Shimano knew that the naysayers who questioned the fad for an 11-speed cassette were simply out of touch with the needs of the modern rider. As a result, they developed the Shimano Dura-Ace CS-9000 Cassette to be the centerpiece of their “rider tuned” philosophy, offering eleven gears and a phenomenally wide range of gear ratios to suit the requirements of each rider.
In spite of the fact that they added a gear to the drivetrain, the cassette is nevertheless just a breath heavier than the 10-speed 7900 version. They managed that sleight of hand by including some top-drawer materials into the mix. First, the four largest sprockets are made from titanium to reduce weight and enhance the rigidity of the set-up. But something new is that they have made the mid-spider carrier out of carbon fiber instead of aluminum. The innovation keeps everything working smoothly with the added advantage of shedding important grams.
Shifting quality has always been a badge of honor for Shimano, and they have lost none of their mojo by adding the eleventh cog. The storied Hyperglide shifting system has been tested and refined over the years to the point where there simply aren't any miss-shifts. The chain moves smoothly from one cog to the next without any override. The computer-designed sprockets incorporate shift ramps and tooth profiles that are specifically positioned to have a firm control over where the Shimano Dura-Ace CN-9000 Chain will glide while shifting.
Shimano calls it “rider tuned” largely because you can chose from 11-23,11-25, 11-28. 12-25T, and 12-28 options. The 11-28 cassette in particular is one of those have-it-both-ways options that makes riding a lot more fun. Now you can churn your way up a long, steep climb, and still enjoy the ride down without spinning out. That’s just one of the examples where Shimano shows its sympathy for the real-world riders: they may sponsor many of the greatest cyclists in the world, but they still take all that research and feedback and transform it into something that will benefit every weekend warrior.
To fit that extra gear in there, Shimano managed to make the hub a touch wider and the chain a touch narrower. On the slight bummer side, adding the width means that a Shimano 11-speed cassette cannot be used on a 10-speed hub. However, a 10-speed cassette can be used on an 11-speed hub so long as you add a spacer.
If you haven’t tried an 11-speed cassette, if you still are using your 8 or 9-speed Dura-Ace and wondering what all the fuss is about, just one session on a bike kitted out with the Shimano Dura-Ace CS-9000 Cassette and its 11-speed drivetrain system, you’ll wonder how you ever lived without it.