The steps of the escalator move along a curved path which has a fixed constant radius when viewed in plan. The step chain also follows the constant radius path and thus its effective length must vary at different locations along its path of travel in order to keep the step rollers on their constant radius tracks. The effective length of the step chain is varied using an eccentric pivot cam at chain link connections spaced along the chain whereby the degree of overlap of adjacent links can be changed by controlling the path along which cam actuating rollers travel. The cam actuating rollers control operation of the eccentric pivot cam link connections.