a sprocket assembly for a roller conveyor comprising a hub and a sprocket plate , the hub having a central cylindrical bore for fitting onto a round shaft of a roller , the hub having provisions for rotationally and axially locking it on a shaft in a manner adequate to transmit torque to the shaft and rotationally drive the roller , the sprocket plate having peripheral teeth adapted to be interengaged with a drive chain and a central bore capable of receiving the shaft , the sprocket plate and hub being constructed and arranged to be removably joined together with the centers of their respective bores coincident , said hub and sprocket plate having complementarily shaped radially extending abutting surfaces enabling the sprocket plate to develop torque on the hub by compressive forces developed by the radially extending sprocket plate surfaces against the radially extending hub surfaces .