Abstract: A roller cutter assembly comprising a cutter hub adapted for rotation with respect to a rock face and having a peripheral surface with an axially extending width. The first cutter ring is located on the cutter hub. A second cutter ring is also located on the cutter hub. Both the first cutter ring and the second cutter ring are adjustable between at least first locations and second locations along the width of the peripheral surface of the cutter hub such that reorientation of at least one of the first cutter ring and the second cutter ring on the cutter hub alters the axial spacing between the first cutter ring and the second cutter ring, resulting in alteration of the spacing of the cutters located thereon.