Shimano dura ace r9100 road brake caliper setthe dura ace 9100 brakes have been developed to offer greater tyre clearance for up to 28c tyres while still maintaining the aerodynamic advantage of previous editions they are now also up to 43 stiffer than previous dura ace brake calipers and offer a linear braking curve for improved feel and function the quick release arm now tucks in toward the main body when closed for improved aerodynamics features mount type slr ev dual pivot the best bal