Patent ID: 8033558

Claim:
A bicycle frame comprising: a front part; and a rear suspension system including: a connection member connected pivotally to said front part; a rear part including two seat stays having front ends connected pivotally to said connection member at a location spaced from said pivotal connection to said front part to define a first moment arm of said connection member, and two chain stays having front ends; a cylinder having an upper end and a lower end, said upper end being pivotally connected to said connection member at a location spaced from said pivotal connection to said front part and spaced from said pivotal connection to said front parts of said two seat stays to define a second moment arm of said connection member; and an axle extending through said front part at a location spaced from said pivotal connection to said connection member, said front ends of said chain stays, and said lower end of said cylinder for pivotally connecting said front ends of said chain stays and said lower end of said cylinder to said front part; wherein an upward displacement of said rear part about said axle relative to said front part pivots said first moment arm upwardly and thereby pivots said second moment arm upwardly to apply an upward force on said upper end of said cylinder.