A method of correcting or reducing a conicity or a mass distribution imbalance of a tread strip (132), wherein the method comprising the steps of extruding a tread strip (132) having a right hand side, a left hand side and at least one chimney (32, 304, 312); measuring the thickness or the mass of the tread strip (132) at the right hand side and at the left hand side; and, if the thickness or the mass of the tread profile (132) at the right hand side and the left hand side is different, adjusting the location of the chimney (32, 304, 312) or the width of the chimney (32, 304, 312) in such a way that the difference in thickness or mass is reduced; furthermore, a system for practicing this method is disclosed.
