I thought that flat bladed spokes were for marketing. They actually aren't all that aero, especially with any side winds.

I've heard that the cx-ray type of ovalized spokes are more aero than the wider flat ones. And they look way nicer to me than the wider flat spokes.

If you build your own wheels, flat or ovalized spokes make it easy for an amateur builder to avoid windup. Expensive, though.

Googling for "bladed spokes drag aero", I found this wind tunnel test of 20 round vs cx-ray spokes. The cx-ray are 0.5 watt less at 25 mph.




And an old BF thread comment about wind yaw angles.