Spinors exhibit the well-known property that a full return to their original state requires a 720° rotation rather than 360°. While this behavior is conventionally attributed to the double-cover topology of the rotation group and treated as a representational feature, its geometric interpretation often remains implicit. This work re-examines spinorial rotational closure from a structural perspective, focusing on the limitations of three-dimensional rotation space in providing a globally continuous description of spin-1/2 states. The paper introduces a minimal rotational closure parameter W, interpreted as an explicit degree of freedom associated with the fiber structure of spinorial representations. The analysis does not propose new mathematical structures or physical dimensions; rather, it makes explicit a closure coordinate already implicit in the standard SU(2)/spin-bundle formalism. By isolating this parameter, the work clarifies the origin of the 720° periodicity as a projection effect arising from dimensional reduction, and positions the result as a foundational geometric framework for further investigations into dimensional structure and rotational consistency.