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1984 BMW R 100RS Overview
The 1984 BMW R 100RS is a classic motorcycle built around 980 cc of displacement. Under the tank sits an Air-Cooled Boxer Twin engine running OHV Pushrod 2-Valve valve actuation, a compression ratio of 9.5:1. 1984 BMW R 100RS delivers 51 kW @ 7000 rpm of peak power and 76 Nm @ 6000 rpm of torque. The factory-quoted top speed stands at 196 km/h, making it a capable performer in its class. From a practical standpoint, the 1984 R 100RS tips the scales at 230 kg, carries a 24-litre fuel tank, offers a seat height of 820 mm and spans a 1465 mm wheelbase. That's roughly 34 kg heavier than the average classic motorcycle in our database. Scroll down for the complete 1984 BMW R 100RS spec sheet covering every technical detail from suspension travel to tyre sizes.
1984 BMW R 100RS compared with other bikes in the Classic category
Here is how the 1984 BMW R 100RS stacks up against other bikes in the Classic category in our database. Each model counts once, using the model year closest to this one, and the comparison covers up to 909 models.
- Power output of 51 kW is higher than that of 520 of the other 591 bikes in the Classic category.
- Only 107 of the other 908 bikes in the Classic category have a larger engine displacement than the 980 cc of the R 100RS.
- With 196 km/h, the R 100RS has the joint 62nd highest top speed of 438 bikes in the Classic category, 31% above the category average of 149 km/h.
- Narrowing the field to the 76 models within five model years of it, the power output of 51 kW is higher than that of 64 of the other 75.
Versus the 1983 model
Compared with the 1983 model, wet weight dropped from 247 kg to 230 kg (-17 kg), displacement increased from 979 cc to 980 cc (+1 cc) and top speed climbed from 193 km/h to 196 km/h (+3 km/h).
1984 R 100RS - Pros & Cons
Strengths
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Strong power output: 1984 BMW R 100RS makes 51 kW @ 7000 rpm with 76 Nm @ 6000 rpm of torque - competitive figures for its class.
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Strong front braking: The disc front brake gives excellent stopping power and responds well to aftermarket braided lines.
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Large fuel range: The 24-litre tank is generously sized, translating to extended range between stops - ideal for touring or longer commutes.
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Low-maintenance final drive: Shaft final drive means no chain to clean, lube or adjust - meaningfully less routine maintenance than a chain-driven equivalent.
Considerations
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Carburetor fuelling: Carbureted engines need occasional jetting attention and can be reluctant in cold weather or at altitude compared to modern fuel-injected alternatives.
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Drum rear brake: The drum rear brake is adequate but lacks the modulation and fade resistance of a disc setup found on more modern equivalents.
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Tall seat height: The 820 mm seat height will challenge shorter riders - tiptoeing at low speeds is something to factor into your decision.
Wear Points & Servicing Notes
Heat management in traffic
R 100RS's air-cooled design means engine-bay temperatures build up more in stop-start traffic than on a liquid-cooled equivalent - a function of the cooling method itself, not a defect. Mesh riding gear and avoiding prolonged idling help in hot climates.
Carburetor maintenance
The R 100RS uses carburetion rather than fuel injection, which means jetting is altitude- and temperature-sensitive and benefits from a clean-and-rejet after extended storage or an exhaust change.
Brake disc and pad wear
The disc front brake gives strong, progressive stopping power. Disc thickness and pad depth are worth checking at every tyre change, since worn pads can score the disc surface.
Suspension condition on used examples
Up front, the R 100RS runs Telescopic fork with hydraulic shock absorber and Long swinging arm with adjustable strut at the rear. On a used example, check fork seals for weeping oil and test the rear linkage for play - seals are a relatively cheap fix but useful when negotiating price.
Final drive maintenance
Final drive is by shaft - no chain or belt maintenance at all, though the drive-shaft oil should be changed on the manufacturer's interval.
Frame & chassis check
The frame is Double sown tubs, dual cradle - worth a visual check for corrosion or impact damage around the head-stock and swingarm pivot on any used example, since frame damage is far costlier to fix than any service item.
Handling the weight at a standstill
At 230 kg, the R 100RS is a substantial machine - low-speed manoeuvring in car parks takes more physical effort than on a lighter bike, though the weight disappears once rolling.
R 100RS - Buying & Maintenance Guide
What to check before buying
When inspecting a used 1984 BMW R 100RS with its 980 cc classic, start with the basics: check the service book for oil change frequency, inspect the drivetrain for wear, and look for oil seepage around the engine casings and rocker covers. This model runs shaft final drive, so ask for proof the shaft-drive gear oil has been changed on schedule - it's easy to overlook since there's no chain to draw attention to it. Now 42 years old, this classic is as likely to show age-related wear (perished rubber, seized fasteners, degraded seals) as mileage-related wear. A cold start test is invaluable - a well-maintained R 100RS should fire up cleanly and settle to a smooth idle within a few seconds.
Oil and filter changes
Regular oil changes are the single most important maintenance task for the R 100RS's 980 cc air-cooled boxer twin. Stick to the manufacturer's interval - typically every 6,000 km or once a year, whichever comes first. With a 9.5:1 compression ratio, running the octane grade specified in the manual matters more than on a lower-compression engine. Always use the correct viscosity grade as specified in the owner's manual.
Carburetor upkeep
Keep the carburetors clean and free of deposits. If the R 100RS has been stored, strip and clean the carb float bowls before attempting to start it. Pilot jets are the first to block and the last to be checked - always include them in any carb rebuild.
1984 BMW R 100RS - Frequently Asked Questions
What engine does the 1984 BMW R 100RS have?
The 1984 BMW R 100RS uses an Air-Cooled Boxer Twin engine with 980 cc of displacement. It is air cooled.
What is the top speed of the 1984 BMW R 100RS?
The 1984 BMW R 100RS has a factory-quoted top speed of 196 km/h. Real-world speeds vary depending on rider weight, conditions and state of tune.
How much does the 1984 BMW R 100RS weigh?
The 1984 BMW R 100RS weighs 230 kg. This is the manufacturer's wet figure.
How much power does the 1984 BMW R 100RS make?
The 1984 BMW R 100RS produces 51 kW @ 7000 rpm of power and 76 Nm @ 6000 rpm of torque. These are peak figures.
What is the fuel tank capacity of the 1984 BMW R 100RS?
The 1984 BMW R 100RS has a 24-litre fuel tank. At around 5-6 litres per 100 km, that is roughly 400-480 km between stops.
Is the 1984 BMW R 100RS suitable for shorter riders?
The 1984 BMW R 100RS has a seat height of 820 mm. This is towards the tall end of the spectrum and will require most riders under 175 cm to tiptoe at stops.
What brakes does the 1984 BMW R 100RS have?
The 1984 BMW R 100RS uses 2 x Ø260mm discs, 2 piston calipers at the front and Simplex ∅200 mm drum at the rear.
What tyre sizes does the 1984 BMW R 100RS use?
The 1984 BMW R 100RS runs 3.25 - H19 front and 4 - H18 rear tyres. A good selection of sport, touring and all-weather rubber is available in these sizes.
What gearbox does the 1984 BMW R 100RS have?
The 1984 BMW R 100RS is fitted with a 5 Speed transmission.
BMW R 100RS Spec Evolution
The BMW R 100RS was produced across 9 model years (1976-1989). The table below highlights the key specifications that changed across the production run - useful whether you are comparing years or tracking down a specific variant.
| Specification |
1976 |
1977 |
1979 |
1981 |
1983 |
1985 |
1987 |
1988 |
1989 |
| Max Power |
51 kW / 70 hp / @ 7000 rpm |
51 kW / 70 hp / @ 7000 rpm |
51 kW / 70 hp / @ 7000 rpm |
51 kW / 70 hp / @ 7000 rpm |
51 kW / 70 hp / @ 7000 rpm |
51 kW / 70 hp / @ 7000 rpm |
- |
- |
43.8 kW / 59.5 hp @ 6500 rpm |
| Wet Weight |
230 kg / 506 lbs |
230 kg / 506 lbs |
230 kg / 506 lbs |
247.0 kg / 544.5 lbs |
230 kg / 506 lbs |
230 kg / 506 lbs |
243.0 kg / 535.7 lbs |
243.0 kg / 535.7 lbs |
243.0 kg / 535.7 lbs |
| Engine Type |
- |
- |
- |
Air-Cooled Boxer Twin |
Two cylinder boxer |
Air-Cooled Boxer Twin |
Two cylinder boxer |
Two cylinder boxer |
Two cylinder boxer |
| Top Speed |
196 km/h / 121.5 mph |
196 km/h / 121.5 mph |
196 km/h / 121.5 mph |
196 km/h / 121.5 mph |
196 km/h / 121.5 mph |
196 km/h / 121.5 mph |
186.0 km/h / 115.6 mph |
186.0 km/h / 115.6 mph |
186.0 km/h / 115.6 mph |
| Fuel Capacity |
24 Litres / 6.3 US gal |
24 Litres / 6.3 US gal |
24 Litres / 6.3 US gal |
24 Litres / 6.3 US gal |
24.00 litres / 6.34 gallons |
24 Litres / 6.3 US gal |
22.00 litres / 5.81 gallons |
22.00 litres / 5.81 gallons |
22 Litres / 5.8 gal |
| Displacement (cc) |
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- |
- |
980 cc |
979.00 cc |
980 cc |
979.00 cc |
979.00 cc |
979.00 cc |
| Displacement (ci) |
- |
- |
- |
59.8 cu-in |
59.74 cubic inches |
59.8 cu-in |
59.74 cubic inches |
59.74 cubic inches |
59.74 cubic inches |
| Fuel Control |
- |
- |
- |
OHV Pushrod 2-Valve |
OHV |
OHV Pushrod 2-Valve |
OHV |
OHV |
OHV |
Key Specifications
Engine
Air-Cooled Boxer Twin
Power
51 kW / 70 hp / @ 7000 rpm
Torque
76 Nm / 7.75 kgf-m / 56 ft-lb @ 6000 rpm
Top Speed
196 km/h / 121.5 mph
Fuel Capacity
24 Litres / 6.3 US gal
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Full 1984 BMW R 100RS Specifications
Year
1984 - 85
Make
BMW
Model
R 100RS
Make Model
BMW R 100RS
Seat Height
820 mm / 32.3 in
Wheelbase
1465 mm / 57.67 in
Ground Clearance
165 mm / 6.49 in
Height
1300 mm / 51.8 in
Length
2130 mm / 83.8 in
Width
746 mm / 29.37 in
Dry Weight (lbs.)
210 kg / 463 lbs
Fuel Capacity
24 Litres / 6.3 US gal
Wet Weight
230 kg / 506 lbs
Stroke
70.6 mm
Displacement (cc)
980 cc
Displacement (ci)
59.8 cu-in
Engine Type
Air-Cooled Boxer Twin
Fuel Control
OHV Pushrod 2-Valve
Displacement
980 cc / 59.8 cub in.
Engine Detail
Four stroke, two cylinder horizontally opposed Boxer, 2 valves per cylinder
Bore x Stroke
94 x 70.6 mm
Compression Ratio
9.5:1
Cooling System
Air cooled
Fuel Consumption
4.8 L/100 km / 20.8 km/l / 49 US mpg
Fuel Induction
2 x Constant depression carburettors, Bing 94/40/105 - 94/40/106
Ignition
Battery ignition
Lubrication
Wet sump
Starter
Electric
Clutch
Dry single plate, with diaphragm spring
Final Drive
Shaft
Final Drive Gear Ratio (Bevel/Crown Teeth)
11/32 teeth or 10/32 teeth
Gear Ratios
1st 3.38 / 2nd 2.43 / 3rd 1.93 / 4th 1.67 / 5th 1.50
Transmission / Drive
5 Speed
Frame Type
Double sown tubs, dual cradle
Suspension - Front
Telescopic fork with hydraulic shock absorber.
Suspension - Rear
Long swinging arm with adjustable strut.
Wheel Travel - Front
200 mm / 7.8 in
Wheel Travel - Rear
125 mm / 4.9 in
Alternator
Bosch 12V/240 W
Brakes - Front Diameter (mm)
260 mm
Brakes - Front Diameter (in.)
10.2 in
Brakes - Rear Diameter (mm)
200 mm
Brakes - Rear Diameter (in.)
7.9 in
Brakes - Front
2 x Ø260mm discs, 2 piston calipers
Brakes - Rear
Simplex ∅200 mm drum
Tyres - Front
3.25 - H19
Tyres - Rear
4.00 - H18
Wheel Ratio - Rear
1:2.91 or 1:3.00
Wheels - Front
2.15 - B19
Wheels - Rear
2.50 - B18
Specifications are compiled from manufacturer documentation and cross-referenced
technical sources, and corrected on an ongoing basis.
Spot an error? Let us know.
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