You mean to say this could be the improved version? Dios mio... We need two people if we want the cart to make it five meters through Black Forest. One is "handing" the cart, the other with an axe, a pickaxe and a hoe is paving the way.

A 5 degree inclination or a twig sprung from the earth is all it takes to grind it to a halt. How much does the weight affect its movement?