With the SRAM XX1 Eagle AXS Upgrade Kit you can equip your bike with the innovative SRAM Eagle AXS shift system without replacing parts unnecessarily, and you can choose the crank and cassette most suitable for your bike and/or budget. XX1 AXS rear derailleur The SRAM XX1 Eagle AXS rear derailleur is specifically designed for cross-country use. In this XC design a lot of carbon is used, which not only makes the derailleur lightweight but also very stiff. As a result, the derailleur shifts fast, quietly and smoothly even under heavy load! Eagle AXS shifter The Eagle shifter has an ergonomic design and a Matchmaker X connection to allow you to position the shifter exactly the way you like it. The shifter responds instantly and with high control. On top of this, the shifter’s controls can be set however you want in the SRAM AXS app on your smartphone. In short, with the SRAM XX1 Eagle AXS Upgrade Kit you can get your mountain bike all set for the future! Replace only the parts you need to replace, install the groupset and you’re ready to fly through the forest with even more ease!