Silence44 action the new chorus 11 speed chain is quieter than everthe new 55 millimetre thickness has been combined with new materials and a special anti friction treatment which permits outstanding fluiditywe have reduced the width of the chain to 55 millimetres with the new spacing and a new material has been envisaged for the outer links the pins are hollow inside to reduce the weight while maintaining strength it is necessary to use tool ut cn300 to fit it the ni ptfe treatment