The Influence of Static Factors on Seating Comfort of Motorcycles: An Initial Investigation

Objective: The aim of the current study is to examine the influence of static factors on overall seating comfort in motorcycles and validate the use of static lab-based setups for evaluating seating comfort in motorcycles. Background: Seating comfort in automobiles has two factors, static and dynamic. Research on seating comfort of passenger cars has shown that when the magnitude of vibration reaching the seat is low, comfort is largely determined by static factors. Studies have also validated the use of static lab-based setups for research on seating comfort in passenger cars. Static lab-based setups are easy to develop, provide a controlled environment, and efficient for experimental research. The riding posture, mass distribution, and dynamics of a motorcycle differ from a passenger car and warrant further investigation to extend the results from the research on passenger cars. Method: The study compares subjective rating of seating comfort and objective measurement of seat interface pressure in two test conditions: a static lab-based setup and actual driving on a flat test track where the magnitude of vibration reaching the seat is low. The vibration at the seat is measured for the driving trial. A group of 18 male volunteers from TVS Motor Company participated in the study, and two motorcycles from the economy/executive segment of India are used in the study. The subjective ratings are analyzed statistically using analysis of variance (ANOVA) and Pearson’s correlation. The vibration data are analyzed as per ISO 2631-1 to calculate the frequency-weighted acceleration, aw. Results: The results show that there is no significant difference between the two test conditions either in the objective measurements or in the subjective rating of comfort. There is also a statistically significant correlation between the subjective ratings of seating comfort in static lab-based setup and actual riding (r = .77, p < .01, n = 36). The mean aw at the seat while driving in the test track used in this study is 0.2 m/s2. Conclusion: Static factors have a significant influence on seating comfort in motorcycles. When the vibration reaching the seat is low (aw ≤ 0.2 m/s2), seating comfort is largely determined by the static factors. The use of static lab-based setups for evaluating static factors of seating comfort in motorcycles is validated. Application: The results of this study enable further research to understand the human criterion for seating comfort in motorcycles