Elevating the shift, expanding the capable, the X01 Eagle derailleur features an updated cage architecture, to provide better chain management than ever. The X01 Eagle rear derailleur works with the new 10-52t cassettes and is backwards compatible to also work with 10-50T options.    Features Updated cage provides better chain retention and more precise shifts.. Backwards compatible, works with 10-50t and new 10-52t cassettes.