Disclosed is a tread for a pneumatic tire. The tread has a plurality of grooves. The grooves have a base defining the depth of the groove relative to the tread surface, opposing groove walls, and a centerline equidistance from the opposing groove walls. The groove may extend in either a circumferential or a lateral direction of the tread when the tread is applied to a pneumatic tire. At least one of the grooves has a plurality of spaced projections in the base of the groove. The projections extend from one groove wall to the opposing groove wall and are inclined relative to the groove centerline at an angle of 10 to 50. The projections have a pitch length measured at the groove centerline of 0.75-1.25 the projection length as measured along the groove centerline. The pitch length is the length as measured from one point of the projection along the centerline to the same point in the adjacent projection.