BMW R100S

R100S

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Manufacturer	BMW Motorrad
Parent company	BMW
Production	1976–1980
Predecessor	BMW R90S
Engine	980 cc air-cooled two-cylinder boxer engine
Bore / stroke	94 mm × 70.6 mm (3.70 in × 2.78 in)
Compression ratio	9.5:1
Top speed	200 km/h (120 mph)
Power	65 hp (48 kW) @ 6,600 rpm (1976–1977) 70 hp (52 kW) @ 7,250 rpm (1978–1980)
Torque	75 N⋅m (55 lb⋅ft) @ 5,500 rpm (1976–1977) 77 N⋅m (57 lb⋅ft) @ 5,500 rpm (1978–1980)
Transmission	5-speed, dry single plate clutch
Suspension	Front: 200 mm (7.9 in) telescopic fork Rear: 125 mm (4.9 in) swingarm
Brakes	Front: Double 260 mm (10 in) disc brake Rear: drum brake (1976–1977) Rear: 260 mm (10 in) disc brake (1978–1980)
Tires	Front: 3.25 H 19 Rear: 4.00 H 18
Wheelbase	1,465 mm (57.7 in)
Dimensions	L: 2,130 mm (84 in) W: 746 mm (29.4 in) H: 1,210 mm (48 in)
Seat height	820 mm (32 in)
Weight	220 kg (490 lb) (wet)
Fuel capacity	24 L (5.3 imp gal; 6.3 US gal)

The R100S is a two-cylinder four-stroke air-cooled boxer engine motorcycle built by BMW Motorrad, from 1976 to 1980.

Engine

The engine is a 980 cc (60 cu in) two-cylinder four-stroke air-cooled boxer engine, with two pushrod operated overhead valves per cylinder, and is fueled by two constant depression carburators, built by Bing Carburetor.

The engine utilizes a wet sump lubrication system.

Transmission

The motorcycle features a dry single-plate clutch, and 5-speed gearbox, utilizing gear ratios of 4.4/2.86/2.07/1.67/1.50:1 and 3.38/2.43/1.93/1.67/1.50:1 for the optional sport version.

Chassis

The chassis consists of a double loop tubular frame, using a telescopic, 200 mm (7.9 in) travel hydraulically dampened fork for suspension of the front wheel, and a 125 mm (4.9 in) travel swingarm suspension of the rear wheel.

Brakes

The front wheel is braked by two 260 mm (10 in) disc brakes, using ATE single piston calipers. The rear wheel is braked by a 200 mm (7.9 in) drum brake, and by a single 260 mm (10 in) disc brake from 1978 and on.

Motorsport

The bike won the Castrol Six Hour race in 1977.

Color schemes

The R100S was produced in Motorsport White, Ocean Blue (Blue Motorsport), Dunkel Red, Classic Black, Hell Silver, Red Metallic, and Two Tone Red, with the addition of some custom and limited edition color schemes.