DkW URe 250 1937
After the happy but short career of the Garelli motorcycle in
the early 1920s, no other motorcycle manufacturer (except for Scott in England,
which raced only locally) tried to match a two-stroke engine against the most
famous British and Italian four-stroke engines.
The DkW company of Zschopau, however, had great faith in mixture-fed engines.
For years the company had been producing motorcycles with two-stroke engines in
various displacements. The DkW two-strokes, used mainly in minor races, stood up
well against their competitors' finely tuned four-stroke engines.
In 1928 a two-stroke, single-cylinder DkW 175 with supercharger won in its class
at the Italian Grand Prix. The motorcycle, ridden by Geiss, generated 11 h.p. at
5,000 r.p.m., putting it at least on a par with Tonino Benelli's unbeatable
Three years later Zoller, the DkW designer and racing manager, set out to prove
that the two-stroke engine was just as good as any other kind. In order to make
his idea a reality he followed two paths: He organized the most impressive
racing team that had been seen in Europe, and he built a brand-new engine that
was revolutionary in being a two-stroke two-cylinder with supercharging by means
of a cylinder pump.
The Zoller engine had two cylinders that were joined by a
single combustion chamber. There were two pistons with a single piston pin. The
main connecting rod was that of the rear cylinder; the other, smaller one was
linked to the main one and worked on the same coupling axis. The motorcycle was
fairly old-fashioned and heavy in appearance. The prototype had a rigid chassis
with front-wheel elastic suspension. After 1935 a rear-wheel guide suspension
—with vertical sliding pivot and spring and a hydraulic shock absorber—was
This was the URe. The German motorcycle raced with varying success between 1935
and 1937. The DkW racing unit, consisting of some 100 people, always arrived
early at the track to handle every detail of the race. Each racer had three
motorcycles at his disposal as well as a certain number of mechanics.
The DkW URe 250 also won many races run by private racers. After it had
confirmed Zoller's theories about the viability of the two-stroke engine, DkW
replaced the URe in 1938 with the new model ULd.
Motorcycle: DkW URe 250 Manufacturer: DkW, Zschopau Type:
Racing Year: 1937
Engine: DkW two-cylinder with two-stroke cycle and horizontal cylinder pump
supercharger, gill air intake. Displacement 123.5 + 124.9 = 248.4 cc. (47.5 mm.
X 69.7 mm. and 47.5 mm. X 70.5 mm.)
Transmission: Four-speed separate
Power: About 30 h.p. at 5,000 r.p.m.
Maximum speed: Over 105 m.p.h.
Chassis: Continuous double cradle in tubular elements. Front and rear, elastic
Brakes: Front and rear, central drum