Can't say I haven't fallen off anymore...

[Ocean1]

But the bike-rider system's center of mass and moment of inertia depend entirely upon where in space the mass is.

Indeed....

[jafar]

An interesting memory is that back in the day, some Briddish iron used to have the pillion pegs mounted directly on the swingarm. So, if you stood on THOSE. you transferred all your weight from sprung to unsprung weight. A useful trick in heavy going.

Harley Davidson still do this even on some of the new ones

[xwhatsit]

Even Suzuki A100s have them on the swingarm. Actually not as bad as I thought it would be. Quite a sensible place to mount them, that way you don't need long brackets like rearsets.

[jrandom]

polar moment of inertia

[Motu]

I think if you got a little closer to those polars...you would find out quickly they react.Large polar's can be rather savage in their reaction.Large polar reactions bite - 911.....or VW Beetle if you have a lower budget.