US company Null Winds Technology is seeking Kickstarter funding for its swivelling Spoke Fins: nylon plastic fairings that are designed to cut spoke drag in both headwinds and crosswinds.
Fairings for your spokes? Uh-huh!
“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,” says Null Winds Technology. “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.
That’s not all.
“As the wheel rotates, Spoke Fins automatically adjust their streamlined alignment for the changing orientation of the effective wind vector impinging on the spoke. Spoke Fins swivel to reduce pedalling effort under any wind condition, becoming especially effective on typical recreational bicycles with higher spoke-counts.”
So, that’s it in a nutshell. There are enough wheels about with bladed spokes; why not just go for a set of those?
“Bicycle racers know that bladed aero-spokes quickly become ineffective in crosswinds,” says Null Winds Technology. “Spoke drag quickly increases when impinging winds are directed crosswise across the flat blades. In a direct headwind, the common round spoke develops more wind drag than does a bladed spoke. However, against a crosswind the bladed spoke can actually produce much more drag than a round spoke.”
Null Winds Technology doesn’t present any wind tunnel data relating to Spoke Fin-equipped wheels. To be fair, that’s understandable because wind tunnel time is very expensive.
The Spoke Fins do, though, seem to fall foul of the UCI’s technical regulations. Article 1.3.011 says, “Any device, added or blended into the structure, that [is] destined to decrease resistance to air penetration or artificially to accelerate propulsion, such as a protective screen, fuselage form of fairing or the like, shall be prohibited.”
Null Winds Technology are seeking US$30,450 (£19,908) to buy the eight-cavity polished steel injection mould it needs to produce Spoke Fins.
Assuming the target is met, a set of Spoke Fins will cost you from US$20 through Kickstarter, although they’ll ship to the US only via this campaign.
Mat has been in cycling media since 1996, on titles including BikeRadar, Total Bike, Total Mountain Bike, What Mountain Bike and Mountain Biking UK, and he has been editor of 220 Triathlon and Cycling Plus. Mat has been road.cc technical editor for over a decade, testing bikes, fettling the latest kit, and trying out the most up-to-the-minute clothing. We send him off around the world to get all the news from launches and shows too. He has won his category in Ironman UK 70.3 and finished on the podium in both marathons he has run. Mat is a Cambridge graduate who did a post-grad in magazine journalism, and he is a winner of the Cycling Media Award for Specialist Online Writer. Now over 50, he's riding road and gravel bikes most days for fun and fitness rather than training for competitions.