This study used recumbent exercise bikes as the target of investigation and adopted a subjective assessment approach to evaluate the comfort of riding and cross-referenced the subjective assessment results with surface EMG measurements at different seat positions to determine the optimal riding seat position for users of different heights. A total of 48 healthy men with heights between 156 and 185 cm were recruited. Participants were required to ride the exercise bike at six different seat positions for three minutes at 65 revolutions per minute. A seven-point scale was used to conduct the overall comfort-level assessment. The results revealed that through crossreferencing with EMG measurement results, it was demonstrated that the riding comfort level subjectively perceived by the riders is quite reliable. The optimal seat position based on riding comfort levels for users of different heights were obtained by using a new fit method through linear regression analysis as follows: the horizontal distance between the seat center position and the center of the crankshaft (mm) is equal to 7.36  3.96  body height (cm), and the vertical distance between the seat center position and the center of the crankshaft (mm) is equal to 4.14  0.84  body height (cm).