A conveyor construction for a continuous belt conveyor. The conveyor includes a conveyor frame assembly constructed from a plurality of separate extruded and joined frame sections. The frame assembly can include a pair of side frame extrusions joined to a center frame extrusion by a pair of attachment rails. The conveyor construction further includes a series of spindle mounting assemblies that support a tensioning spindle on opposite ends of the conveyor frame. Each of the spindle mounting assemblies includes a gear rack and a pinion head that is rotatable to move the gear racks. The gear racks contact one of a pair of head plates that support the tensioning spindle relative to the frame.