A spiral conveyor system comprising: a drum associated with a motor, wherein the drum extends from a drum bottom to a drum top; a conveyor belt traveling helically about the drum from an entrance end to an exit end; a drive element for engaging with the conveyor belt; wherein the drive element comprises a rib associated with the drum, and configured to fit between protrusions of the conveyor belt; wherein the rib extends from the drum entrance end to an exit end; at least one drive face positioned on the rib; at least one contoured surface on the rib wherein the contoured surface defines a height of the rib, and wherein the height of the rib above of the surface of the drum varies along a length of the rib; wherein the protrusions of the conveyor belt include at least one belt surface configured to engage the at least one drive face ; characterized in that : the conveyor belt includes at least one belt surface configured to engage the at least one contoured surface of the rib proximate the entrance end of the drum, wherein the conveyor belt proximate the entrance end of the drum has a first radius defined by the height of the rib ; wherein the belt is held at the first radius by engagement of the circumferential support surfaces of the belt with the circumferential support surfaces of the drive element ; and due to the direction of travel, the relative position of protrusion and drive element is such that the drive element is trapped behind the protrusion so that the drive element can push against the protrusion. a drum associated with a motor, wherein the drum extends from a drum bottom to a drum top; a conveyor belt traveling helically about the drum from an entrance end to an exit end; a drive element for engaging with the conveyor belt; wherein the drive element comprises a rib associated with the drum, and configured to fit between protrusions of the conveyor belt; wherein the rib extends from the drum entrance end to an exit end; at least one drive face positioned on the rib; at least one contoured surface on the rib wherein the contoured surface defines a height of the rib, and wherein the height of the rib above of the surface of the drum varies along a length of the rib; wherein the protrusions of the conveyor belt include at least one belt surface configured to engage the at least one drive face ; characterized in that : the conveyor belt includes at least one belt surface configured to engage the at least one contoured surface of the rib proximate the entrance end of the drum, wherein the conveyor belt proximate the entrance end of the drum has a first radius defined by the height of the rib ; wherein the belt is held at the first radius by engagement of the circumferential support surfaces of the belt with the circumferential support surfaces of the drive element ; and due to the direction of travel, the relative position of protrusion and drive element is such that the drive element is trapped behind the protrusion so that the drive element can push against the protrusion. the conveyor belt includes at least one belt surface configured to engage the at least one contoured surface of the rib proximate the entrance end of the drum, wherein the conveyor belt proximate the entrance end of the drum has a first radius defined by the height of the rib ; wherein the belt is held at the first radius by engagement of the circumferential support surfaces of the belt with the circumferential support surfaces of the drive element ; and due to the direction of travel, the relative position of protrusion and drive element is such that the drive element is trapped behind the protrusion so that the drive element can push against the protrusion. <EOS>