Softride and Zipp
The Softride Suspension System was launched at the Interbike 1989 bike show. The original SRS systems consisted of two foam filled fiberglass boxes bonded together with a viscoelastic layer. Originally intended for the use in mountain bikes, Softride produced its first full-fledged mountain bike, the PowerCurve, in 1991. During 1996 Softride released its first aluminum frame road bike, the Classic TT. The Softride Suspension System is used almost exclusively for triathlon racing. Softride ceased bicycle production in 2007 after the design was banned from racing.
A very closely related suspension design to the Softride is the Zipp 2001, a contemporary competing beam bicycle, where the suspension was in the hinge, rather than in flex of the beam itself.
Read more about this topic: Bicycle Suspension