Abstract: In a factory prefabricated drive system conversion unit for the handrail of an existing escalator, the drive system conversion unit includes a channel member adapted to be fixedly connected to an existing escalator structure, with a rotatable friction wheel being mounted between the channels and driven via a chain drive, having a plurality of pressing rollers, and a lever-operated tensioning device, with a set of cluster rollers, having a plurality of rollers, being mounted on a cluster roller base plate arranged on each side of the friction wheel, and also including a handrail turn around with a clamped roller chain having a plurality of both roller and chain links, as well as end pieces and intermediate guide members. Directionless cluster roller bases as well as directionless channels can also be utilized to simplify and speed up the conversion operation.