The manufacture of a sole unit for footwear, such as an athletic shoe including an integral midsole/wedge or a separable wedge for use with a midsole. The integral midsole/wedge unit and the separable wedge comprise a shell and a core at least partially encapsulated within the shell. In the manufacture the core is supported in a mold by a plurality of pins extending from an upper and lower mold half toward a parting line; or the core is supported on one or the other of an outsole or insole of the sole unit and closed in the mold. The material of the shell is poured or injected into the mold.