The design of a bicycle depends on the desire of users. An excellent bicycle does not only include a nice structure, but also takes the size of every part on bodies of riders into consideration. Therefore, the most important purpose for designer is that the bicycle should fit in to the rider's posture and comfortable feeling on the bicycle. To establish this evaluation application program on computer simulation model with bicycle riding comfort enable the producer to have preferable references for bicycle design. The research using CAD systems looks for the standard parameters of bicycle construction to set up a computer-simulated riding model. After creating a data bank of riders' physiological and psychological responses, one can analyze the parameters of the comfortable riding model with computer simulation, including seat height and height of handlebars. In addition to EMG results, riding comfort was assessed based on the regression curve of the riders' subjective sensations with respect to the seat height. This computer simulation model can be utilized by manufacturers and designers for setting up a standard of bicycle size. The computer simulation model established by this system will improve the development of ergonomic analysis of bicycles and help design more comfortable bicycle for riding.