You don't have to look very hard to see how many 4xJockeys are shoeing their rigs with big, knobby mud tires for everything from commuting to radical boulder bashing. The hunky meats certainly look cool, and they work extremely well for mud and almost every other type of condition.
Almost is the key word here. The big, sometimes scary exception is loss of traction on wet or otherwise slick pavement and on ice and snow. Those chunky lugs grab OK in loose or slushy snow, but ice or even just wet surfaces can make you feel a little queasy.
In response, increasing numbers of off-roaders are turning to siping as a way to increase traction. But what exactly is siping? How much can it really help? Is there a downside to siping? And how is siping done? To answer these and other questions, we visited two sources: Offroad Design and Discount Tires. Here's what we learned.