Abstract: A bicycle frame with a counter-rotating four bar linkage system includes a front frame section, a rear frame section, and a shock absorber. The front frame section includes a top tube, a head tube, a seat tube, a bottom bracket, a down tube and a pivoting base formed on the down tube near the bottom bracket. The rear frame section is connected pivotally to the front frame section and has two seat stays, two chain stays, two dropouts, a connecting member, an upper linkage member, a lower linkage member and a parabolic virtual pivot (PVP). The PVP moves in a forwardly and upwardly parabolic trajectory and the dropouts of the rear frame section move in a nearly vertical trajectory when the rear frame section is pivoting.