The Nimbus is a Danish motorcycle produced from 1920 to 1957 by Fisker and Nielsen (Copenhagen, Denmark), also known as manufacturer of Nilfisk vacuum cleaners.
Two basic models were produced, both had 750 cc in-line four cylinder engines and shaft drive.
The first was made during the 1920s and had both front and rear wheel springing and a very characteristic spine frame giving birth to its nickname "The Stovepipe".
The later model "The bumblebee" was produced in very large numbers from 1934 till the end. It had a ohv-design engine and a frame made from steel bar. Also it had one of the earliest telescopic front forks seen - possibly the first? A very reliable and sturdy motorcycle often seen attached to a sidecar. Many of them served the post, military, police and other official duties in Denmark. Few were exported when new.
Eventually the design grew old-fashioned and as interest in motorcycles turned down in the late 1950s - as a consequence of the availability of cheap cars such as the Volkswagen, VW - production ceased after some work to develop new models (a four cylinder with a rotary valve and a two cylinder - both never reached production).