Owing to the limitation of fossil fuels and high consumption and pollution for transportation, the vehicle industry is looking for other sources of energy. A fuel cell hybrid electric vehicle (FCHEV) could be a suitable solution considering the state of the art of main components. This paper presents the simulation of powertrains for FCHEVs in order to dimension the fuel cell (FC) as primary source of energy and to investigate the power flows during both motoring and recuperative braking. For this purpose a Matlab/Simulink (R) model has been built up which can be used for a wide range of applications. The results of simulation show which is the best powertrain configuration for two-wheeled vehicles in three different cases: a bike in which the traction force is provided by both electric motor and the pedaling of the cyclist, a bike in which the traction force is provided only by an electric motor without pedaling and a motorcycle for 2 passengers. Specifically, the consumption, the state of charge (SOC) of battery and the amount of energy generated by each source of energy have been monitored. The model validation was done by comparison between the obtained results and scientific articles in the literature.