Aluminum 20T gear pulley on primary layshaft drives back belt. CNC-machined from premium lightweight Swiss 7075 T6 aluminum, hardcoated for extra durability and long lifespan and possesses been strategically lightened. Rotating mass is paid down with no need to lose power or durability. Belt pulley is offered with braking system disk adapter and includes factory-pressed pins (non-replaceable). Factory pre-assembled.