The SRAM EX1 drivetrain was created for the demands of electric-assist mountain bikes: a wide gear range with bigger jumps between gears, and sturdy components for heavy-duty E-MTB use. The EX1 chain is designed specifically for use with the 8-speed EX1 drivetrain. The robust design is capable of handling the high torque loads of E-MTB, while also running quietly across the gear range.