Their weighted in the top, so as soon as they are peturbed, they "roll" uphill.
One of them even slows down after hitting the next tire, and then starts rolling again.
There appears to be something on the ramp to keep them in their initial position, so, yeah, weights along the rims would make them accelerate as the weights moved out towards the horizontal from the rim center, and then slow down once the weights passed the horizontal.
I think I'll disassemble my Accord to see if I can duplicate it all.
= )