If one is riding a motorcycle at almost 300 km/h they're still stuck to the bike because of gravity pushing them down into it.

 

What would happen if the bike was somehow exceeding 800 km/h? Would the rider be blown off? Crushed under the g-forces? What?

If one is riding a motorcycle at almost 300 km/h they're still stuck to the bike because of gravity pushing them down into it.

 

What would happen if the bike was somehow exceeding 800 km/h? Would the rider be blown off? Crushed under the g-forces? What?

What would be the source of the g-forces? The 800km/hr alone won't tell you that. Or do you mean pressure from the apparent 800 km/hr wind?

 

800 km/hr is certainly well above the terminal velocity of the body when falling (in 1 g) in any position, so without blocking the wind, or securing the rider in some way, he/she would most certainly be blown off

Even at speed below 300km/h I should think that the bikers grip on the handle bars and leg grip on bike and stirrups play an important role is stopping the biker not being blown off the back of the seat.

A fairing would protect the rider from the wind.

 

To use an interesting example, here's the famous electric motorcycle dragster named Killacycle reaching 60 mph in 0.97 seconds (almost 3 g's) and reaching 168.49 mph (about 270 kph and 250 fps) at the end of the quarter mile. One moment, you can reach out and touch the rider, and the next moment, he's simply gone, gone, gone!

 

If one is riding a motorcycle at almost 300 km/h they're still stuck to the bike because of gravity pushing them down into it.

 

What would happen if the bike was somehow exceeding 800 km/h? Would the rider be blown off? Crushed under the g-forces? What?

 

Gravity isn't going to "go away" from going 800 km/hr. Orbital speed at the earth's surface is around 8 km/sec, or 28,800 km/hr. He's only going to be pulling a fraction of a g more if he goes the opposite direction.

Okay, so 800 km/h really is more dangerous than I thought.

 

How about 600 km/h? Is that too fast?