TWN (Triumph Werke Nurnberg) German triumph bicycle of works AG, , Nurnberg. Siegfried Bettman a co-founder of the British Triumph motorcycles formed a subsidiary in Nurnberg, the "German Triumph bicycle Works AG" in 1896, and in 1903 like it's English partner began the production of motorcycles. In 1909 following a fall in demand for motorcycles they started production of the Triumph typewriters. By 1928/29 Triumph had become the third largest manufacturer with 13,500 units produced after DKW and Zuendapp, and in the year 1929, they separated from Triumph Coventry, and continued to develop and produce 350cc versions using Sachs and MAG 2 stroke engines. But due to legal arguments with Triumph UK the German Triumph models were exported under the Orial badge, and after protest from a French company of the same name they changed to "TWN" for Triumph of Works Nurnberg. Resuming production in 1948 after the II world war with a range of utility two-stroke split singles of 125cc to 350cc, some with rotary valves. They also branched into the production of moped and scooter models. In the autumn 1956 Triumph teamed up with Hercules and Eagle (Frankfurt) but production was however short lived and the company was taken over by Grundig in 1957, reverting to the manufacture of type-writers.
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TWN Bike Review
Cyclemotor 1953-57, 2-stroke,
belt or chain drive.
Bolt-on to a standard bicycle frame.
1956-57, 47cc 2-stroke,
1946-57, 123cc, 2-stroke single, 3 speed, 204lb
1953-57, 197cc, 2-stroke split single, 4 speed,
1946-57, 248cc, 2-stroke split single, 4 speed,
350 1953-57, 344cc, 2-stroke split single, 4 speed
1956, 125cc , 2-stroke.
1954-57, 197cc, 2-stroke split single, 4
The concept was adopted by Ing Zoller in 1931 and was to make DKW (Germany) the dominant racing motorcycle in the Lightweight and Junior classes during the pre war years.
The idea of a split single was to have the exhaust port open before the transfer ports then close before the transfer ports thus preventing loss of fresh charge out the exhaust. The traditional two-stroke engine allowed the charge to flow straight across the cylinder and out of the exhaust port with the exiting burnt gasses despite port angling and schnerle ports. This layout gave a smooth power delivery with no 'four stoking' and excellent high end performance. Good tractability from low revs and 20% improvement on fuel consumption.
A major draw back of the design was the mass of the pistons and con-rods when compared to a conventional single leading to vibration, which could also lead to other problems on the bike. Also high fuel consumption on high performance machines.
TWN also pioneered Aluminium barrels with dull chrome plating which was honeycombed with small indentations giving a better lubrication effect.
See also TWN-Zweirad-IG