Dyna-Sys specific (HG-X) 3x10-speed mountain drivetrain compatibility HollowTech-II (HT2): integrated drive-side spindle with outboard, wide-stance bottom bracket bearings for optimized rigidity and weight reduction Includes HT2 bottom bracket for 68/73mm shells (BB92 and BB30 adapter bearings available separately) CloseStep trail-tuned ratios optimized for Dyna-Sys 10sp cassettes, providing faster shifts with an improved range of gears Carbon-composite reinforced titanium middle chainring and plated outer/inner alloy chainrings for increased durability and reduced weight, with DualSpike pin/ramp technology for accurized shifting performance (middle/outer chainrings mount without nuts due to the blind-hole outer ring interface) Hollow-forged Ultra-Duraluminum crankarm/spider with a 4-arm, 64/104mm BCD chainring interface designed for 50mm chainline 750g with rings and BB @ 175mm