Shimano Dura-Ace R9110 Direct Mount Rear Brake Caliper When aerodynamic efficiency is as important as braking power, look no further than the Dura-Ace BR-R9110. The most advanced groupset ever: Shimano Dura Ace Brake Caliper BR-R9110-R Direct Mount Two braking options now exist for riders at DURA-ACE 9100 level - mechanical rim brakes or hydraulic disc brakes. Hydraulic road disc brakes in the new DURA-ACE line-up add an extra element of control and confidence to brake performance in tough (weather) conditions. Dual-pivot or Direct Mount type rim brake calipers bring incredibly powerful performance, offering the best balance between rigidity, weight and stopping power, providing a sleek design, bringing better clearance for tires up to 28c and a 43% reduction in flex over previous DURA-ACE brakes. Direct mount options provide integrated aerodynamic designs at the front (BR-R9110-F), on the rear seat stay (BR-R9110-RS) or under the bottom bracket (BR-R9110-R).