The BMW /2 Series

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Photo by Markus Hartel
Bill Costello on his restored 1958 BMW R50.

“If you want to be happy for a day, drink. If you want to be happy for a year, marry. If you want to be happy for a lifetime, ride a BMW.” That’s the copy from a 1965 ad for the BMW flat twin, commonly referred to as the Slash 2, or /2. Built by Bayerische Motoren Werke between 1955 and 1969, the machines were either a low compression 500cc R50, low compression 600cc R60, or, as introduced in 1956, a high compression R69. In reality, only the 1960-1969 officially carried the /2 designation. But as BMW guru Jeff Dean notes on his website, many owners commonly refer to the entire series as Slash 2s.

With its low compression 494cc flat twin, the R50 could be considered the base model of the BMW twin series for 1958. The twin, widely recognized for its smooth power delivery to the rear wheel via clean shaft drive, produced 26 horsepower. The next machine in the range, the R60, a 590cc flat twin, offered only two more horsepower from the mill for a total of 28.

The R69 was considered the hot rod of the line, rated at 35 horsepower from its 590cc, 8.0:1 compression ratio flat twin. In 1960 it was replaced with the R69S model, which upped the horsepower to 42 with even higher 9.5:1 compression.

The BMW gets its “boxer” moniker from its piston arrangement, with the pistons diametrically opposed and moving apart and together at the same time — legend holds the term was coined by Adolph Hitler, who, viewing a BMW engine factory, said the moving pistons reminded him of a boxer slapping his gloves together. And although one is on a compression stroke while the other is on an exhaust stroke, this allows the engine to remain fundamentally balanced.

By the time Richard Costello purchased his 1958 BMW R50 in 1961, BMW had made a strong impression on the motorcycling fraternity.

The machines were often considered the pinnacle of design and engineering; in remarkable contrast to the vast majority of machines on the market, its well-balanced and well-cooled flat twin seemed to be virtually oil tight under all conditions. This was a time when most machines marked their spot, wherever parked. And thanks to a swingarm rear suspension and an Earles front fork — a pivoted swingarm front suspension — the BMW offered an amazingly plush and stable ride.

With the leading-link Earles fork, the BMW has virtually no front brake dive. In fact, the nose of the bike is apt to rise with application of the front brake.

Period motorcycle magazine testers praised the BMW. In a 1955 road test, The Motor Cycle said: “Road behaviour of the R50 is extremely gentlemanly. Indeed, it is difficult to visualize a machine of conventional conception being more smooth, quiet, comfortable and clean to ride.”

That makes it easy to see how Richard covered some 60,000 miles aboard his 1958 R50, and why his son Bill is proud of the bike. He hopes the restored machine will be with one of his daughters in 40 years time. For now, though, both father and son, happy for a lifetime.

Read more about the BMW/2:

A Very Special 1958 BMW R50

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