Not sure what all is involved to make a supermotard.. I believe it's a smaller rim in front, smaller rear sprocket, then the slick tires? Beyond that not sure how to bring it back to dirt status.
82 fj40, 99 uzj100, 06 gx470
97 DR650, 05 525EXC, 06 TW200, 89 TW200, 09 TTR125, 07 TTR90, 07 CRF50