3D printed RC spike tires - too dangerous to release into the wild…
but check out the other 36 combinations of printable rims & tires:
http://www.thingiverse.com/thing:526969/
https://cults3d.com/en/game/set-of-wheels-for-openrc-truggy
http://www.youtube.com/watch?v=brwortuYGuM