Photo ou archives : F-M. Dumas
820
ADLER
M 250 RS – 1955
Fabulous twins!
In 1949, Adler was one of the first German marques to recommence production after the war. Right up to the end of manufacture in 1957, it remained unapproachable as a maker of two-strokes. Late in 1952, Adler unveiled the MB 250, a two-stroke twin which quickly became known as the "Cannonball." It was equally successful as a touring bike, a sports bike or an off-roader. But it was particularly successful under another name, for the first Yamaha twin (the YD 1 of 1957) was more or less a direct copy of the Adler MB, and the subsequent Yamaha twins have followed its pattern.
A Fabulous Two-Stroke Twin
Soon the touring MB 250 was joined by the sporting 250 S, then by a racing version, the 250 RS with twin carburetors and swinging fork rear suspension instead of plungers. The 250 RS of 1954, still air-cooled, developed 26 hp @ 7500 rpm, weighed 216 lb and was capable of more than 105 mph. Highly prized in its native Germany, the Adler RS enjoyed a rare foreign success in France's Bol d'Or in 1954, where a solo RS and another with a side-car won their respective under-350cc categories.
Adler Takes to Water
Beginning in 1954, tuner/rider Hellmut Hallmeier perfected a water-cooled 250 RS, whose highly successful racing career continued into the Sixties. The last "works" RS Adlers ridden by Walter Vogel and Hellmut Hallmeier developed 39 hp at over 10,000 rpm, with a top speed of 125 mph.
SPECIFICATIONS
Engine: Transverse 247cc (54x54 mm) water-cooled twin inclined at 150 degrees
Power Rating: 30 hp @ 8500 rpm
Valves: two-stroke
Fuel System: 2 carburetors
Transmission: 4-speed
Suspension: leading link (front); swinging fork (rear)
Brakes: 7in drums (front & rear)
Wheels: 18in
Weight: 220 lb
Maximum Speed: 125 mph
This Adler RS 250 is a 1954 model fitted with a 1955 Hallmeier transformation kit -water-cooling, high-compression pistons, etc.