R100 Diff and Driveshaft drawings.
R100RS '79 Tankcap ( photo and drawing)
R100RS '79 Fairing, disassembled
R100RS '79 Front wheel and calipers detail
Production
1976-1984
33,648 built
Engine
Type OHV four-stroke, horizontally-opposed "Boxer" twin, air-cooled
Bore x Stroke 94 x 70,6 mm
Cubic Capacity 980 ccm
Max Power 70 hp (51 KW) at 7250 rpm
Max Torque 76 Nm at 5500 rpm
Compression Ratio 9.5 : 1
Valves per Cylinder 2
Carburettors Bing 94/40/105-106
Engine Lubrication wet sump
Power Transmission
Clutch: dry single plate dry clutch
Gearbox: 5 speed
Gear Ratios: 4.4 / 2.86 / 2.07 / 1.67 / 1.50 :1 (optional sport version 3.38 / 2.43 / 1.93 / 1.67 / 1.50)
Bevel & Crownwheel: 11 / 33 teeth or 11 / 32 teeth
Electrics
Ignition battery ignition, from 1980: contact-free electronic ignition (Bosch)
Alternator Bosch 12 V/240 W
Starter Motor Bosch 0.6 hp (from 1978: 0.7 kW)
Spark Plugs Bosch W 225 T 30/Beru 230/14/3 A/Champion N 6 Y
Chassis
Frame Twin-loop tubular frame with bolt-on rear section
Front Suspension telescopic forks with hydraulic shock absorbers
Rear Suspension swinging arm
Spring Travel front/rear 200 / 125 mm
Rims: front 1.85 B 19 rear 2.50 B 18
Tyres: 3.25 H 19 front 4.00 H 18 rear
Brakes: Front dual discs 260 mm dia. Rear 1977: drum brake 200 mm dia. 1978: disc brake 260 mm.
Dimensions/Weights
Length x Width x Height 2210 x 746 x 1300 mm
Wheel Base 1465 mm
Tank Capacity 24 litres
Unladen Weight, full Tank 230 kg
Max permissible Weight 398 kg
Ground Clearance 165 mm
Fuel Consumption 5.75l per 100 km (at 90 kph)
Top Speed 200 kph
Acceleration 0-100 kph 4.6 sec
Editor's Note: Pics of my R100RS from the 80s. I think I had this one around 1981, probably just before the first K100RS. I rode it to Forbes and parked in the hangar while head honcho of GFA was lecturing. Long and interesting (to me) story.
The page was written for a major Sydney BMW dealer, along with a number of others. The owner had no understanding of the internet and totally misconstrued their purpose, and as a result the pages were removed. This page remained unfinished for several decades and was just recently rediscovered in the archives. Jan 2026.
