Bikes these days typically make at or over 1 HP per 10cc's. A 500cc bike could very well be cranking out 50 horses. If the bike weighs 300 lbs and you weight 200, that's 10 pounds per horse.
A 5.0 Mustang makes 215 horses and weighs right around 3700 lbs with a driver and fuel. A little over 17 pounds per horse.
I think the Valk's about 700 lbs. Call it 120 horses, although I'm sure it's a bunch more. 900 lbs of bike and rider and 120 horses=7.5 pounds per horse. Extreme stuff.
For comparison's sake, my 99 KLR650 is something like 337 lbs and makes 41 horses. Granted, it's got a lot more torque than horsepower being a single-cylinder engine, but geared as tall as it is, it can still wheelie in 3rd gear. About 13 pounds per horse and it can still seriously get away from you.