On the Beneficial Effects of Anti-Squat in Rear Suspension Design of a Drag Racing Motorcycle

Abstract

In the drag racing environment, maximizing tractive effort is essential to competitive performance. Anti-squat is a transient vehicle suspension parameter which can dramatically affect tractive effort available at the motorcycle drive tire. This paper addresses the design of a four-link rear suspension for a drag racing motorcycle to provide anti-squat, which increases rear tire traction, thereby improving vehicle acceleration performance. Utilizing PC based CAD, finite element analysis and dynamic system analysis software, a motorcycle rear suspension system was designed, built and tested under actual racing conditions. Parametric studies using dynamic theoretical models were conducted for both unsuspended and four-link equipped versions of the same vehicle. Based on the results, it is shown that the four-link suspension, when applied to a drag racing motorcycle, does provide opportunity for improving tractive effort at the beginning of a race which will improve overall drag racing performance.