Shimano dura ace r9100 p power compact chainsetthe shimano dura ace r9100 p power compact chainset has been completely re designed to offer the very best combination of light weight and stiffness it features shimanos iconic 4 arm hollow spider that is made from hollow forged aluminium a first for shimano this model is also equipped with an integrated power meter with bluetooth and ant connectivity providing you with in depth power data to help to analyse and improve your performance accura