Triumph TWN

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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1937 TWN B200E 200cc	1939 TWN BD250 250cc	1954 TWN Boss 350cc
1955 TWN Cornet 197cc		1955 TWN Fips 50cc

TWN Bike Review

Knirps Cyclemotor 1953-57, 2-stroke, belt or chain drive.
Bolt-on to a standard bicycle frame.

Fips 1956-57, 47cc 2-stroke,
Built using a Sachs engine, trailing link front forks, swinging arm rear suspension, full width front hub.

BDG125 1946-57, 123cc, 2-stroke single, 3 speed, 204lb
Based on the pre-war model BD125 using the split single two-stroke engine design. 1949 telescopic forks added. 1950 the H model incorporated plunger rear suspension. 1954 model L

Cornet 1953-57, 197cc, 2-stroke split single, 4 speed, 266lb, 63mph
Built to celebrate the Golden Jubilee of 50 years, with full swinging arm rear suspension, oil damped front forks and a new sturdy frame. Single foam rubber seat, with companion seat as optional and was bolted to the mudguard. 1956 12V electrics and neutral selector from any gear.

BDG250 1946-57, 248cc, 2-stroke split single, 4 speed, 303lb, 63mph
Based on the pre-war model BD250 using the split single two-stroke engine design, dual exhaust and enclosed chain case. 1949 telescopic forks added. 1951 the H model adopting plunger rear suspension and shorter stroke redesigned engine. 1953 two new models replacing the H, was the L which was less powerful and heavier at 321lbs with deep valance mudguards and the S a sportier model with narrow mudguards, less weight and better performance. Both carried a single bulbous expansion chambered exhaust.

Boss 350 1953-57, 344cc, 2-stroke split single, 4 speed
Based on a traditional tubular chassis, single front down tube with plunger rear suspension and telescopic front forks. Using the split single two-stroke engine design, dual bulbous exhaust forming expansion chambers, twin carbs, hydraulic rear brake with master cylinder built into the engine crankcase, rear stop light, full width hubs and enclosed chain case.

Tessy 1956, 125cc , 2-stroke.
A scooter which was a dismal failure and had a very short production life.

Contessa 1954-57, 197cc, 2-stroke split single, 4 speed
Scooter based on the Cornet motor with fan cooling, 12V electrics and electric start. Leading arm front fork and swinging arm rear suspension.

Split Single Engine

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.