ATK was founded by Austrian-born engineer Horst Leitner in the 1980s. The name "ATK" comes from Leitner's 1981 patented device to eliminate chain torque for improved handling. Known later as the A-Trax, Leitner originally called the device the Anti-Tension Kettenantrieb (German: chain drive).
As of 5/20/2011 ATK has associated itself with S&T Motors, parent company of the Changwon, South Korea based Hyosung. S&T/Hyosung will make motorcycles with ATK nameplates and a few requested changes to the standard Hyosung Motorcycles. Both supersport and cruiser models from 250 to 700cc engine sizes. All have V-Twin engines.
Beginning in early 2009 ATK offered a 700 cc two stroke Motocross bike available in limited quantities.
The Initimidator is a monster dirt-bike powered by a 78 hp (58 kW) Maicotwo-stroke engine. As of June 2008, only Maico itself has a machine comparable to this. ATK also has a line of atvs that use a 900cc efi engine.