Originally Posted by
EvilV
It is the most upright bicycle I ever rode my friend.
What does sitting upright have to do with the price of tea in China? Weight bias have nothing to do with it either. Speaking with no scientific background what-so-ever, take this with a grain of salt.
At the point in which a bike's deceleration generates enough force to pick the back wheel up off the ground, only two things matter, assuming nothing "funny" is going on.
* The center of mass in relation to the front fulcrum point (axle plus tire radius)
* Inertia of the entire moving mass.
You can sit bolt upright on the handlebars of a "normal" bike, and you're still going over when you hit that pothole. Similarily, you can have 70/30 weight bias over the front wheel on a "pedal forward" recumbent and never need to worry about flipping over.
Originally Posted by
EvilV
It should be fairly obvious that these "stunts" were deliberately performed, the former from kids screwing around, and the latter to comical effect. The dead giveaway is how each rider was able to avoid jamming his knee or thigh into the handlebar. When's the last time you performed a split when stopping your bike?