By way of example, a cam assembly and strap based closure system using a spiral is configured for bringing two sides of an article together. When the user inserts the strap into the cam assembly and turns a knob, the strap is driven into the cam assembly and the strap pins engage one or more cam spirals. The system is configured such that strap pins are engaged at a constant angle which may be self-locking. The system is infinitely adjustable and the torque felt by the knob is constant. The system is configured to be a quick release system and allows rapid insertion of the strap for faster operation.