I assume you're referring to cable housing rubbing the head tube. One solution I'm using is to install the cables so the cable from the right side of the bars goes around the front of the head tube and into the cable stop on the left. The cable from the left goes around the front and into the stop on the right. Then the bare cables cross in the middle of the downtube on the way to the guide on the bottom bracket. This routing not only keeps the housings from grinding on the headtube, but it also produces smoother curves in the cable housing, substantially reducing the amount of effort required to move my shift levers.