Warning eps groupsets will not work with 1129 cassettes please use 1229 insteadevery sprocket tooth has been designed to achieve the maximum synchronization shifting speed and silent operationthe six larger sprockets have a double frame system for extreme torsional stiffness so that operating precision is maintained even during shifting under stressthe surface treatment of the 11 steel sprockets assures longer component life maintaining the maximum long term performancetechnical specific