Ghislain, >Ray, according to your theoretical works, and providing my input is right, >stable conditions on this python should appear at 25 kmh ! I could not get it to look "self stable" at all from your description, but that is not the same thing as ridablility. Try riding it without your feet on the pedals, or just resting them, and not trying to control with your hips; that is what the program tries to calculate. Of course, my python is nowhere near "stable". Even with me riding it! ;-) Ray ============================================================ This is the Python Mailinglist at freelists.org Listmaster: Juergen Mages jmages@xxxxxx ============================================================