STREAMLINED TAPERED BICYCLE WHEEL SPOKE

摘要

A longitudinally tapered wheel spoke having a thin aerodynamic cross-sectional profile proximate to the wheel rim and tapering to a round profile toward the central hub, with the tapered section optimized for reduced drag in both headwinds and crosswinds when the spoke is positioned directly above the axle.

主权项

1. An apparatus for reducing vehicle propulsory counterforces countervailing drag-induced resistive forces upon a terrestrial vehicle employing a wheel assembly exposed to headwinds and crosswinds impinging thereon above the level of an axle when the vehicle is in forward motion, comprising:
a structural spoke fastening an outer rim to a central hub of a wheel assembly exposed to headwinds impinging thereon above the level of an axle of said wheel assembly while employed on the vehicle in forward motion; a longitudinal section of said spoke tapering lengthwise along the longitudinal section; said tapered spoke disposed in streamlined orientation to reduced drag from a headwind combined with a crosswind impinging on the longitudinal section when the longitudinal section is positioned directly above the axle in a most elevated position within an upper region of said wheel assembly comprising a major upper drag-inducing surface located wholly above the level of the axle and comprising the primary vehicle-drag-inducing wheel surface on said wheel assembly, with said region being centered extending both above and below centered around the level of a critical elevation which is centered around the primary vehicle-drag-inducing wheel surface of said wheel assembly; the critical elevation positioned not lower than a level equal to 75 percent of the outer diameter of said wheel assembly; said tapered spoke comprising a plurality of different cross-sectional profiles spaced lengthwise along the longitudinal section with said cross-sectional profiles varying unidirectionally in shape along the longitudinal section from one to the next adjoining said cross-sectional profile, progressing steadily along the longitudinal section from a thin aerodynamic cross-sectional profile located proximate to an end of said tapered spoke attached to the rim of said wheel assembly to a first circular cross-sectional profile located toward an opposite end of said tapered spoke for attachment to the central hub while also comprising a progressively changing series of oval cross-sectional profiles located near the midway position along the longitudinal section between said rim end and the first progressive position toward said opposite end having said first circular cross-sectional profile located toward said opposite end; said tapered spoke comprising a major axis of each said cross-sectional profile along the longitudinal section aligned in the same streamlined orientation within said wheel assembly for reduced drag from headwinds; said tapered spoke in the most elevated position having the longitudinal section extending from proximate to said tapered spoke end attached to the rim toward said opposite end attached to the central hub across said upper region a sufficient distance to thereby extend the longitudinal section below the level of the critical elevation; and said tapered spoke in the most elevated position providing reduced drag on the longitudinal section within said upper region from the combined wind impinging thereon wherein the vehicle propulsory counterforce countervailing an upper wheel drag force from the combined wind impinging on the longitudinal section is reduced when the vehicle is operated nominally under a range of external headwind and crosswind conditions.