Null Winds Technology has taken their Upper Wheel Fairings to Kickstarter to bring wind cheating shields to the masses.
Admittedly, they’re not for racers. And they’re different looking. But the science is interesting, so let’s have a look. Inventor Garth Magee says wind speed affecting the top of the wheel is up to 3x the speed of the headwind. That’s because the tire and spokes are all rolling directly into the wind at twice the speed of the bicycle. Of course it’s variable based on head wind speed and bicycle speed, but the power needed to overcome the drag rises in proportion to the cube of the wind speed. So, the faster the wind and the faster you try to go, the more power you’ll have to pump out for smaller and smaller gains.
His Upper Wheel Fairings block the spokes from “fanning” the wind against your efforts. Magee says the result is up to 20% more speed for a given effort…
Using his background as an engineer and aerodynamic hacks for his hobby as a paraglider, Magee say the effects of thin wires (ie. spokes, here) in reducing speed. He modified his own glider with thinner filaments to reduce drag. On a bicycle, there’s a limit to how thin spokes can get, so he looked for another solution. And here we are.
The fairings themselves clamp to the frame or fork and use adjustable mounts to position them as close to the rim as possible. Stiffening structures on the inside prevent them from flexing into the wheel or rim, and small nylon bumpers provide a smooth gliding surface should the rim flex into the fairing during cornering, etc.
We don’t see these taking off with the racer crowd thanks to the added weight. And since they wouldn’t be allowed in the peloton anyway. But for touring bikes, the front in particular could very easily mean better days on the bike while rear pannier bags helped shield the back wheel.
Interested? Help them fly over on Kickstarter.