In recent years the Whipple Carvallo Bicycle Model (WCBM) has been extended to analyze high speed stability of bicycles. Various researchers have developed models taking into account the effects of front frame compliance and tire properties, nonetheless, a systematic analysis has not been yet carried out. This paper aims at analyzing parametrically the influence of front frame compliance and tire properties on the open loop stability of bicycles. Some indexes based on the eigenvalues of the dynamic system are defined to evaluate quantitatively bicycle stability. The parametric analysis is carried out with a factorial design approach to determine the most influential parameters. A commuting and a racing bicycle are considered and numerical results show different effects of the various parameters on each bicycle. In the commuting bicycle, the tire properties have greater influence than front frame compliance, and the weave mode has the main effect on stability. Conversely, in the racing bicycle, the front frame compliance parameters have greater influence than tire properties, and the wobble mode has the main effect on stability.