19 x 1.85 x 2.75 dual sport motorcycle tire, but dimensions are different, so more like 25" outer diameter, compared to 27" hookworm OD.

just put up a highlights vid for the year that has some scenes w/ me working on the wheel: www.youtube.com/watch?v=UZZQhX1mlXU

 sick that is pal. wat size tire is that on the back ? ..