In one aspect, a stent delivery system (100) includes a catheter (110) having two or more pullwire lumens (112a, 112b) evenly spaced about the central axis of the catheter and thereby balanced within the catheter. Pullwires (120a, 120b) are positioned in the pullwire lumens (112a, 112b). Proximal portions of the pullwires (120a, 120b) are attached to a connector (130), which is attached to a master pullwire (150). The connector (130) has a given range of motion that allows the pullwires (120a, 120b) to move within the pullwire lumens (112a, 112b), thereby ensuring full flexibility of the catheter (110) The pullwires (120a, 120b) assume different lengths.; A pullwire positioned over the outer curve of a flexed catheter may be longer than a pullwire positioned within the inner curve of the catheter, preventing the catheter from being straightened or displaced by the action of retracting the pullwires. The catheter may serve as either an inner member on which a stent is mounted or a sheath enclosing a stent.