A stent delivery system includes a wire collection device which is constructed with a thumbwheel coupled to a collection spindle that is rotatable to collect a retraction wire about the collection spindle. A proximal end of an outer stent-constraining sheath is coupled to the collection spindle by the retraction wire and a distal end of the outer sheath retractably surrounds a distally-disposed self-expanding stent. The wire collection device includes a first set of gears at a higher gear ratio and a second set of gears at a lower gear ratio. Stent deployment speed may be controlled or varied by switching or alternating between engaging the first of gears and the second set of gears, thereby accommodating changing resistance as the outer sheath is retracted and releases binding force of the stent.