Control Tech Rage/Rage OS D Crankset Chainring Review Posted on August 16, 2018November 9, 2018 By ArchSeaLionPosted in Drivetrain ComponentsTagged Control Tech, Cycling, Outdoor Recreation, Parts & Components, Sports & Outdoors Chainrings:24/27/28/29/40/42/44T BCD:104/64mm Material:AL7075 CNC Crankset Chainring for Rage D/Rage OS D, Material:AL7075 CNC BCD:104/64mm, chainrings:24/27/28/29/40/42/44T.