A characteristic relating to transmission of a longitudinal force input to a front wheel from the front wheel to a vehicle body is set to a first transmission force characteristic. A sensitivity of the vehicle to the longitudinal force transmitted from the front wheel to the vehicle body is set to first sensitivity. The maximum value of the square of a product of a value representing the first transmission force characteristic and a value representing the first sensitivity in a predetermined frequency range preset so as to include a frequency at which the value representing the first transmission force characteristic takes a peak value is set to an evaluation indication value. A complex spring constant in the vehicle longitudinal direction of the rear wheel suspension is set so that the evaluation indication value takes the minimum value out of values in a variable range of the evaluation indication value.