[aerohead]

This is close to how BamZipPow's one-wheeler is configured, but with a very important caveat.
Since his attachment system does away with any need for 'roll' and the wheel pivot is perfectly vertical, his wheel fairing cannot strike the belly of the trailer when turning.
If the wheel were suspended on an angled lolly-shaft, as soon as the wheel turned, it would be in interference with body and the fairing would be ripped off immediately.
Since the fairing can cut the wheel drag by up to 70%, it's vitally important to protect it.
I've limited my rear wheel to only vertical displacement, as a simplifying means.