Abstract: A guide mechanism for a passenger conveyor which includes a series of passenger platforms supported on and movable along a frame which has a support track for support rollers mounted on the platforms. The guide mechanism includes a monotrack guide rail, and a pair of horizontal pinch rollers supported by each passenger platform. The pinch rollers are in engagement with opposite sides of the monotrack guide rail. One of the pinch rollers is of a lower compression stiffness than the other pinch roller. The guide mechanism is coupled to a walking beam assembly wherein a pair of support rollers are mounted at opposite ends of a beam extending in the direction of movement of the conveyor, and the guide rail mechanism is coupled to the beam between the pair of support rollers.