Shimano dura ace 7900 double 10sp chainsetwith a unique four arm spider and hollowtech ii construction putting strength just where its needed the dura ace 7900 chainset sets new standards for stiffness and low weight the hollowtech ii 10 speed dura ace chainset offers the optimum balance of light weight and rigidity making it the global choice for road racings elite riders please note bottom bracket is not included featuresshimano has raised the bar to a new level ofperformance with the de