Most off-road bikes work best with knobbies, but some riders have mounted one of the modern radial-ply trials-type tires for superior handling in certain conditions. The more technical a trail becomes, for example, the more a trials tire will out perform a knobby. With more power getting to the ground, a stock KLX can feel like a 340, and that's good news! It's controversial, of course, and perhaps always will be, but here are some things to consider when you're looking for a new set of shoes for your KLX...
Knobbies get their "bite" by digging into the ground and pushing, whereas a trials tire gets traction by wrapping itself around the rocks and roots and rolling over them.
On typically "slippery" surfaces, such as dry weeds, wet rocks and pebbled roads, a trials tire flattens out more than a knobby to give you a better bite -- the more "technical" a trail becomes, the more a trials tire will out perform a knobby.
Trials tires do not, therefore, break loose as easily or as predictably as a knobby, so you probably would not choose one for sliding around corners or for any situation where you need some wheel spin
But you can learn to slide the KLX with a trials tire -- it just takes practice, a deeper angle and a firm desire to make it happen
And a rear trials tire will break loose in a more predictable and controlled way with a trials tire on the front to keep the front firmly planted while you're swinging the rear through a turn
You should adjust your suspension differently for a trials tire than you would for a knobby
Since trials tires flatten out more than a knobby, they give the rider more "cone" effect in turns. Take one of those paper cups you buy coke or ice tea in -- small at the bottom and large at the top. Toss it to the ground. Give it a kick. See?
Knobbies have a stiffer sidewall, and therefore provide more protection against flats due to a slashed sidewall than do trials type tires
But you can minimize "pinch" flats in a trials tire by installing a tubeless trials tire (which has a stiffer sidewall than the tube models) with a heavy duty tube, such as the 4 mil Bridgestone Ultra Heavy Duty tube
You can use as little as 6-9 pounds for maximum traction, but 10 lbs is recommended to minimize flats
Trials tires are easier to mount than a knobby, but the bead comes off the rim quickly with a flat -- you won't be riding back to camp on a flat trials tire, so be prepared to replace the air by one method or another.
Keep a close eye on your spokes -- the more flexible sidewalls on a trials tires seems to put more forces on the rim and accelerate loosening of spokes.
Keep a close eye on the valve stem. Install the tube so the stem leans forward slightly when at the bottom position. If you notice it leaning backward, your tire is slipping on the rim. Try a wider rim lock or insert a small strip of inner tube between the bead and rim at the rim-lock location.
Trials tires do not handle big whoops as well as knobbies do, and some are "squirmy" on paved or hard-packed roads, so they're not the best choice for wide open desert or dual sport events with easy trails and occasional highway riding.
The IRC TR11 and Mitas ET-01 D.O.T are apparent exceptions to the wishy-washy feeling on paved or hard-packed roads. The Mitas is more knobby-like in handling than the IRC or X-11, and the side knobs hold better in conditions where side knobs are needed, but it breaks loose more easily, which explains why it wears more quickly. The Dunlop D803 is the new kid on the block, but one KLXer got 1,875 miles of service out of his...
I've tried four brands and the D803 is the only one I've bought two of. It is cheaper, but I'd get it anyhow at the price of any of the others. I still think the X-11 has an ever so slight edge on inline traction, but the handling for average trail riding makes the D803 a clear choice for me. Wear has been a little less than the X-11 but about the same as the IRC. Better traction than the IRC and also less squirm. Somehow Dunlop has considerable "squat" in the lower part of the sidewall while the upper part retains enough stiffness to eliminate squirm. Or something. Whatever they did, they got it right-for trail riding. But don't let anyone sell you an 801 -- they shred in about 4-500 miles...
The trials tire with the best wear has the best traction but the worst side knobs and the least overall knobby feel...
The more "technical" a trail becomes, the more a trials tire will out perform a knobby...