It's a motorcycle with jets in its wheels.
Earlier I eviscerated Rosa Motor Company's Kirby hoverbike. It is physically and legally impossible for it to live up to its bold claims. Now Lazareth, the French company known for putting a Ferrari engine in a quad, is teasing us with a video of a hoverbike of its own. While some of my criticisms of the Kirby still apply, one notable difference is that we may actually see this bike in action sometime soon.
On the surface, this idea seems almost as ridiculous as the Kirby. The teaser video shows it being ridden on the street like a regular motorcycle—well, a motorcycle with four wheels, anyway. When the rider parks, the real magic begins. Each wheel tilts up and rotates to a horizontal position, much like Doc Brown's DeLorean in Back To The Future. That's when we see that each wheel contains a small jet engine inside its hub. When the wheels go horizontal, the jets are vertical and fire up to levitate the bike above the ground.
Like the Kirby, jet engines are loud, and four of them could generate almost a Boeing 747's worth of noise, which is a problem. The main difference between the Lazareth and the Kirby, though, is that the Lazareth might actually work in the real world. Rather than using jets to accelerate the bike to ludicrous speed, the Lazareth points them downward to provide lift. This method of hovering has long been proven to work on vehicles like the Harrier jet fighter. Presumably, each wheel tilts slightly to propel the bike in various directions when it's in hover mode, rather like some propeller-driven hoverbikes and drones.
We don't know anything beyond what's shown in the video at this time. However, Lazareth promises to launch the bike on January 31, 2019, which means we should see it a darn sight sooner than if/when the Kirby comes out.