An impact bed for use with belt conveyors comprises a base frame having parallel, spaced-apart side members extending lengthwise where the side members have an arcuate, concave upper edge. Attached to the upper edge of the side members is an arcuate, concave plate having plural rows, each of a plurality of apertures or alternatively a plurality of tubes or channels having apertures may be used. Completing the assembly are a plurality of polymeric bars, with a smooth upper surface and a plurality of lugs dimensioned and spaced to fit into the plurality of apertures of one of the plural rows. The apertures and lugs are designed to interlock with one another such that no special tools are needed to remove the bars form the top plate when the bars become worn out. Channels having flex points may be used to support the bars. Idlers may be used on the supports.