The new NZ series of motorcycles was announced with two new models, a 250cc and a 350cc, for the first time in the DKW dealers bulletin of 28. Dec 1937. In the bulletin from 28 March 1938 the factory once again announced the launch of these new models and than the first NZs leave the factory in November 1938.
In this period the factory already experienced some problems with the lack of materials therefore the earlier announced features of the bikes as side-crutch and chain-box were not mounted on the first bikes. The chain-box was never adopted in this series.
Initially it was planned that the sides of the gastank should be chrome plated. Shortly before the launch of the new models on the Berlin Kaiserdamm-Exibition in February 1938 the use of chrome on motorcycle tanks was banned. DKW then decided to spray the sides of the gastank with melted aluminium, which was then polished.
The new NZ series was the result of years of long technical research and innovations in the DKW's research centre. New revolutionary pressed-steel mainframe - Zentralkastenrahmen, more beautiful engine block, four speed gearbox, new starter mechanism, are the main characteristic features of this new civil motorcycle. The mainframe itself was a masterpiece of engineering: made from two pressed steel sheets which were electrically welded together. Unfortunately the welding process used so much electricity, that the welding could only be done at night, when the electrical consumption of the other parts of town were lower.
Initially it was planned to supply the NZ with a rear suspension. Extensive tests were made and a suspension was chosen which was already patented by the Italian manufacturer Benelli. When it became clear that royalties had to be paid to Benelli, the rear suspension had to be omitted for costing reasons. Nevertheless about 1100 NZ's were supplied with that rear suspension, but were only supplied to the government organisation NSKK. At the end of 1938 also an "offroad version" of the NZ was available for a price increase of 40,00 RM. These bikes were fitted with a raised exhaust system, axles with "quickchange" handles, the dynamo guard, but not with offroad tyres!
From 1939 on NZ was also available in a version for the government, which later became the NZ 350/1943 and finally the NZ350-1.
In June 1940 the rear end of the bike was shortened with 40 mm (from frame number 582559), which lifted the rear seat with 4 mm.
In the beginning the central electric box was of type Sp12A, which had the ignition key hole blanked, it was replaced in the beginning of 1943 by the new type Sp12R. There were two types of exhaust systems mounted - Eberspaecher and Leistritz. The latter was recognisable for the wider fish-tail end. The DKW build Framo seat was used alongside with the new Pagusa type. There were two types of ignition switches mounted - the switch of the HASAG company had a longer cast metal key were the Hella one, used from end 1939 owards too, had a pressed-metal key.
In early 1941 the production of the NZ250 stopped. The NZ350 continued to be build for Wehrmacht use only (from VIN 595200 onwards only NZ350's were build). At the same time the gearbox was reinforced and the gear-ratio was changed to facilitate driving at low speeds in a convoy. The reinforced gearbox can be identified by the letters VG "verstaerktes Getriebe" on the engine case from engine number 1180601.
During the war the production of the company was restricted from the spectrum 125 - 500 cc of different types to just two models - NZ 350/NZ 350-1 and RT 125. The NZ 350 was adopted for army service and became the "middle-class 350 cc motorcycle" in the Wehrmacht's catalogue. In the company's catalogue it was known as NZ 350-1.