Reliability is important with motorbikes, and the BMW ‘/5’ series certainly delivered in terms of performance. The series featured the R50/5, R60/5 and R75/5. Despite only being made between 1970 and 1973, all three motorbikes were incredibly advanced for their time and should be appreciated together. We’re looking into each model to see what made them so appealing.
Creating the R50/5
Former Porsche designer Hans-Gunther von der Marwitz was tasked with creating the first /5 series motorbike. He wanted to follow in the tradition of racer Rudolf Schleicher and design a machine that was fast and reliable. He developed a vehicle that featured a one-piece forged crankshaft, duplex chain and three-phase 180-watt automatic alternator that powered a revolutionary electrical system. The suspension made use of the BMW /2’s Fichtel & Sachs leading-axle telescopic forks.
The motorbike also came with a new double-loop frame that was designed for solo riding. Von der Marwitz decided that too much frame stiffness would negatively affect the performance. Despite the R50/5 being called a ‘rubber cow’ for its short swingarm, it didn’t prevent the motorbike from being a crowd-pleaser. The R50/5 was practical because it was lightweight.
In 1970, the R50/5 was released alongside the R60/5 and R75/5. Each model came with different engine sizes and slightly different configurations.
The R60/5 had a 600 cc engine and 38 mm and 34 mm valves. It could reach a top speed of 99 mph.
The R75/5 is considered the best motorbike in the series because of its 750 cc engine. It could reach a top speed of 110 mph. The engine offered a number of advantages over single-cylinder motorbikes, such as the low centre of gravity that provided improved handling. It also came with an electric power motor and 32 mm Bing CV carburettors.
By 1973, a total of 68,956 /5 series motorbikes had been produced. In 1974, BMW introduced the ‘/6’ model with revised instrumentation and a five-speed transmission. The influence of the /5 series can’t be understated because the world was introduced to a new form of motorbike with advanced technology.
Image Credit – https://commons.wikimedia.org/wiki/File:BMW-R75-01.jpg