Motorcycle rear wheel. Innovative for he has a solid disc motorcycle rear brake maybe hydraulic yet. Engine drives off a jack shaft. Just the sheer size of the engine makes this a win but it also makes this a motorcycle with just one gear.
It needs a CVT. Shouldn't be too hard to add on.
That thing would attract attention...from 'The Man'. It looks and sounds like a motorcycle and would need tags, insurance, etc, etc, in Colorado.
But it sure sounds good. I'm glad he uses a good muffler.