1985 BMW R 80G/S Specifications

Name: 1985 BMW R 80G/S
Brand: BMW

All-Round • Specs last verified 13 July 2026

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1985 BMW R 80G/S Overview

The 1985 BMW R 80G/S is an all-round motorcycle built around 797 cc of displacement. Under the tank sits a Two cylinder boxer engine running OHV valve actuation, a compression ratio of 8.2:1. The bore and stroke measures 84.8 x 70.6 mm. 1985 BMW R 80G/S delivers. The factory-quoted top speed stands at 173 km/h, making it a capable performer in its class. From a practical standpoint, the 1985 R 80G/S tips the scales at 196 kg and carries a 19.50-litre fuel tank. That's roughly 6.9 kg heavier than the average all-round motorcycle in our database. Scroll down for the complete 1985 BMW R 80G/S spec sheet covering every technical detail from suspension travel to tyre sizes.

1985 BMW R 80G/S compared with other bikes in the All-Round category

Here is how the 1985 BMW R 80G/S stacks up against other bikes in the All-Round category in our database. Each model counts once, using the model year closest to this one, and the comparison covers up to 497 models.

Engine displacement of 797 cc is larger than that of 349 of the other 496 bikes in the All-Round category.
Only 71 of the other 187 bikes in the All-Round category have a higher top speed than the 173 km/h of the R 80G/S.
Narrowing the field to the 117 models within five model years of it, the engine displacement of 797 cc is larger than that of 89 of the other 116.

Versus the 1983 model

Compared with the 1983 model, wet weight increased from 186 kg to 196 kg (+10 kg) and top speed climbed from 167 km/h to 173 km/h (+6 km/h). Displacement is unchanged.

1985 R 80G/S - Pros & Cons

Strengths

Strong front braking: The single disc front brake gives excellent stopping power and responds well to aftermarket braided lines.
Large fuel range: The 19.50-litre tank is generously sized, translating to extended range between stops - ideal for touring or longer commutes.
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

Age-related wear: As with any used R 80G/S, a thorough pre-purchase inspection covering consumables, service history and tyres is always recommended.

Wear Points & Servicing Notes

Brake disc and pad wear

The single 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.

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.

R 80G/S - Buying & Maintenance Guide

What to check before buying

When inspecting a used 1985 BMW R 80G/S with its 797 cc all-round, 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 41 years old, this all-round 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 80G/S 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 80G/S's 797 cc two cylinder boxer. Stick to the manufacturer's interval - typically every 6,000 km or once a year, whichever comes first. With an 8.2:1 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.

1985 BMW R 80G/S - Frequently Asked Questions

What engine does the 1985 BMW R 80G/S have?

The 1985 BMW R 80G/S uses a Two cylinder boxer engine with 797 cc of displacement.

What is the top speed of the 1985 BMW R 80G/S?

The 1985 BMW R 80G/S has a factory-quoted top speed of 173 km/h. Real-world speeds vary depending on rider weight, conditions and state of tune.

How much does the 1985 BMW R 80G/S weigh?

The 1985 BMW R 80G/S weighs 196 kg. This is the manufacturer's wet figure.

What is the fuel tank capacity of the 1985 BMW R 80G/S?

The 1985 BMW R 80G/S has a 19.50-litre fuel tank. At around 5-6 litres per 100 km, that is roughly 325-390 km between stops.

What brakes does the 1985 BMW R 80G/S have?

The 1985 BMW R 80G/S uses single disc at the front and Expanding brake at the rear.

What tyre sizes does the 1985 BMW R 80G/S use?

The 1985 BMW R 80G/S runs 3.00-21 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 1985 BMW R 80G/S?

The 1985 BMW R 80G/S runs a compression ratio of 8.2:1. Always use the minimum octane rating specified in the owner's manual.

BMW R 80G/S Spec Evolution

The BMW R 80G/S was produced across 7 model years (1980-1987). 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	1980	1981	1982	1983	1985	1986	1987
Wet Weight	186 kg / 409 lbs	186 kg / 409 lbs	186 kg / 409 lbs	186 kg / 409 lbs	196.0 kg / 432.1 lbs	196.0 kg / 432.1 lbs	196.0 kg / 432.1 lbs
Engine Detail	Four stroke, two cylinder horizontally opposed Boxer, pushrod operated 2 valves per cylinder.	Four stroke, two cylinder horizontally opposed Boxer, pushrod operated 2 valves per cylinder.	Four stroke, two cylinder horizontally opposed Boxer, pushrod operated 2 valves per cylinder.	Four stroke, two cylinder horizontally opposed Boxer, pushrod operated 2 valves per cylinder.	-	Four stroke, two cylinder horizontally opposed Boxer, pushrod operated 2 valves per cylinder	-
Engine Type	Two cylinder boxer, four-stroke	-	Two cylinder boxer, four-stroke	Two cylinder boxer	Two cylinder boxer	Two cylinder boxer	Two cylinder boxer
Top Speed	167 km/h / 104 mph	167 km/h / 104 mph	167 km/h / 104 mph	167 km/h / 104 mph	173.0 km/h / 107.5 mph	167 km/h / 104 mph	173.0 km/h / 107.5 mph
Fuel Capacity	19.5 L / 5.1 US gal	19.5 L / 5.1 US gal	19.5 L / 5.1 US gal	19.5 L / 5.1 US gal	19.50 litres / 5.15 gallons	19.5 Litres / 5.1 US gal	19.60 litres / 5.18 gallons
Displacement	797.5 cc / 48.7 cu in.	797.5 cc / 48.7 cu in.	797.5 cc / 48.7 cu in.	797.5 cc / 48.7 cu in.	-	797.5 cc / 48.7 cu-in	-
Brakes - Front	Single ∅260mm disc	Single ∅260mm disc	Single 260mm disc	Single ∅260mm disc	Single disc	Single disc	Single disc
Brakes - Rear	∅200mm Drum	∅200mm Drum	200mm Drum	∅200mm Drum	Expanding brake	200mm Drum	Expanding brake

Key Specifications

Engine

Two cylinder boxer

Power

Not recorded

Torque

Not recorded

Top Speed

173.0 km/h / 107.5 mph

Weight

196.0 kg / 432.1 lbs

Fuel Capacity

19.50 litres / 5.15 gallons

Full 1985 BMW R 80G/S Specifications

Fuel Capacity 19.50 litres / 5.15 gallons

Wet Weight 196.0 kg / 432.1 lbs

Top Speed 173.0 km/h / 107.5 mph

Bore x Stroke (in,) 3.3 x 2.8 inches

Bore x Stroke (mm) 84.8 x 70.6 mm

Displacement (cc) 797.00 cc

Displacement (ci) 48.63 cubic inches

Engine Type Two cylinder boxer

Fuel Control OHV

Stroke 4

Compression Ratio 8.2:1

Valve System 2

Final Drive Shaft drive (cardan)

Gearbox 5-speed

Brakes - Front Single disc

Brakes - Rear Expanding brake

Tyres - Front 3.00-21

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.