A quasi-static model has been developed for a silent (inverted-tooth) chain drive featuring a rocker-pin-jointed chain and sprockets with involute teeth. The model incorporates the effects of clearances in the rocker-pin joints and the geometry of link/sprocket engagement. The influence of various model parameters on the chain drive torque-ratio is examined, a primary point of interest being the fluctuations in the torque-ratio due to chordal action. In some cases, the torque-ratio variation is found to be less than that for the equivalent pin-jointed chain drives. Additionally, the center distances corresponding to the maximum and minimum torque variation are not fixed, as in the case of a pin-jointed chain. An optimization method is used as an aid in determining the governing geometric constraints since multiple joint configurations can be selected, given the clearances introduced by the rocker-pin joints. The resulting system of equations is fully constrained for a physically consistent chain configuration.