absoluteBLACK Oval 130BCD 5B 39t 2x Chainring Black

. Size (Mass +/-1g): 39T (34g), 53T (110g) . Colour: Black . Compatibility: Shimano Dura-Ace 7900,7800, Ultegra 6700, Shimano 105- 5700, Tiagra 4600, FSA, Rotor 3D & 3D+, S-works and many more. Compatible with Di2 . Important: If you currently use 53/39T round chainrings you have 130BCD cranks. You are looking at correct product. . BOLTS: o For Outer chainring please order Long bolts o Changing Inner chainring to oval only? use original bolts . Material & Finish: cnc machined 7075 Txxx Aluminium. Long-lasting construction, type II anodizing . Ovality: Optimized to each size separately. 39T- 6.5%, 53T - 10.3% ; Timing of 108.5 after TDC (top dead centre). Patent Pending ADVANTAGES OF ABSOLUTE BLACK ROAD OVAL CHAINRINGS: . One of a kind special oval shape that helps you climb easier and faster (Patent Pending) . Over 15% stiffer than Rotor Qrings due to thicker, 5mm construction . Bespoke Absolute Black 6 point ramp and recess shifting design shifts better than any other brand and model of oval chainring . Finest design that provides excellent strength to weight ratio . You will not "feel" the oval shape while pedalling . Your pedalling action will feel smoother . Helps reduce stress on knees and helping your legs remain fresher for longer . You will be able to maintain better cadence while climbing . Reduces possibility of leg cramps . You will reduce chainring/cog shifts by at least 15%