High efficiency bicycle suspension

In a bicycle having a frame, handlebar-steering, seat front and rear ground engaging wheel assemblies attached to said frame of said bicycle, and a suspension unit, said suspension unit having a linkage, said linkage having at least one rotary shock absorber having an off-center cavity, working fluid filling said cavity and a rotary shaft and a vane element mounted on said rotary shaft, said off-center cavity having walls so that as said rotary shaft of said shock absorber is rotated, said vane element sweeps a path in said off-center cavity causing said working fluid to be displaced through at least one fluid control path selected from fluid metering gap, orifice or fluid logic device for resisting an applied rotary displacement and means mounting said suspension unit between said frame and at least one of said assemblies, said linkage having a plane normal to the axis of said rotary shaft and including said path of said vane, said linkage further comprising pivots and lever arms constructed so as to provide a high resistance to deflections out of a plane through the plane of said, and said linkage including one or more spring elements, said one or more springs having a spring rate which provides positive centering force to reposition the assembly to an equilibrium position from any other position.