Abstract: A decoiler for delivery of wire or rod feed stock to a downstream production machine from a pre-formed coil. The decoiler includes an extended length rotatable mandrel adapted to extend along the interior of the coil such that the mandrel supports loops of the coil in hanging and slidable relation along the mandrel. At least a first feed head is disposed adjacent to the proximal end of the mandrel. The first feed head is adapted to feed the wire or rod feed stock from a rear loop of the coil outwardly in a curved path to form a spiral feed loop having a diameter greater than the coil. A variable height guide element is disposed at a position below the first feed head. The variable height guide element engages and follows an interior of the spiral feed loop to change height with a change in diameter of the spiral feed loop and to provide an output signal for speed control of the first feed head to maintain the diameter of the spiral feed loop within predefined limits.