The Fend Flitzer was a three-wheeled invalid carriage designed and built by Fritz Fend. The Flitzer established many of the basic concepts on which Fend's later microcars were developed.
In 1948, Fend, a former aeronatical engineer and technical officer in the Luftwaffe, began production of a tricycle invalid carriage in his workshop in Rosenheim, Germany. The tricycle had a front wheel that was steered by handlebars and powered by a mechanism actuated by pushing back and forth on the handlebars. Shortly afterward, it was offered with a 38 cc (2.3 cu in) Victoria two-stroke proprietary engine normally used for motorizing bicycles.
Fend then designed the Flitzer, a larger, better-enclosed invalid carriage. It was designed from the start to be powered by a gasoline engine. Whereas the earlier tricycle was both steered and powered by a single front wheel, the Flitzer had a pair of front wheels linked to the steering mechanism and a powered rear wheel.
The Flitzer was made with aluminium panels over a steel frame and was enclosed at the front, sides, and back. It had a hatch at the top that was hinged at the front and tilted forward for the operator to get in. The first version of the Flitzer was open, with a hole and a windshield in the hatch for the operator's head and shoulders to stick through and be protected from the wind. Flitzers made from September 1948 into 1950 were powered by a 98 cc (6.0 cu in) Fichtel & Sachs two-stroke engine. Suspension was by rubber springs loaded in torsion.
In 1950 the engine was changed to a 100 cc (6.1 cu in) Riedel/Imme engine. By 1951, in response to customer requests for passenger-carrying capability, a scooter-type saddle was placed above the rear enclosure with footrests on either side of the body. A closed version, on which the hatch had an enclosure that covered the operator, was made available. The enclosure included the windshield and side windows.