Just mounted the Kenda's on Monday. Road the bike to work on Tuesday(27 degrees F in the am), I took a 1 mile river trail section with hardpack, sand and few small jumps/bumps. These tires work unbelievably well on the blacktop, and they are not even broke in. The bike is still smooth, likes to go straight, stable up to 75 mph(fastest I went so far) and competent in the corners. There were no suprises, they are totally predictable. On the way home from work, I decided to give a favorite single track that is 6 miles long a try. I love this trail on my XT. Along with the smaller front sprocket and the awesome knobs, and upgraded front suspension, this bike is quite the trail bike for being 540 lbs. I tried a loosish hill climb last week with the T66's and made it half way. Yesterday I shot to the top with autority. I am having to re-learn how to ride the Tiger off-road, it is a hoot. I climbed a very loose sand dune that is about 35 feet high. It was simply amazing how the bike roosted to the top with out having to dab! Then I rooste to the top in 2nd gear at about 7,000 rpm! Coming down the dune was very predictable and actually fun. I then got into the woods section, complete with tree roots crossing the trail at all angles. The bike tracked straight. I then started getting comfortable with riding like I was on a much smaller bike. I completed a trail that I never thought I would do on the Tiger. I recommend the Trakmaster II's to anyone that doesn't mind loosing some on road manners, but gaining 10 fold offroad ability.