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This work is basically a dirigibility study applied to tricycles of human traction, HPT - Human Powered Tricycle. The behavior of the vehicle is simulated in a track with compacted floor, contend curves, straight line, up and down grades. A simplified mathematical model is used to model the system (vehicle + cyclist). As the system of equations obtained is extremely coupled and non-linear, it is necessary to use numeric procedures to solve the equations and to obtain the behavior of the system during its path in the racetrack. The influences of the track and the mass center position of the vehicle in its stability, the behavior of the vehicle using chainset transmissions and CVTs (Continuously Variable Transmission) are also analyzed.

Through numerical simulations of a cyclist+bicycle system, a performance comparison was carried out between a traction drive continuously variable transmission (TD-CVT) and a traditional transmission (step-variable transmission) for bicycles. The objective was verifying the performance of both of them when the cycling frequency was kept invariable. For that, the principles of a TD-CVT were initially described. After that, the human characteristics of producing power in different intervals of time were considered. Then, the cycling frequencies which are most commonly used in biomechanical tests related to cycling were analyzed. Finally, the cyclist-bicycle system was modeled through Lagrance's movement equations. During the simulations, the cycling frequency values and the description of the transmissions used in a certain course were stored in order to be compared.