Finally was able to get out for my first ride on the IRC tubeless trials tire that I mounted up on my 426 using an 18" WR wheel that I got from Moto2000 and it was incredible. In short...this tire rips. It is incredible, it's like having an extra inch of suspension and it absorbs and grabs onto everything it rolls over. Tight single track with mud, rocks, and tree roots was a breeze. This thing did not slip unless I wanted it to. Wet tree roots while cornering? No problem. Riding up a dry streambed of softball-sized rocks with a 1/2 inch of snow on top? No problem. Here's a quick video of us going up a powerline road that was loose gravel covered with loose semi-compact snow and ice on it. The two bikes with knobbies had to be manhandled up the hill and pushed the last 50 yards. With the trials tire I motored right up...the videographer did not appreciate the fact that I didn't have to get off and push like he did as you can tell by his comment http://video.google.com/videoplay?docid=7848196241357492629 By the way, both my YZ426 and my buddies YZ450 run Rekluse clutches.