Renowned for its high- performance cars, BMW has long had trouble shaking the image that it's a builder of slightly quirky but sensible motorcycles for wealthy, bearded men.

That's not to say BMW didn't make efforts to combat this image as it watched Japan's motorcycle makers grow to dominate the industry. In the 1970s it even began offering its bikes in colors other than black.

When that didn't do the trick, BMW sought to move away from its iconic twin-cylinder boxer motor — first produced in 1923 — with the release of the K100 series in the early 1980s. These bikes sported BMW's first liquid-cooled four-cylinder motors. But their unusual design — the engine lay sideways in a tubular steel frame — and unexceptional performance did little to boost the motorcycle division's sporting image.