Everyone that owns a 700XX knows the biggest drawback when trying to MX the quad is, IT WONT TURN. The IRS just gets too much traction, plus it's next to impossible to run an 18" tire setup. We have found the solution. We are now running a set of Douglas front beadlocks size 10x6 (4" back spacing) with a set of old Armstrong Fast Trekker fronts sized 21x7x10. Essentially the tire is 19" tall when mounted. The narrow tire provides just the right amount of traction and the 700XX still comes out of the hole great, plus it can now be pitched sideways like a straight axle. This dramatically improved the handling of our 700XX on the MX track. It's very controllable and much funner to ride.
These Tires are now made by Titan: