I don't think it's race legal, but you can put a piece of electrical tape on your valve stems to create a "tail" for improved aerodynamics. John Cobb suggested doing that method on exposed cables, too. I tried it once on my old TMO1 that had a lot of exposed cables and I believe it worked somewhat.
I've always wondered what that would look like on spokes. And I'm guessing they would bend and yield under high yaw conditions too, since tape is soft and flexible. Somebody should test that at a wind tunnel just to see.
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