Spoke Fins cut bicycle spoke drag by more than 50%, even in crosswinds. Streamlined Spoke Fins swivel like a wind vane in response to variable crosswinds, which constantly change orientation as the wheel rotates. Cut Spoke Drag more than 50%. Effective in both Headwinds and Crosswinds. Reduce Pedaling Effort in All Winds. Enhance Stability in Crosswinds. Colorful Fashion Accessory for the Kids’ Bicycle. Optimally streamlined Spoke Fins reduce the spoke drag coefficient by more than 50% in the critical, faster-moving, drag-inducing region located nearest the wheel rim. Since round spokes have relatively high drag coefficients – thereby becoming the major contributor to overall wheel drag – reducing critical spoke drag also reduces total wheel drag. Spoke Fins are also tapered lengthwise to reduce drag principally on the critical uppermost spokes, where wheel drag most retards vehicle propulsion. Spoke Fins swivel to reduce pedaling effort under any wind condition, becoming especially effective on typical recreational bicycles with higher spoke-counts.