I was sitting here in the bush writing and overheard a conversation between a he and she as they discussed their rides. They were both riding road-registered dirt bikes and he was having a problem.
She found her bike to be perfectly stable when running hard or jumping. He found his bike to be the same. What he couldn't get his head around was when riding her bike, ostensibly the same size and weight, he found it hard to control and almost dangerous when riding hard or in mid air. She found his desciption of "death wobbles" funny and couldn't see the problem.
Look at them.
He: Barrel chest, "thick set", small butt and skinny legs, tall. Classic upside-down pear.
Her: Slim chest, larger hips and thighs, shorter. Classic pear.
She has obviously chosen her bike because she can ride it comfortably. He has done the same. The bikes are different geometrically; you can see just by looking from a distance that they have different centres of gravity.
So do their riders.
It makes perfect sense to me that the combined centre of gravity works for each on their own bike. Apparently he, on her bike, looses control. He can't understand it.
I wonder how many people buy a bike without considering the mechanics of the combined centre of gravity, and wonder why they never quite feel comfortable? How many buy a bike because they like the look or style, or to match the one ridden by some other person, without considering that they actually have to ride the thing?