| Quick Specs: BMW R 50/5 (0240) | |
|---|---|
| Production Years | 1969 – 1973 |
| Engine Oil | SAE 20W-50 Mineral (2.0 L) |
| Tires (F/R) | 3.25 S 19 / 4.00 S 18 |
| Tire Pressure (F/R) | 1.9 bar / 2.1 bar |
| Spark Plugs | NGK BP6ES / Bosch W7DC |
| Battery | 12V 18Ah (DIN 51814) |
The BMW R 50/5 represents a pivotal moment in motorcycling history; it was the first BMW motorcycle series to be produced entirely at the Berlin-Spandau plant following the relocation of production from Munich. This shift coincided with the introduction of the ‘Slash 5’ chassis, which moved away from the traditional Earles forks in favor of modern telescopic forks, forever changing the handling characteristics of the Bavarian boxer.
Engineering Overview
At the heart of the R 50/5 (Type 0240) is the 498cc air-cooled, four-stroke, horizontal twin ‘Boxer’ engine. While it was the entry-level model of the /5 series, it benefited from the same high-quality engineering as its larger siblings. The engine featured a high-mounted camshaft and a robust 12V electrical system, a significant upgrade from the 6V systems found on previous generations, ensuring better lighting and more reliable starting.
Maintenance & Technical Guidelines
To maintain the longevity of the R 50/5, adhering to specific fluid and component standards is essential for the modern collector and rider.
Lubrication System
The R 50/5 utilizes a pressure lubrication system. For optimal protection of the vintage internal components, SAE 20W-50 Mineral oil is the industry standard. This viscosity provides the necessary film strength for air-cooled tolerances. The total capacity is 2.0 Liters. Avoid modern synthetic oils with high friction modifiers as they may lead to seal weeping in older gasket materials.
Wheels and Tires
Proper tire maintenance is critical for the R 50/5’s stability. The factory specifies a 3.25 S 19 front and a 4.00 S 18 rear tire. For standard solo riding, maintain pressures at 1.9 bar (27.5 psi) in the front and 2.1 bar (30.5 psi) in the rear. Periodic checking of spoke tension is also recommended to ensure the integrity of the aluminum rims.
Ignition and Electrical
For consistent combustion, MotoSpecsLab recommends the NGK BP6ES or the Bosch W7DC spark plugs. The electrical system is powered by a 12V 18Ah battery (standard DIN 51814). Given the age of these machines, ensuring clean ground connections is the most effective way to prevent the common ‘charging’ issues associated with early Bosch alternators.
Editorial Verdict
The BMW R 50/5 – 0240 is more than a vintage motorcycle; it is a testament to the reliability of German engineering during the transition into the modern era of superbikes. While it lacks the raw power of the R 75/5, its smooth power delivery and balanced chassis make it one of the most rideable classics in the current market. Proper maintenance using mineral-based lubricants and correct tire pressures will ensure this machine remains roadworthy for decades to come.