The tread design and the sticky Black Chili compound make the tires grab like Velcro on rocky terrain, and this also aids in braking. Tractor pulling power! The only place they don’t do as well as expected to be on long slick rock sections, where their brethren the Mountain Kings are champions. The lugs have some deeps sipes in them, which helps in wet conditions and aids greatly in traction and braking.
Siping is a process of cutting thin slits across a rubber surface to improve traction in wet or icy conditions. Siping was invented and patented in 1923 by John F. Sipe. The story told on various websites is that, in the 1920s, Sipe worked in a slaughterhouse and grew tired of slipping on the wet floors. He found that cutting slits in the tread on the bottoms of his shoes provided better traction than the uncut tread. Sipes are fairly ubiquitous on winter, all season and all terrain vehicle tires.
The girth and weight of these big tires do have a drawback, they are requiring more work while climbing, and they only have decent rolling resistance. The APEX sidewalls gives a lot of strength and stability to the front end when steering through difficult terrain, plus it keeps the rear planted firmly to the tarmac. On occasion though, you get a sideways ricochet off rocks, roots and debris. The sidewalls are very beefy, and I never had any cuts nor abrasion issues. I did seem to pinch flat every couple of weeks, and would have a flat tire after I completed my ride, so at least the pinch caused a slow leak. Due to the large size the tires do steer slower, but they roll well enough that you can bring the tire around as needed.
On occasion the tires would wash out while doing hard cornering in looser terrain, and they preferred to be tilted up taller in corners, more like how you ride a Superbike on a race track. If you happen to get the tire in the proper groove they carved very sweetly, but you really had to roll them over deeply. I can’t recall a tire that carved as nicely as they do when they are in the sweet spot.
The tires hooked up well while pedaling and climbing in gravel and loose conditions, and they floated over sand quite nicely. Even though they weren’t the best rolling tire around, they did perform fine on hardpack. They did well in mud due to the widely spaced tread pattern, and the lugs helped you power your way through the slop, and they seemed to clean fast. Although they did decently in the snow, they were a little more slippery than normal on ice.