1957 Triumph TWN BDG125L
Claimed power: 6.7hp @ 5,200rpm
Top speed: 50mph
Engine: 123cc 2-stroke, air-cooled split-single
Weight (wet): 227lb (103kg)
Fuel capacity/MPG: 12ltr (3gal) / 100mpg (claimed)

Ever heard of a Triumph Cornet? Triumph Boss? Triumph Tessy? A 1957 Triumph TWN BDG125L? They’re all names of once-popular motorcycles (and one scooter), but unless your last name’s Schmidt, Schmiedeler or Schottenhauser, it’s doubtful any of these names ring a bell.

In the early 1950s, the German motorcycle market was among the world’s biggest, and it was crowded. In 1953, German factories produced 437,000 motorcycles, made by companies like Ardie, BMW, Zundapp, DKW, Maico, Victoria and Triumph Werke Nuremberg, or TWN.

The beginning
You’re probably asking yourself, "Wasn’t Triumph an English company?" The answer is yes, and no. The founder of Triumph was German-born Siegfried Bettman, who established the Triumph Cycle Company in 1886 in Coventry, England, to make bicycles.

Ten years later, in 1896, Bettman started the Orial Company in his native Nuremberg, Germany, which eventually became Deutsche Triumph Fahrradwerke AG, or the German Triumph Cycle Company. Production of motorcycles started in England in 1902, and the following year in Germany, with engines and other components shipped from Coventry. Although English sales were strong, German sales floundered, and production of motorcycles in Germany ceased in 1907.

Motorcycle production resumed following World War I, with the successful 275cc 2-stroke "Knirps" (meaning imp or knave), a close copy of the pre-war English 225cc Baby Triumph. The two now independent companies continued their association until 1930, with German Triumphs frequently using English Triumph engines.

To overcome confusion created by the close association, after 1930 English Triumphs were sold in Germany as TEC models (Triumph Engineering Coventry) while the German bikes used the Orial name for export. That is, until the French firm of the same name objected. After 1931, TWN (Triumph Werke Nuremberg) was used. At this time, imports of English Triumph engines ended.

TWN moves on
During the Thirties, TWN produced an extensive range and was fourth in sales in Germany behind DKW, Zundapp and NSU. The range included small 2-strokes and the mighty "RR" model: a 741cc V-twin side-valve with a Swiss MAG engine.

Technical chief Otto Reitz developed TWN’s BD250 split-single 2-stroke, using two pistons, two cylinders and a shared combustion chamber fed through a rotary inlet valve. The split-single idea was to open the exhaust ports before the transfer ports, thus encouraging gas flow into the cylinder without losing fresh charge through the exhaust.