The e*thirteen Gen 4 TRS Race Carbon Cranks have a reduced Q-factor and overall profile and utilize a special compression molding technique and additional 3K carbon in impact areas to create a light weight carbon crank system which tests significantly stronger and more impact resistant. Features compression molded carbon fiber crankarms and a 73mm aluminum P3 Connect spindle for superior durability and weight savingsSpindle is located on the non-drive side of the crank for easier chainguide setup and drivetrain maintenanceCrank and spindle features Quick Connect lockring and Adaptive Preload Adjuster for easy chainring installationThe adjustable chainline accommodates non-Boost (142mm) Boost (148mm) and Super Boost (157mm)Compatible with e*thirteen's SL Guiderings (28-38t options for non-Boost and Boost frames) and UL Guiderings (30-42t options for Super Boost frames)Compatible with the following bottom bracket standards: 68/73mm threaded BSA PF30 BB30 BB92