They're 21x12x10 6 ply and they're hard as hell because they still have the nipples on them. Only ridden on them like 4 times.

I like how your quad sits on the 21,s.That tread pattern looks like it would really dig on.I,m running 20" Razr,s and they,re getting shredded like tissue paper.lol Might try a different tire.Seems the 500,s eat tires fast with all that torque.