Evaluation of the Ride Comfort of a Mountain Bike with a Rider in Standing Posture using a 6DoF Simulink Model

The ride comfort of a mountain bike (MTB) is considered as a viable factor since it must be ridden on an uneven terrain. The rider’s safety and comfort are always priority when designing the suspension system of an MTB. The existing 4DoF multibody model is not capable enough to measure all the responses exhibiting on the mountain bike with the rider in standing posture. For the first time, this study proposed a 6DoF model for suspension optimization which is capable enough to observe frequency responses and acceleration pulses on the body of the rider of a mountain bike while standing. The study designed a 6DoF Simulink model to measure all the possible active and reactive forces exerted by the road profile and the rider at the same time. This study evaluates the ride comfort between the 4 same bike models but with different suspension parameters. The results from the models showed that the resonant frequency of the bike rider varied from 3.1Hz to 5.08Hz and justify the statement that the less deflection of the chassis of the bike increase the resonant frequency of the rider. Moreover, it also decreases the phase margin and gains margin which affects the stability of the suspension system. The measured resonant frequency of the chassis varied from 11.9Hz to 12.7 which was inversely proportional to the resonant frequency of the rider. The proposed model was tested and validated from the literature and considered to be a valuable contribution to the field of vehicle dynamics.