how does it work?

[featherliteCT1]

Aguyfromohio,

Thank you for the very informative post.

[Aguyfromohio]

Aguyfromohio,

Thank you for the very informative post.

You are most welcome.

It's helpful to double check for tried-and-true solutions. For a super lightweight vehicle, look at home built aircraft, racing boats, and racing cars.
Those folks are relentlessly creative and innovative, the approaches they use are probably the best ways to build a lightweight sturdy vehicle.

The construction techniques they used in years long ago are pretty good too, often nearly as effective as the current state of the art but cheaper and easier for the home builder.

[dogcatcher]

I agree that PVC is not the best choice, but I suggest checking in Google for PVC built pedal cars, go karts and trailers. Sun is the worst enemy of PVC, the UV's make it brittle.

[John61CT]

and super difficult to get a protective coating to stick to it.

metal electrical conduit would be better IMO, strategically reinforced with structural but thin-walled rectangular tubing oriented long way in the stress direction

don't need to weld with modern adhesives these days, or bolted strapping, or wire wrapping with Clamp-tite, or combining these