BMW R 850 R – 259R Maintenance: Recommended Oil & Tires

While the larger R 1100 R often dominated the headlines of the 1990s, the BMW R 850 R (259R) is widely considered by BMW engineers and purists to be the most refined iteration of the early ‘Oilhead’ generation. Due to its shorter stroke and smaller pistons, the 850cc engine generates significantly fewer secondary vibrations than its larger sibling, offering a smoothness that defines the ‘sweet spot’ of the 259-series chassis.

Technical Overview: Engineering the 259R

The R 850 R was a pivotal model for BMW, introducing the Telelever front suspension and Paralever rear swingarm to a broader audience. These systems decoupled braking forces from suspension movement, virtually eliminating front-end dive—a characteristic that remains a hallmark of BMW’s touring DNA. The engine utilizes a high-camshaft design with short pushrods, allowing for better cooling and higher RPM stability compared to traditional OHV designs.

Maintenance Essentials

Lubrication System

For the air/oil-cooled boxer, thermal stability is critical. MotoSpecsLab recommends SAE 20W-50 mineral or semi-synthetic oil. The higher viscosity is essential for maintaining oil pressure and providing a cushion for the engine’s internal tolerances. The system capacity is 3.75 liters including the filter change.

Chassis and Tires

The 259R utilizes a 17-inch wheel setup both front and rear, which opens up a wide variety of modern sport-touring rubber. Maintaining correct pressure is vital for the Telelever’s feedback. For solo riding, 2.2 bar (front) and 2.5 bar (rear) is standard, increasing to 2.5 bar and 2.9 bar respectively when carrying a passenger or heavy luggage.

Electrical and Ignition

Reliable starting depends on the DIN 51913 (12V 19Ah) battery. Given the high compression of the boxer engine, a healthy battery is required to overcome the initial resistance of the starter motor. For ignition, the dual-electrode Bosch FR 6 DDC or NGK BKR7EKC are the factory-specified plugs, designed to ensure a consistent flame front across the combustion chamber.

Editorial Verdict

The BMW R 850 R is more than just a ‘budget’ version of the 1100. It is a precision instrument that offers better fuel economy, lower insurance rates, and a more linear power delivery. For the modern collector or commuter, it represents a peak of mechanical accessibility before the introduction of complex CAN-bus electrical systems in later generations.