1980: BMW R80GS introduced – 50bhp, 167kg, air-cooled, Boxer twin. The absolute daddy of the giant trailie genre.
1987: BMW R100GS released – now making 60bhp, weight is up to 187kg thanks to stronger frame, new forks and bigger, better brakes. Discontinued 1993.
1994: BMW R1100GS launched, discontinued 1999 (replaced first by R1150GS and then the R1200GS).
BMW R1100GS ABS: Otherwise identical barring Advanced Braking System.