Originally Posted by
Koogar
I can't make out the fork ends too well, but I can't see how that would work. I'm no aerodynamicist, but I am a (sadly noncurrent) pilot, so I have had an interest in the subject. I've always conceptualized the primary function of winglets as reducing induced drag by smoothing the interaction of the high and low pressure regions at the end of the airfoil, a bit like an aerodynamic fence. Even if you treat the fork blades as airfoils that both have an angle of attack that is producing lift (i.e., differential pressure) they'd need lateral protrusions. That seems like something that would give the UCI fits. They could just be fairings or extensions meant to smooth airflow around the wheelnut / axle area. I guess you can always make an argument for incremental gains....
The bold is correct. The current design of winglets is what works optimally for planes at the speeds they travel. You can achieve a similar (albeit much smaller and not as effective) effect by sweeping the wingtips back, as well as increasing the wetted area of the wingtips. This only works at lower airpeeds, so may have bicycle applications where it works. It essentially tries to disrupt vortex formation, (by allowing the low and high pressure streams to meet along the trailing edge before spilling over the wingtip) instead of channeling and reducing the size of vortices as with the perpendicular design.
My guess is infinitely marginal performance gains, yet measurable marketing gains $$$$$.