A ratcheting strap-down system for use with a crossbar to securely transport any variety of objects. A third gearset, driveably connected to the carrier of the second gearset and the ring gear of the first gearset, alternately drives the output at a predetermined lower speed relative to a speed of the carrier of the second gearset, and driving the output at substantially the speed of the ring gear of the first gearset. This mechanism further comprises a manually-operable lever system for moving the movable element between its first and second stable position.