On driving comfort, as well as on the driving safety, affects the driving way of motorcycle,itself. The road bumps and the behavior, i.e. the action of the drivers are the excitation i.e. the input function in the models that represent the dynamic response of the bike. In this paper motorcycle\'s stability investigation approach, during the real driving conditions, is presented. An appropriate physical-mathematical model of the motorcycle have been formed as the base for development of simulation modes, as well as designing and experiments conducting. The obtained results as correlative dependencies of the motorcycle\'s excitation and related motion modes are presented and discussed.