A tread for a tire includes a first circumferential main groove, a second circumferential main groove, a third circumferential main groove, and a fourth circumferential main groove. The fourth main groove has a stabilizing structure for increasing tread stiffness. The stabilizing structure has a circumferentially extending subgroove in a radially innermost bottom of the fourth circumferential main groove. The subgroove is axially offset a predetermined amount from a centerline of the fourth circumferential main groove.