XR stands for EXTRA RAD. Marin turned the Rifty E up another notch with this one - RockShox Lyrik Ultimate fork and Super Deluxe Ultimate Shock, Vee Tire Co rubber, Shimano XT drivetrain, next-gen Shimano EP801 motor, SRAM Code 4-piston brakes. And the cherry on top? SRAM AXS wireless shifting and a wireless RockShox Reverb dropper post. Our highest spec, highest tech Rifty E ever.