IntercityBike has been experimenting with a sun cap for the DF meant to shield the rider from the sun – not necessarily improve the aerodynamics. Several people have prototypes and have been reporting on them on BentriderOnline. Some people are claiming that the sun cap actually improves the aerodynamics. Here’s an example.

This sounded like a good idea to me. I had thought about making a mold of my race hood for a long time. I’d like to be able to experiment with different hood configurations. With the idea of the sun cap floating around, I decided to start the mold of my factory race hood.
I won’t go into it here, but let it be known that I deserved an F- on that mold. The hood has some tricky shapes and I misjudged the parting lines for making it a 2-piece mold. It took me many hours of hard work to extract my original race hood from my mold. Clearly, I would never be able to use this mold to make a full race hood. But after looking at it a while, I realized that I could at least make a sun cap using this mold. So I made one sun cap, body worked it and painted it. From that piece I made a dedicated, 1 piece sun cap mold.
Once I was able to make the part, I had to come up with a good mounting system. I got fancy designing all kinds of aerodynamic struts. None of my ideas panned out, so I resorted to copying a mounting solution posted by RobertM on BentriderOnline. This solution consisted of 2 round pieces of aluminum tubing with 3D printed plastic attachments. I used his idea of attaching 2 bungees at the rear of the hood to hold it all in place. Here’s my first example. I’ll be testing this soon to make sure that it doesn’t fly off or rattle too much.

I was able to position the struts so that my windscreen was still usable with the sun cap.

Thanks to RobertM for posting such good descriptions and photos on BentriderOnline of his sun cap.