle E 1051 B/14 V
Coil Bosch 12 V twin-spark
Ignition trigger Contactless ignition pulse generator (Hall effect) with integral centrifugal advance4 Mfr Bosch
  Advance movement begins at 1500 rnin-1
Advance movement ends at 3500 rnin-1
Ignition timing 6o before TDC at 800 - 1100 rnin-1
Maximum advance 32 o before TDC at min. 3000 rnin-1
Spark plugs Bosch W7D
Beru 14-70
Champion N 10 Y
Electrode gap 0.6 + 0.1 mm (0.024 + 0.004 in)
Flasher unit Bosch 0 335 200 043
High and low (dipped) headlight beams H 4 halogen bulb, 60/55 Watt dual filament
Parking light 12 V, 4 Watt
Telltale and warning lamps:  
High beam (blue) 12V, 3Watt
Neutral (green) 12V, 3Watt
Turn indicator (green) 12V, 3Watt
Charge(red) 12V, 3Watt
Oil pressure(red) 12V, 3Watt
Speedometer Lighting 12V, 3Watt
Fuses (2) 8 Arnp
Flashing turn indicators, (2 front, 2 rear) 12V, 21 Watt
Rear/brake light 12V, 21/5 Watt
Dimensions R80 G/S
Overall width (engine) (mm) 746 (29.4 in.)
Overall width (handlebars, excl. mirrors) (mm) 820 (32.3 in.)
Overall height excl. mirrors (unladen) (mm) 1150 (45.3 in.)
Dualseat height (unladen) (mm) 860 (33.9 in.)
Overall length (mm) 2230 (87.8 in.)
Wheelbase (mm) 1465 (57.7 in.)
Ground clearance (with rider weighing 75kg ,165 lb.)) (mm) 175 (6.9 in.)
Ground clearance at unladen weight (mm) 218 (8.6 in.)
Dry weight (DIN standard unladen weight) (kg) 167 (368 lb.)
Weight with tank full, ready for road, incl. Tools (kg) 186 (410 lb.)
Gross weight limit unladen weight + rider and pillion and/or luggage (kg) 398 (877 lb.)
Power/weight ratio, ready for road, incl. rider (75 kg (165 lb.) (kg/bhp) 7.05(15.5 lb/bhp)
Permissible wheel loads  
- front, tire pressure 2.1 bars (30 lb/in2) (kg) 178 (392 lb.)
- rear tire pressure 2.2 bars (31 lb/in2 ) (kg) 270 (595 lb.)
Max number of persons to be carried 2 (1 rider, 1 pillion passenger)
Performance R80G/S
Acceleration from 0 to 100km/h (0 - 62 mile/h) 5.6 s
- from 0-140km/h (0 - 87 mile/h) 10.6 s
-from 0 to 400m(1312ft) 13.8 s
- from 0 to 1000m (3251 ft) 26.5 s
Speeds in gears, with upward shifts at 7000 /min  
1st (km/h) 57(35 mile/h)
2nd (km/h) 88 (55 mile/h)
3rd (km/h) 122 (76 mile/h)
4th (km/h) 152 (94 mile/h)
Top speed, rider seated (km/h) app. 165 (103 mile/h)
rider crouched (km/h) app. 168 (104 mile/h)
The maximum speed the motorcycle can actually achieve depends to a great extent on aerodynamic drag caused by the size of the rider, his position and his clothing, the road surface and weather conditions