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2311
ATK
406 / 604 - 1991
The wonder of Uncle Sam
"Made in USA" is the proud legend boldly emblazoned alongside the Stars and Stripes on the rear suspension of the ATK motocross and enduro bikes. National pride is justly evoked by this machine built in Los Angeles.
Patriotic Pride
Its publicity is calculated to raise national fervor. Advertisements inform motorcycle enthusiasts that the ATK is even capable of tackling the lunar surface. Ads feature the American flag planted on the moon by astronaut Neil Armstrong. These motorcycles rise above the craze for ever more high technology: air-cooling is good enough for them, there are no valves in the exhaust and the rear suspension is not progressive.
Brilliant Final Drive System
The ATK is all about simplicity, reliability, lightness, performance and economy. But most of all, it is American-built. Extremely well made, the ATK takes its name ("Austrian Torque Konverter") from the brilliant system of constant chain tensioning invented by Austrian engineer Horst Leitner. The system irons out all the drivetrain unevenness caused by acceleration and braking (the rear brake is mounted on the gearbox output shaft). Equipped with Rotax engines – 250 or 400cc two-stroke, 350 or 600cc four-strokes – the ATK is a lively performer. The 350 even boasts fuel injection. American magazines hail this handsome machine as "the eighth wonder" of the two-wheeler world!
SPECIFICATIONS
Engine: air-cooled Rotax single-cylinder 244/399cc two-stroke; 352/ 562cc four-stroke
Valves: (four-stroke) overhead-camshaft; four valves
Fuel System: rotary intake valve (244cc); carburetor (399cc/562cc); fuel injection (350cc)
Transmission: constant-tension chain final drive
Suspension: inverted telescopic forks, 11.8 inch displacement (front); swinging arm, 13 inch displacement (rear)
Brakes: disc (front); disc on gearbox output shaft (rear)
Wheels: wire (front & rear)
Weight: 205 lb (250); 213 lb (406); 254 lb (604)
This American cult bike uses the constant-tension chain drive invented by Horst Leitner.