KCNC Road Cyclocross Gravel Bicycle Bike Rear Derailleur Oversized Pulley Wheel System Cage OSPW for Shimano Dura-Ace/Ultegra 6700/6770/6800/6870/7900/7970/9000/9070 use in Black/Red/Gold Colors

I cannot recommend this product. The cage causes my drivetrain to skip whenever power is placed into my pedals. It happens when I take off from a stop, change gears, cross-chain, or shift under pressure. I have a new chain, cassette, and chainrings. They worked just fine prior to the install of the cage. I changed the tension and aligned my derialluer hanger, all to no avail. After five weeks of experimenting, I'm done trying to get it to work. FYI, the return policy is 30 days.With all that said, it is a quality product. The cage is CNC. The pulleys look really awesome. When not skipping, I do think they reduce drivetrain friction a bit. The pulleys spin nicely.

I installed this on my Cervelo R3 with all Dura Ace drive train except the cassette which I replaced to CS-6700 12T-30T for this setup only. Installation on the RD-7900 is easy but you need to read well ahead the instructions and understand it thoroughly before proceeding. Pay attention and note the rest position of the original pulley cage when the cage stop screw is released. I fixed the new pulley to the exact same position and orientation.The metals are soft. I did not use the supplied pivot bolt. I reused the original shimano pivot bolt. The color of the gears are red but after I few miles ride, the red color on the tooth are wears off and showing silver, like stainless metal color.

Not high quality - snapped in half when chain skipped a cog.