IThe Zundapp Citation was clearly a derivative of the Horex Imperator, and was reportedly only branded a Zundapp in order to work around the legal restrictions of the US importer Berliner Motors. The Imperator was a 400cc twin produced in the waning days of Horex before it was purchased by Mercedes (see Horex Motorcycles). The Zundapp version created an oversquare bore and stroke, and overhead cam to reach 452cc and to produce 40 hp. This was enough to market the it as a 500, and claim 100+ mph speeds. Not bad in 1958. It was named the Citation after the triple-crown winning horse.
Despite good quality, performance, and design, timing could not have been worse. The bike was introduced into the teeth of a worldwide recession. On top of that, a series of marketing and legal issues impacted sales in the important US market. The Citation was limited to a 2 year life span from 1958 to 1960.