A motorcycle comprising: a frame supporting 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 wheel axis at said rear wheel; a chain drive to transfer a motor torque generated by said motor to said rear wheel, said chain drive extends between a pinion hinged to said motor by means of a second connection axis and a ring connected to said wheel axis, wherein said chain drive defines an upper taught branch which connects said pinion and said ring, wherein said ring defines a connecting rod element which connects said wheel axis to said upper taught branch of the chain drive, wherein the center of instantaneous rotation of said connecting rod element is defined by the intersection of a first geometrical line passing through said first connection axis and said wheel axis, and by a second geometrical line representing the extension of said upper taught branch of said chain drive; adjustment means (5, 5A, 180) adapted to adjust the related position of at least one of said connection axes (31, 32) with respect to the other of said connection axes (31, 32), in feedback to a compression variation of said suspension, such that said adjustment of related position of said connection axes (31, 32) 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 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, said actuator being configured to adjust the related position of at least one of said connection axes to modify said center of instantaneous rotation. a frame supporting 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 wheel axis at said rear wheel; a chain drive to transfer a motor torque generated by said motor to said rear wheel, said chain drive extends between a pinion hinged to said motor by means of a second connection axis and a ring connected to said wheel axis, wherein said chain drive defines an upper taught branch which connects said pinion and said ring, wherein said ring defines a connecting rod element which connects said wheel axis to said upper taught branch of the chain drive, wherein the center of instantaneous rotation of said connecting rod element is defined by the intersection of a first geometrical line passing through said first connection axis and said wheel axis, and by a second geometrical line representing the extension of said upper taught branch of said chain drive; adjustment means (5, 5A, 180) adapted to adjust the related position of at least one of said connection axes (31, 32) with respect to the other of said connection axes (31, 32), in feedback to a compression variation of said suspension, such that said adjustment of related position of said connection axes (31, 32) 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 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, said actuator being configured to adjust the related position of at least one of said connection axes 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 wheel axis at said rear wheel; a chain drive to transfer a motor torque generated by said motor to said rear wheel, said chain drive extends between a pinion hinged to said motor by means of a second connection axis and a ring connected to said wheel axis, wherein said chain drive defines an upper taught branch which connects said pinion and said ring, wherein said ring defines a connecting rod element which connects said wheel axis to said upper taught branch of the chain drive, wherein the center of instantaneous rotation of said connecting rod element is defined by the intersection of a first geometrical line passing through said first connection axis and said wheel axis, and by a second geometrical line representing the extension of said upper taught branch of said chain drive; adjustment means (5, 5A, 180) adapted to adjust the related position of at least one of said connection axes (31, 32) with respect to the other of said connection axes (31, 32), in feedback to a compression variation of said suspension, such that said adjustment of related position of said connection axes (31, 32) 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 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, said actuator being configured to adjust the related position of at least one of said connection axes to modify said center of instantaneous rotation.