Wearing ‘Airhead’ as a Badge of Pride

Long before the term “platform” became popular to describe a single vehicle chassis that underpins many different models, BMW Motorrad had perfected the concept. From 1970 to 1996, the company, famous for its high quality mile-gobbling bikes, offered one of motorcycling’s most diverse ranges: six standard roadsters from 500 cc to 1,000 cc, with sport, touring and even dual-sport versions, all based on a common set of components.

With their smooth and torquey power delivery, fuss-free driveshafts, plush suspensions and stout construction, these “airhead” BMW twins – that’s a term of endearment for the air-cooled models – are capable of effortlessly covering hundreds of miles per day, year after year.  Their inherent simplicity compared with bikes with more cylinders (or even BMW’s later oil-cooled twins) make them easy to maintain, modify and restore.

They are ideal practical classics that also have become a favorite of custom and café motorcycle builders as well as vintage racers.

“Anyone wanting a reliable classic to ride or customize can get a BMW airhead fairly cheap, whereas a nice Triumph or Honda CB750 is going to be equal or more money,” said John Landstrom, owner of Blue Moon Cycle in Norcross, Ga., which specializes in vintage BMWs. “And parts availability is excellent.”

Known to Beemerphiles as the slash-5 (1970-73), slash-6 (1974-76) and slash-7 (1977-96) series, the horizontally opposed two-cylinder engines shared a 70.6-mm crankshaft stroke. Successively larger cylinder bores were used to step up displacement from the mild 500 cc R50/5 to the full-liter R100/7. The series ended in 1996 with the R100R Mystic and Classic, tribute models wearing the single-shock Paralever rear suspension introduced in 1987.

In between were R60 (600 cc), R75 (750 cc), R80 (800 cc) and R90 (900 cc) models in various forms. Pacesetters among them included the R90S, BMW’s first superbike; the R80G/S (the letters in German stand for off-road/street) that pioneered the “adventure bike” trend; and the flagship R100RS sport-tourer and R100RT full-dress tourer

According to Landstrom, the airhead twins remain somewhat undervalued because many still consider them just used motorcycles rather than collectibles. “When they were new, they typically appealed to older, more conservative riders who owned them for decades,” he said.

While values have been rising, $3,000 to $4,000 will get you a pretty nice standard roadster if you look around. “But in that price range they’re going to have at least 50,000 miles on them,” he explained. “They may have been repainted.”

Original-condition, low mileage and clean /5 and /6 models—the latter featuring BMW’s first front disc brakes and 5-speed gearbox –are in the $7,500 range, Landstrom said. The most collectible airhead models are led by the hot-rod R90S, originally sold in 1973-76. While good ones can be found for under $12,000, Landstrom noted, pristine factory-correct examples in the desirable Daytona Orange paintwork have recently touched $15,000.

Other blue chip models from the /5 through /7 era include the R75/5, with its four-gallon chrome-sided gas tank – the so-called “toaster” – that polarized customers in 1972-73 but is now considered a cool feature, and the limited-production Paris-Dakar Edition of the 1984 R80 G/S, complete with enormous 8.4-gallon tank and solo saddle.

For vintage bike enthusiasts – or those just wanting a trustworthy machine to ride – there are few if any classic machines that are more practical to own than a /5 through /7 BMW. “No other older bike will give you less headaches,” asserted Landstrom, who this summer will be riding his slash-5 from Georgia to the BMW National Rally in upstate New York, about 900 miles each way.

BMW /5, /6, /7 airhead twins
Years sold in U.S.: 1970-95
Engine type: Air-cooled OHV horizontally-opposed 4-stroke twin, single camshaft and 2 valves per cylinder

Gearbox: 4-speed (1970-73), 5-speed (1974-95)
Horsepower rating:
36 (R50)
46 (R60)
57 (R75)
55 (R80)
67.5 (R90)
72 (R90S)
60 (R100)
70 (R100RS)

Top speed: 90 mph (R50) to 125 mph (R100RS)

Weight (dry): 410 lb (R50) to 515 lb (R100RT)

Price new: ranging from $1,425 (1970 R50/5) to $7,250 (1996 R100R)

Price 2016: ranging from $2,500 (R60/5 in restorable condition) to $15,000 (mint R90S)