The K800 flat four was the apogee of Zündapp’s model lineup, and is undoubtedly one of the world’s great motorcycles.
1938 Zündapp K800
Engine: 797cc air-cooled sidevalve horizontally opposed 4-cylinder, 62mm x 66.6mm bore and stroke, 5.8:1 compression ratio, 22hp @ 4,300rpm (at rear wheel)
Top speed: 75mph (60mph w/sidecar)
Carburetion: Single 22mm Amal (German)
Transmission: 4-speed, hand-shift, shaft final drive
Electrics: 6v, Bosch distributor w/coil and breaker points ignition
Frame/wheelbase: Pressed steel duplex cradle/55.1in (1,400mm)
Suspension: Pressed steel girder fork front, rigid rear
Brakes: 7.5in (190mm) SLS drum front and rear
Tires: 3.25 x 19in front, 3.5 x 19in rear
Weight (dry): 473lb (215kg)
Fuel capacity/MPG: 4gal (15ltr)/NA
Price then/now: NA/$6,000-$20,000
Before its sudden fall from favor in the 1970s, Zündapp was arguably Germany’s most successful motorcycle marque, and was certainly one of the pioneering brands in the European motorcycle industry. The K800 flat-four produced in the years before World War II was the apogee of its model lineup, and is undoubtedly one of the world’s great motorcycles.
Zündapp has become the forgotten brand in Germany’s two-wheeled history book. Yet after commencing bike production in 1922, it was for many years the country’s largest motorcycle manufacturer — albeit post-WWII in the western half only — and as recently as 1977 produced as many as 115,000 bikes in a single year, before sales of its by then predominantly 2-stroke range suddenly slumped in the face of Japanese competition, sending it just seven years later into the hands of the liquidator. But for over six decades Zündapp was at the forefront of the German motorcycle industry, and it surely ranks alongside BSA, Norton, Indian, Moto Guzzi, Triumph, Gilera and Harley-Davidson, as well as its BMW rival, as one of the most significant pioneer marques in two-wheeled history.
In the 1930s, Zündapp produced a pair of 4-cylinder K-series models — the “K” name tag denoting that they employed shaft final drive, or Kardanantrieb — with completely individual architecture, unlike their smaller-capacity brethren, which shared the same basic flat-twin layout as BMW’s boxer models.
1933 saw the debut of Zündapp’s first-ever horizontally opposed flat fours, the K600 and its range-topping K800 sister, both designed by Richard Küchen to feature his innovative design of 4-speed unit construction transmission, whereby sprockets and chains replaced the shafts and gear pinions of a more conventional gearbox. In solo form these positioned Zündapp at the top end of the market — its BMW rival never produced anything with more than two cylinders — while in sidecar guise they also allowed the company to offer models with much more power and especially more torque than were available elsewhere.
Order the November/December 2016 issue of Motorcycle Classics to read more about the 1938 Zündapp K800. Contact Customer Service at (800) 880-7567 or contact us by email