A motorcycle comprising: a frame which supports a motor; a rear wheel operatively connected to said frame by means of a suspension configuring, with said frame, a quadrilateral kinematic mechanism, wherein said quadrilateral kinematic mechanism comprises: a swingarm which extends between a first connection axis, at said frame and/or said motor, and a third connection axis at said rear wheel; a reaction rod hinged to said frame by means of a second connection axis; a connecting rod which supports a wheel axis, wherein said connecting rod is rotatably connected to said third connection axis of said swingarm and to said reaction rod by means of a fourth connection axis, wherein a center of instantaneous rotation of said connecting rod is defined by the intersection of a first geometrical line passing through said first connection axis and said third connection axis, and by a second geometrical line representing the extension of said reaction rod, adjustment means (70, 80, 180) adapted to adjust the position of at least one of said connection axes (31, 32, 33, 34) of said quadrilateral kinematic mechanism with respect to the other connection axes (31, 32, 33, 34), in feedback to a compression variation of said suspension, such that said adjustment of related position of said connection axes varies the position of said center of instantaneous rotation so as to therefore vary the balance of said motorcycle, characterized in that said adjustment means comprise an actuator (76, 86) connected to a control unit of said motorcycle, said control unit being configured to receive an input signal of the variation of the compression of said suspension, and said actuator (76, 86) being configured to adjust the related position of at least one of said connection axes (31, 32, 33, 34) to modify said center of instantaneous rotation. a frame which supports a motor; a rear wheel operatively connected to said frame by means of a suspension configuring, with said frame, a quadrilateral kinematic mechanism, wherein said quadrilateral kinematic mechanism comprises: a swingarm which extends between a first connection axis, at said frame and/or said motor, and a third connection axis at said rear wheel; a reaction rod hinged to said frame by means of a second connection axis; a connecting rod which supports a wheel axis, wherein said connecting rod is rotatably connected to said third connection axis of said swingarm and to said reaction rod by means of a fourth connection axis, wherein a center of instantaneous rotation of said connecting rod is defined by the intersection of a first geometrical line passing through said first connection axis and said third connection axis, and by a second geometrical line representing the extension of said reaction rod, adjustment means (70, 80, 180) adapted to adjust the position of at least one of said connection axes (31, 32, 33, 34) of said quadrilateral kinematic mechanism with respect to the other connection axes (31, 32, 33, 34), in feedback to a compression variation of said suspension, such that said adjustment of related position of said connection axes varies the position of said center of instantaneous rotation so as to therefore vary the balance of said motorcycle, characterized in that said adjustment means comprise an actuator (76, 86) connected to a control unit of said motorcycle, said control unit being configured to receive an input signal of the variation of the compression of said suspension, and said actuator (76, 86) being configured to adjust the related position of at least one of said connection axes (31, 32, 33, 34) to modify said center of instantaneous rotation. a swingarm which extends between a first connection axis, at said frame and/or said motor, and a third connection axis at said rear wheel; a reaction rod hinged to said frame by means of a second connection axis; a connecting rod which supports a wheel axis, wherein said connecting rod is rotatably connected to said third connection axis of said swingarm and to said reaction rod by means of a fourth connection axis, wherein a center of instantaneous rotation of said connecting rod is defined by the intersection of a first geometrical line passing through said first connection axis and said third connection axis, and by a second geometrical line representing the extension of said reaction rod, adjustment means (70, 80, 180) adapted to adjust the position of at least one of said connection axes (31, 32, 33, 34) of said quadrilateral kinematic mechanism with respect to the other connection axes (31, 32, 33, 34), in feedback to a compression variation of said suspension, such that said adjustment of related position of said connection axes varies the position of said center of instantaneous rotation so as to therefore vary the balance of said motorcycle, characterized in that said adjustment means comprise an actuator (76, 86) connected to a control unit of said motorcycle, said control unit being configured to receive an input signal of the variation of the compression of said suspension, and said actuator (76, 86) being configured to adjust the related position of at least one of said connection axes (31, 32, 33, 34) to modify said center of instantaneous rotation.