Through analyzing the motion when motorcycle runs on the bump road, the 5-DOF multi-body dynamics model of motorcycle is developed, the degrees of freedom include vertical displacement of sprung mass, rotation of sprung mass, vertical displacement of driver, and vertical displacement of front and rear suspension under sprung mass. According to Lagrange Equation, the differential equations of motion and state-space formulation are derived. Then bump road is simulated by triangle bump, and input displacement is programmed by MATLAB. With the input of bump road, motorcycle ride comfort is simulated, and the simulation results are verified by experiment results combined with two channels tire-coupling road simulator. It indicates that the simulation results and experiment results match well; the 5-DOF model has guidance for development of motorcycle ride comfort.

The outsourcing production are performed not only by the supplier but also by buyer, so the intangibility and unverifiability of their contributed resources bring on double moral hazard. Focused on double moral hazard, an outsourcing contract of cooperative production of motor vehicle is designed with principal-agent theory. The maximization of benefit of the outsourcing will be given by the optimization between the fixed payment and the proportion of revenue-sharing under the limitation of the participation constraint and incentivecompatibility constraint. Subsequently, the influence of exogenous variable's on the optimized contract parameters is further analyzed. At last, the conclusions are proved by a numerical example.