SRAM Eagle 90 Ebike Groupset 165mm Brose 36T Clip on Guard Chain XS 1275 10 52t Single Click Shifter Rear Derailleur Primal Wear Brakes: Four piston hydraulic brakes with The flex fabric won Brakes: Four piston hydraulic brakes with electric braking for unparalleled stopping power LED Display: Tracks battery Full Mount Eagle 90 derailleur is the most rebuildable Eagle Transmission derailleur with replaceable B Knuckle Inner Outer Links Bash Guards Bushings Cage and Cage Assembly Shifting under load is a signature of Eagle Transmission and this is made possible on 90 with an XS 1275 T Type cassette that features full X Sync technology and a premium double click T Type Actuation mechanical shifter