The kobuki base by yourself does not drift, so it is smart which the tilted inertia leads to the drift. Not surprisingly I am able to hack my URDF using a weightless superstructure, but I planned to fix this in a far more realistic way. I tried all I'm able https://www.uk-exhibitionstands.co.uk/product/casonara-blimp-rectangle-360o-hanging-light-box-display-100m/