Thanks. I see their next episode is on The Boring Company. The test sample of one got their attention with 21% improvement. They noted 4% over a few weeks, a more likely result. Two ways over the same route, is not the same route. They carried both sets of hupcaps but didn't quantify any change in altitude between A and B.
"Here" to this thread specifically? They mention the Tesla aero wheel but don't offer a DIY alternative. Ta-da:
Here is the cleanest open wheel I've seen, the Mariani Farms roadster:
The rim is wider that the tread so that the sidewall forms a continuous curve with the hubcap. Which laps the tire — you can see the 14(!) button-head cap screws at the rim and 8 more for an inspection plate for the bearings. Matched backing plates.
Note the external valve stem caps, the downfall of most full disks.
Note also genuine M
oon
spun aluminum disks are available with Dzeus fasteners. The stainless steel snap-on (and offs) will weigh twice as much.