| Attribute | Specification |
|---|---|
| Model Code | 0302 |
| Production Years | 1976-1977 |
| Engine Type | Air-cooled, 2-cylinder Boxer |
| Engine Oil | SAE 20W-50 API SF/SG Mineral (2.25 L) |
| Spark Plug | Bosch W7DC |
| Tire Size (Front) | 3.25 S 19 |
| Tire Size (Rear) | 4.00 S 18 |
| Tire Pressure (F/R) | 1.9 bar / 2.1 bar |
| Battery | 12V 28Ah (DIN 52816) |
The BMW R 75/7, specifically the internal designation 0302, represents a pivotal moment in BMW Motorrad history. While previous generations utilized the iconic ‘toaster’ tanks and rounded aesthetics, the /7 series introduced in 1976 debuted the more angular, ‘slab-sided’ fuel tank and integrated instrumentation that would define the brand’s touring identity for the next decade. This model was the final evolution of the 750cc boxer before BMW pivoted toward the 800cc displacement for its mid-range airheads.
Engineering & Performance Analysis
The R 75/7 is powered by a 745cc overhead valve (OHV) horizontally opposed twin. Producing approximately 50 horsepower, it struck a perfect balance between the nimble handling of the smaller R 60/7 and the heavy-set cruising nature of the R 100/7. The 0302 variant benefited from the transition to a five-speed gearbox, providing a significantly smoother highway experience compared to the earlier four-speed units.
Maintenance Guidelines
For the preservation of the boxer engine’s longevity, adherence to specific lubricant standards is non-negotiable. At MotoSpecsLab, we emphasize the use of high-quality mineral oils to protect the flat-tappet cam followers.
Lubrication System
The engine requires 2.25 liters of SAE 20W-50 API SF/SG Mineral oil. Modern synthetic oils with high detergent levels are often discouraged for these vintage seals; a high-zinc (ZDDP) mineral content is preferred to prevent premature wear on the valvetrain.
Ignition and Electrical
The 0302 utilizes Bosch W7DC spark plugs. Given the 12V 28Ah battery capacity (DIN 52816), the electrical system is robust enough for long-distance touring, provided the charging system (stator and diode board) is regularly inspected for heat-related fatigue.
Chassis and Tires
Handling characteristics are highly dependent on maintaining the specific tire pressures of 1.9 bar (Front) and 2.1 bar (Rear). Using the period-correct 3.25 S 19 and 4.00 S 18 sizing ensures the geometry remains as intended by the Munich engineers, preventing the ‘high-speed weave’ sometimes reported with modern oversized rubber.
Conclusion
The BMW R 75/7 (0302) remains one of the most balanced ‘Airheads’ ever produced. It offers the classic aesthetic of the 1970s with the mechanical refinements of the later series, making it an ideal candidate for both collectors and vintage touring enthusiasts.