The Ecomobile and its close relative the Monotracer are enclosed motorcycles. The enclosure makes them safer in accidents and immune to the weather. The enclosure means that you need a way to keep the motorcycle upright when it is standing still, so there are retractable outriggers. You can see the Ecomobile in action in these videos:
According to the video, the Ecomobile comes with a 1,000 cc or 1,200 cc BMW engine that gets 60 MPG.
And the Monotracer:
If you are looking for an enclosed motorcycle with a little more spunk, there is the T-Rex: