| MODEL | BMW R 100S 1979 - 1980 |
| Year | 1979 - 1980 |
| Engine Type | Four stroke, two cylinder horizontally opposed Boxer, 2 valves per cylinder |
| Displacement / Capacity | 980 cc / 59.8 cu in |
| Bore X Stroke | 94 x 70.6 mm |
| Compression Ratio | 9.5:1 |
| Cooling System | Air cooled |
| Max Power | 51 kW / 70 hp @ 7250 rpm |
| Max Torque | 76 Nm / 7.7 kgf-m / 56 lb-ft @ 6000 rpm |
| Ignition | Battery ignition |
| Induction | 2 x Bing 94/40/105 - 94/40/106 constant depression carburettors |
| Start System | Electric |
| TRANSMISSION SPECS | |
| Lubrication | Wet sump |
| Gear Box | 5 Speed |
| Clutch | Dry single plate, with diaphragm spring |
| Final Drive | Shaft |
| CHASSIS SPECS | |
| Frame | Double down tubes, dual cradle |
| Front Suspension | Telescopic fork with hydraulic shock absorber, 200 mm / 7.8 in travel |
| Rear Suspension | Long swinging arm with adjustable struts, 125 mm / 4.9 in travel |
| Front Brakes | 2 x 260 mm discs, 2 piston calipers |
| Rear Brakes | Drum |
| DIMENSION SPECS | |
| Overall Length | 2130 mm / 83.8 in |
| Overall Width | 746 mm / 29.37 in |
| Overall Height | 1210 mm / 47.6 in |
| Seat Height | 820 mm / 32.3 in |
| Wheelbase | 1465 mm / 57.67 in |
| Ground Clearance | 165 mm / 6.49 in |
| Dry Weight | — |
| Wet Weight | 220 kg / 484 lbs |
| WHEEL SPECS | |
| Front Tyre | 3.25-19 |
| Rear Tyre | 4.00-18 |
| FUEL SYSTEM | |
| Fuel Capacity | 24 Litres / 6.3 US gal |
| Fuel Consumption | 5.2 L/100 km / 19.1 km/l / 45 US mpg |
| Top Speed | 200 km/h / 124 mph |
Photo: K1200RSRIDER, CC BY-SA 4.0, via Wikimedia Commons
Photo: photobeppus, CC BY-SA 2.0, via Wikimedia Commons
The final run of the R 100 S kept the 70 hp, 980 cc boxer and the small cockpit fairing. For 1980 BMW fitted Brembo front calipers with a handlebar-mounted master cylinder in place of the earlier ATE system. The S was dropped after 1980, and its sporting role passed to the R 100 CS.
