When installing the trapezoidal outer wire, relative twisting occurs at both ends, which often leads to misalignment of the flange holes at the connected ends due to installation errors, resulting in displacement. It is thought that the trapezoidal outer wire can withstand torsional displacement compensation, but in reality, it cannot compensate for this torsional displacement on its own. If there is a significant radial displacement at both ends of the outer wire joint during installation, although the outer wire joint itself can compensate for lateral displacement, if there is a significant relative radial displacement at both ends during installation, it will reduce the actual compensable amount in that direction, which may cause the required compensation amount in that direction to be greater than the actual compensable amount of the joint in that direction during use, resulting in fatigue damage and damage to the joint.