Rotor Bike Components DIRECT MOUNT Round Chainring 50/34 ALDHUThe Direct Mount is CNCd from a block of 7075 aluminum to save more than 30 g over a standard chainring combo which, together with ALDHU crank arms, becomes ROTORs lightest crankset ever. The ALDHU 3D's innovative modular structure makes each component individually available to accommodate the current spectrum of riders and bike standards. Precision machined chainrings to shed grams from your crankset Lightweight, single piece construction reduces