That is cool and I've just had a look at the site. If they were road legal over here then I would have something like that to play with and Im surprised I have not seen them here. But it does not fit in with my brief on the ZORB.
The reason Im building it from an MTB is for failure and loss of resources in the end. When "The Day" arrives and it all stops It would be a fully running motorised bicycle once fossil fuel has gone or I have no access to it the engine just unbolts and is dumped then you are back with a standard MTB once all parts to keep the bike running are gone it gets dumped and then your back to the bergan on your back and boots on your feet.
This is why I don't have a trail bike etc for this scenario as once you run out of all forms of fuel for your rokon, land rover, jeep etc it is just a big heavy paperweight. At least the bike will get lighter and there will be spares in every town and city on this earth from any $99 stock MTB.
That why I am building it.