According to "Bicycle Science" by David Gordon Wilson (MIT Press, 3rd edition, 2004), bladed spokes will be 8% more aero than non bladed spokes.

https://www.goodreads.com/book/show/...ycling_Science



8% refers to the spokes alone and does not mean that the bike as a whole will be 8% more aero or use 8% fewer watts.

That number is a generalization of bladed vs round. I don't know what specific brand and models were used to test.


-Tim-