Lugs, ribs and their impact on your tires

Michelin factory worker working on tire treadWhile a truck’s application plays the primary role in selecting a tread pattern, there are really only two options: lug and rib.

Greg Kidd, Sales Engineering for Bridgestone Americas Tire Operations, says lug patterns can be closed or open shoulder design, and are typically used on drive axles. Typically, closed shoulder lug patterned tires feature wide shoulder ribs to promote longer mileage and even shoulder wear. Open shoulder lug pattern tires have blocks on the shoulder instead of a continual shoulder rib and their design features a more aggressive look for increased traction in rain mud and snow.

Rib patterns can be straight or zigzagged, and typically are used on steer and trailer axles.

“A straight rib pattern is designed for high mileage, good fuel economy and resistance to irregular wear,” he says. “They usually have a ‘defense groove,’ a straight groove cut into the shoulder rib which aids in resisting irregular shoulder wear.”

The zigzagged pattern, Kidd says, offers additional biting edges for improved traction on wet road surfaces.