Shimano's Dura-Ace 9100 mechanical groupset has many exciting features that distance it from it's 11-speed forebear, 9000. For many cyclists, the high-polish painted black to pewter finish will stand out for aesthetics alone, but there are substantial changes, and the new short cage rear derailleur delivers some major advantages. First, it adopts the Shadow compact profile and cable routing from the XTR mountain design. Second, it has a slightly longer cage, allowing it to pair with the new 11-30 wide range 9100 cassette. Third, the engineers carried forward the direct mount option used in the mountain bike design. Clearly Shimano see's the movement towards thru-axle rear triangles in road bikes incorporating the direct mount option, which eliminates the B-link assembly and pivot, creating a stouter interface between frame and derailleur that results in even crisper shifting.

The rationale behind the Shadow style derailleur is simple and has clear benefit to all cyclists. The design sits much closer to the frame and under the cassette, protecting the cage from ground contact in case of accident or from bike to bike interaction when transporting multiple bikes. The pathway the derailleur action travels when shifted is also more linear, and smooth. Combined with refinements in the 9100 shifter mechanism, a shorter throw results in quicker, more precise shifts with less effort, even over the wider spread of the 11-30 cassette. Adding that greater range opens more cyclists up to Dura-Ace precision and refinement- the best mechanical shifting available, period. One important difference between the mountain and road application of the Shadow design is the presence of a compact barrel adjuster for manual cable tension adjustments. The B-link standard hanger mount can be uncoupled from the direct mount pivot if your frame accepts the direct mount system.

Dura-Ace quality means the best hardware: springs, pivots, fastening bolts; as well as lightweight, top performance and durability over hard use. Shimano's long experience with forging, machining and casting aluminum allows the engineers to make the body, links, and axles stiff, strong and light. Flouric coated link bushings keep the movement smooth and the linkage torsionally stiff and aligned. The cage plates are made from Carbon Fiber Reinforced Plastic (CFRP), which lightweight, stiff, and resilient while not being susceptible to weakness resulting from wear that would damage directional carbon fibers. Lighter and more durable than comparative thickness and strength if made from aluminum, when molded into shapes and fastened properly, the resulting clear-coated CFRP cage is torsionally and laterally stiff, resulting in reliable shifts and chain performance under load, no matter what ring and cog combination you find yourself in. The upper and lower pulley wheels have specific profiles, and ride on SUS stainless steel bolts, among the highest grade stainless options made.

The design and function of the RD-R9100 rear derailleur are wholly integrated. There is no form without function. Clean, sleek, light, and strong, the derailleur guides the 11-speed HG-EV or HG-X11 chains through the full range of any compatible cassette with ease and precision that is the hallmark of Dura-Ace. Shimano considers the system integration of 9100 to be the highest level achieved to date, with every click, cable movement, actuation, indexing, and shift result the ultimate in systems engineering. Every single aspect of the system is designed and engineered to complement and function as a unit. Examine the teeth of the pulley wheels, then the links of the chain, and ramps, chamfers, grinds, and profiles of the chainrings. You will see the results of decades of innovation, patent development and pure science in the engineering. Why invest in Dura-Ace? Any cyclist who seeks flawless operation that is reliable and represents exceptional precision knows why. With the highest, practical quality materials, long term durability of the components is expected.

Choose the Dura-Ace RD-R9100 Rear Derailleur for your new 9100 mechanical drivetrain build, or upgrade your 9000, 6800, or 5800 drivetrain to gain the Shadow advantages. Many 9000 users will upgrade to have optimal use of the new 11-30 9100 cassette. Cable pull ratio is fully compatible and performance is not only seamless, but improved. That is an upgrade worth celebrating.