Shimano Dura-Ace CS-R9100 11-Speed Cassette

Core has plastic NOT carbon fibre, hence why it breaks. Truth is the carbon spider thing is a marketting gimmick that breaks the truth test- and literally. Cogs attached to it flex and bend resulting in bad unintented torque drops under load, DING! The wide 5.8mm Shimano chain catches adjacent cogs. Even the 5.3mm Campy, which runs silent, will still bend this plastic mounted cogs, and drop under high load. Spacing is inexistant, and the metal is poor quality. Just several levels below the Campy XG-1190 - on one bike I have had one for 14,000 kms and it is still flawless. As it is well documented, the inner core does snap under load, tying the cyclist forever with Shimano back and forth. For a true solution to this cassette, check pics: SRAM XG-1190, Campy chain, and the new Shimano RD9100. No DA cassette, no Shimano cables. System runs powerful, silent, never grinds drops or catches. In the picture, the cassette has 14,000 kms and just replaced it. Now, if driven at 27-30km hr max, with slow climbing, it might pass the test. But 30-50km/hr with acceleration, it fails

Core has plastic NOT carbon fibre, hence why it breaks. Truth is the carbon spider thing is a marketting gimmick that breaks the truth test- and literally. Cogs attached to it flex and bend resulting in bad unintented torque drops under load, DING! The wide 5.8mm Shimano chain catches adjacent cogs. Even the 5.3mm Campy, which runs silent, will still bend this plastic mounted cogs, and drop under high load. Spacing is inexistant, and the metal is poor quality. Just several levels below the Campy XG-1190 - on one bike I have had one for 14,000 kms and it is still flawless. As it is well documented, the inner core does snap under load, tying the cyclist forever with Shimano back and forth. For a true solution to this cassette, check pics: SRAM XG-1190, Campy chain, and the new Shimano RD9100. No DA cassette, no Shimano cables. System runs powerful, silent, never grinds drops or catches. In the picture, the cassette has 14,000 kms and just replaced it.

This thing belongs in a jewelry box or on display under glass. I am floored by the quality of this cassette.
Update: I have now put several thousand miles on this cassette; still a 5 star in my opinion, love it. Smooth and incredibly precise shifts. Lighter weight. Awesome!

I have 4 11 speed bikes, 2 are Campagnolo super record and 2 are Sram eTap, after spending way to much money on Campy and Sram cassettes I accidentally found out the best shifting, best gear ratio (same ratios as Campy except Shimano gives you a 28 to Campagnolo`s 27 and Sram starts to triple the big sprockets way to early), quietest running, almost the lightest (Sram is a bit lighter) cassettes you can buy and they are the least expensive by far. half the money of the Campy SR. a quality source told me this 2 years ago and I arrogantly didn't listen.. da

I bought this DA cassette trusting Shimano's unwavering quest for quality. On that, Shimano never disappoints. Now I can run my 50/34 chainring and have plenty of gears to spin up the climbs around Park City. Guardsman, here I come.

2017 S-Works Tarmac eTap. On a tech’s suggestion, I ditched my SRAM Red cassette for the Dura Ace. Immediately solved noise and occasional hung shifts. 300 miles in. Drivetrain is whisper quiet and rock solid now.

Works great on my Shimano, sram and campy groupsets.

Great fit travel to the mountains

I decided to go with the size 12-28 to replace my ultegra cassette and I am shocked by how much better this Dura-Ace cassette is in comparison. The sizing is better and the shifting is smooth.
Finally, I was impressed how cool the packaging was too!

The 9100 cassette carries the same Shimano quality we all have learned to expect. Switched from an 11-28 to this 12-28 and am very pleased. The marginal amount I have lost on the top end has been greatly outweighed by the addition to the 17 tooth in the middle of the block.