Racer and restorer Bo Neilsen is a bonafide expert on little-known Nimbus motorcycles. So much so that YouTube’s Classic Motorcycle Channel rewards its audience with a deeper look at Neilsen’s 1947 Nimbus 750 Sport sand racer. From its Erector Set-like frame to its throaty exhaust note, Neilsen’s Nimbus—and all Nimbuses, for that fact—remain in a class of its own.

No one knows Nielsen’s hot-rodded sand racer like the man himself. For that reason, we’ll leave the explaining to him. For those unfamiliar with the brand, however, come with us for a skip down memory lane.

In 1910, H.M. Nielsen and Peder Andersen Fisker founded Nilfisk, an electric motor and vacuum cleaner producer. Fisker embarked on an entirely new endeavor in 1918, though. That’s when Nimbus was born. Developing an all-new motorcycle prototype, the Danish entrepreneur did things his own way.

That included a 746cc, longitudinal inline-four. The model’s shaft drive departed from convention too. There's nothing more distinctive than where that unique drivetrain resided: a flat steel frame. The Type A and Type B models were the result, debuting in 1919 with 10 horsepower and a 53-mph top speed. Unfortunately, the model’s construction earned it the nickname "Stovepipe", a monicker Fisker himself scorned.

Economic factors forced the company to wrap production on the Stovepipe by 1926. The second time around proved more fruitful for Fisker. With the help of his son, Anders Fisker, the Nimbus co-founder returned to the drawing board, designing a new platform in 1932.

The Type C arrived by 1934. Nimbus’ signature shaft drive and flat steel frame returned, but the longitudinal inline-four earned a new overhead valve and overhead cam layout. Those improvements spurred the cruiser onto 18 horsepower (22 horsepower on later models) and a 75-mph top speed.

Like Harley-Davidson's rise in the U.S., Nimbus didn’t just sell well with consumers but also benefitted from Post Office, Army, and Police contracts. The Danish government alone spent kr. 50M (~$7.3M USD) to modernize the Army’s fleet with Type Cs. The firm's military contract represented nearly 20 percent of its production. As a result, Nimbus failed to introduce new models due to the accessories and parts inventory required for such a platform.

The Type C was just as prevalent within the civilian world. Many police departments didn’t phase out their units until the early ‘60s while the post office continued utilizing the model until 1972. While Nimbus found mass adoption in Denmark, it decided against exporting the Type C. Still, collectors the world over, such as Bo Neilsen, covet the Dainish two-wheeler. And, now we know why.

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