The effects of interconnected front and rear suspension systems on the in-plane dynamics of sportmotorcycle is investigated. The interconnected suspension mathematical description is presentedand included in a high-fidelity motorcycle model. The suspension behaviour under road step bumpinputs is studied for different values of stiffness and damping interconnection coefficients. Optimalvalues of interconnection coefficients are proposed for the current motorcycle model. Finally, theoscillating dynamics of the motorcycle at straight running conditions is studied through its normalmodes.