| Specification | Data |
|---|---|
| Production Years | 1982 – 1984 |
| Engine Oil | SAE 20W-50 Mineral (2.25 L) |
| Tires (Front/Rear) | 100/90-19 57H / 120/90-18 65H |
| Tire Pressure (F/R) | 1.9 bar (27.5 psi) / 2.1 bar (30.5 psi) |
| Battery | DIN 516 15 |
| Spark Plug | Bosch W7DC (0.6 mm gap) |
While the R 80 G/S is often credited with birthing the Adventure category, its road-going sibling, the BMW R 80 ST (Type 0347), holds a unique engineering distinction: it was the first BMW to prove that the revolutionary Monolever single-sided swingarm was not just for off-road utility, but for superior street handling and simplified maintenance.
Engineering Overview
The R 80 ST was BMW’s response to riders who desired the agility and lightweight nature of the G/S but preferred the asphalt. By utilizing the 797cc air-cooled boxer engine, BMW delivered a smooth 50 hp output. The transition from G/S to ST involved shortening the front suspension travel and fitting a 19-inch front wheel, which significantly sharpened the steering geometry compared to the 21-inch off-road counterpart.
Technical Maintenance Guide
Lubrication System
For the Type 0347 engine, SAE 20W-50 Mineral oil is mandatory. Modern synthetics are often too thin for the tolerances of this vintage boxer, potentially leading to increased consumption or leaks. The system capacity is 2.25 liters. We recommend changing the oil filter every 7,500 km to preserve the integrity of the crankshaft bearings.
Ignition and Electrical
The ignition system relies on Bosch W7DC spark plugs. Critical to smooth idling is the electrode gap, which must be set precisely to 0.6 mm. The electrical system is supported by a DIN 516 15 battery; ensure terminal connections are clean to prevent the common ‘click-no-start’ issue prevalent in aged Bosch starter solenoids.
Chassis and Tires
The handling characteristics of the ST are highly sensitive to tire pressure. Maintain 1.9 bar (27.5 psi) in the front 100/90-19 tire and 2.1 bar (30.5 psi) in the rear 120/90-18 tire. Deviating from these pressures can lead to ‘head shake’ at higher speeds due to the bike’s lightweight front end.
MotoSpecsLab Verdict
The BMW R 80 ST is a masterclass in ‘less is more.’ With only 5,953 units produced, it is a rare collector’s item that offers a more refined, vibration-damped ride than the R 100 models of the same era. Its mechanical simplicity makes it an ideal candidate for DIY enthusiasts who value the tactile nature of a classic airhead.
FAQ
Q: Can I use 10W-40 oil?
A: It is not recommended. The air-cooled boxer engine operates at higher temperatures; 20W-50 mineral oil provides the necessary viscosity film strength.
Q: Is the R 80 ST parts-compatible with the R 80 G/S?
A: Most engine and drivetrain components are identical, but the front forks, wheel size, and instrumentation are specific to the ST model.