1981 BMW R 65 Specifications

Name: 1981 BMW R 65
Brand: BMW

Classic • Specs last verified 13 July 2026

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1981 BMW R 65 Overview

BMW R 65 is a classic motorcycle, displacing 649 cc. Power comes from a Two cylinder boxer engine running OHV valve actuation, a compression ratio of 9.2:1. Bore and stroke come in at 82 x 61.5 mm. On the performance side, it delivers. Top speed is factory-quoted at 175 km/h. On the road, the 1981 R 65 tips the scales at 204 kg and carries a 22-litre fuel tank. That's roughly 9.9 kg heavier than the average classic motorcycle in our database. The full 1981 BMW R 65 spec sheet below covers every technical detail, from suspension travel to tyre sizes.

1981 R 65 - Pros & Cons

Strengths

Large fuel range: A 22-litre tank means fewer stops on longer rides - a genuine plus for touring or a lengthy daily commute.
Low-maintenance final drive: Running Shaft drive (cardan) final drive cuts out the regular chain cleaning and tensioning that most bikes need.

Considerations

Age-related wear: Nothing specific stands out as a weak point on the R 65 - the usual used-bike checks (service history, consumables, tyres) apply.

Wear Points & Servicing Notes

Brake disc and pad wear

Braking up front comes from Single disc - solid stopping power, with disc and pad wear best checked on the same schedule as tyre changes.

Final drive maintenance

The R 65 uses shaft final drive: essentially maintenance-free day to day, with periodic gear-oil changes the only real service item.

R 65 - Buying & Maintenance Guide

What to check before buying

Before handing over money for a used 1981 BMW R 65, cover the fundamentals: service book and oil change history, chain and sprocket wear, and any sign of oil weeping around the casings. Cold-starting it yourself tells you a lot - a healthy R 65 should catch quickly and settle into a smooth idle.

Oil and filter changes

Nothing protects a R 65's engine like disciplined oil changes - stay on the manufacturer's schedule (roughly every 6,000 km or annually). Match the viscosity grade to what the owner's manual specifies, not what's cheapest.

1981 BMW R 65 - Frequently Asked Questions

What engine does the 1981 BMW R 65 have?

The 1981 BMW R 65 uses a Two cylinder boxer engine with 649 cc of displacement.

What is the top speed of the 1981 BMW R 65?

The 1981 BMW R 65 has a factory-quoted top speed of 175 km/h. Real-world speeds vary depending on rider weight, conditions and state of tune.

How much does the 1981 BMW R 65 weigh?

The 1981 BMW R 65 weighs 204 kg. This is the manufacturer's wet figure.

What is the fuel tank capacity of the 1981 BMW R 65?

The 1981 BMW R 65 has a 22-litre fuel tank. At around 5-6 litres per 100 km, that is roughly 366-440 km between stops.

What brakes does the 1981 BMW R 65 have?

The 1981 BMW R 65 uses Single disc at the front and Expanding brake at the rear.

What tyre sizes does the 1981 BMW R 65 use?

The 1981 BMW R 65 runs 3.25-18 front and 4.00-18 rear tyres. A good selection of sport, touring and all-weather rubber is available in these sizes.

What is the compression ratio of the 1981 BMW R 65?

The 1981 BMW R 65 runs a compression ratio of 9.2:1. Always use the minimum octane rating specified in the owner's manual.

BMW R 65 Spec Evolution

The BMW R 65 was produced across 14 model years (1979-1992). 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	1979	1980	1981	1982	1983	1984	1985	1986	1987	1988	1989	1990	1991	1992
Wet Weight	210 kg / 463 lbs	210 kg / 463 lbs	204.0 kg / 449.7 lbs	204.0 kg / 449.7 lbs	204.0 kg / 449.7 lbs	204.0 kg / 449.7 lbs	205.0 kg / 451.9 lbs	205.0 kg / 451.9 lbs	205.0 kg / 451.9 lbs	205.0 kg / 451.9 lbs	205.0 kg / 451.9 lbs	205.0 kg / 451.9 lbs	205.0 kg / 451.9 lbs	205.0 kg / 451.9 lbs
Engine Type	-	Two cylinder boxer	Two cylinder boxer	Two cylinder boxer, four-stroke	Two cylinder boxer, four-stroke	Two cylinder boxer, four-stroke	Two cylinder boxer	Two cylinder boxer, four-stroke	Two cylinder boxer	Two cylinder boxer	Two cylinder boxer	Two cylinder boxer	Two cylinder boxer	Two cylinder boxer
Top Speed	-	175.0 km/h / 108.7 mph	175.0 km/h / 108.7 mph	175.0 km/h / 108.7 mph	175.0 km/h / 108.7 mph	175.0 km/h / 108.7 mph	178.0 km/h / 110.6 mph	178.0 km/h / 110.6 mph	178.0 km/h / 110.6 mph	178.0 km/h / 110.6 mph	147.0 km/h / 91.3 mph	147.0 km/h / 91.3 mph	147.0 km/h / 91.3 mph	147.0 km/h / 91.3 mph
Fuel Capacity	22 Litres / 5.8 US gal	22 Litres / 5.8 US gal	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons	22.00 litres / 5.81 gallons
Brakes - Rear	Drum	Drum	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake	Expanding brake
Final Drive	Shaft	Shaft	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)	Shaft drive (cardan)
Compression Ratio	9.2:1	9.2:1	9.2:1	9.2:1	9.2:1	9.2:1	8.7:1	8.7:1	8.7:1	8.7:1	8.4:1	8.4:1	8.4:1	8.4:1
Tyres - Front	3.25 -18	3.25 -18	3.25-18	3.25-18	3.25-18	3.25-18	90/90-18	90/90-18	90/90-18	90/90-18	90/90-18	90/90-18	90/90-18	90/90-18

Key Specifications

Engine

Two cylinder boxer

Power

Not published by manufacturer

Torque

Not published by manufacturer

Top Speed

175.0 km/h / 108.7 mph

Weight

204.0 kg / 449.7 lbs

Fuel Capacity

22.00 litres / 5.81 gallons

Full 1981 BMW R 65 Specifications

Fuel Capacity 22.00 litres / 5.81 gallons

Wet Weight 204.0 kg / 449.7 lbs

Top Speed 175.0 km/h / 108.7 mph

Bore x Stroke (in,) 3.2 x 2.4 inches

Bore x Stroke (mm) 82.0 x 61.5 mm

Displacement (cc) 649.00 cc

Displacement (ci) 39.60 cubic inches

Engine Type Two cylinder boxer

Fuel Control OHV

Stroke 4

Compression Ratio 9.2:1

Valve System 2

Final Drive Shaft drive (cardan)

Gearbox 5-speed

Brakes - Front Single disc

Brakes - Rear Expanding brake

Tyres - Front 3.25-18

Tyres - Rear 4.00-18

Specifications are compiled from manufacturer documentation and cross-referenced technical sources, and corrected on an ongoing basis. Spot an error? Let us know.