As for inanimate things that have been designed to move, use the Max Speed listed in the Vehicle Systems in Mage 20, Chapter Nine, pp. 460-462 to determine how fast a given vehicle can move before it starts to fall apart.

Above that Max Speed, the vehicle can withstand one success for each point of Durability it has. A dirt bike with Durability 4, for example, can withstand up to four successes (four times its Max Speed) before it begins to break.

Above that limit, the vehicle loses one point of Structure per turn. Once that Structure is gone, say buh-bye to the vehicle and anyone who’s unfortunate enough to be in it.

Please note – these stress-rules are based upon drama and simplicity, not real-life physics. Actual bodies and vehicles fall apart a lot more easily under intense motion-stress.