The kobuki base on your own isn't going to drift, so it is smart which the tilted inertia causes the drift. Needless to say I am able to hack my URDF using a weightless superstructure, but I planned to deal with this in a more realistic way. I tried all https://www.uk-exhibitionstands.co.uk/product/monolith-2m-display-wall-2-4x2-2/