Abstract: A suction transfer actuation system for a transfer drum of a multi-color sheet-fed rotary printing press for turning successive sheets, by rear-edge turning, during the sheet transfer from one printing unit to another to facilitate printing on the back side of the sheets. A plurality of suction arms are rigidly connected to a hollow suction rocker shaft connected to actuating levers carrying guide rollers engaging curved guide cam surfaces on a guide bar mounted on the transfer drum. The suction actuation system is driven by way of a cam rigidly mounted on the press frame engaged by a cam follower roller to oscillate a drive lever coupled by a link to a drive arm on the rocker shaft to rock the suction arms toward and away from the one printing unit under the guiding influence of the guide cam and guide rollers.