The brothers Falk and Horst Hartmann were sidecar racers in the 1960s, and opened a business named F. u. H. Hartmann which became Horst Hartmann Gespanntechnik (HGT) in 1989 after Falk left the partnership.
The HGT Airline was first produced in 1985. The Dreamline model appeared in 1988, equipped with Koni suspension and a Brembo disc brake, and could be supplied with an auxilliary fuel tank. The HGT Dreamline K1 had a 100 h.p. BMW K1 engine. The Tourline model was also available.
Michael Unger, who worked with HGT, discusses K1100 Dreamline and K1 Airline projects at hgt-gespanne.de.