BMW R100RS 1977 Data:

Air-cooled flat-twin four-stroke. 94mm (3.7in) bore x 70.6mm (2.78in) stroke = 980cc (59.8cu in).
Maximum power (DIN) 70bhp at 7250rpm
maximum torque (DIN) 55.71b ft
Aluminium-alloy cylinder barrels and heads
Compression ratio 9.5: 1
2 valves per cylinder operated, via pushrods and rockers, by a single central camshaft
Two Bing constant-vacuum carburettors

Single-dry-plate clutch and five-speed gearbox with left-foot change
ratio: 1st 4.40, 2nd 2.86, 3rd 2.09. 4th 1.67, 5th 1.50:1
Shaft and hypoidbevel final drive to rear wheel ratio 3:1

Front-teleseopie fork with coil springs, hydraulic dampers and steering damper
Rear longitudinal rocker arm with progressive-action spring struts, three-position setting for rear springs

Front: Twin cross-drilled discs
Rear : drum

Spoked wheels standard (light-alloy optional)

227 Kg

Tank capacity:
24.15 Litres (5.25 gallons)

(c) W.P.Barendsen 1998