In this paper a validation of the Luenberger-like nonlinear observer, proposed in one of our recent work, is performed by means of a commercial motorcycle simulator. The previous paper has introduced the design of a nonlinear Luenberger observer to simultaneously estimate both the motorcycle lateral dynamics and the rider action. The vehicle lateral motion is described with a two-body linear model which takes into account the longitudinal speed variation as a time-varying parameter. Then, the Takagi-Sugeno approach combined to the Lyapunov theory, linear matrix inequalities tools and L 2-gain property are used to demonstrate the observer's convergence through an input-to-error stability. Finally, the effectiveness and the robustness of the observer are tested on three different realistic riding scenarios by means of the well-know multibody simulator BikeSim. Finally, the estimation performances are compared to previous works.