Premium Campagnolo compatible Oval chainrings designed for Super Record, Record and Chorus 4-bolt 145/112bcd cranks. They work perfectly with 11 & 12spd drivetrains thanks to our ingenious design. Incredibly stiff and light. Super-fast shifting thanks to our patented shifting ramp design. Same brilliant oval design like in the rest of the collection. Use original bolts. It is the most Premium oval chainring on the market with scientifically proven performance gains. ADVANTAGES OF OUR SPECIAL CAMPAGNOLO COMPATIBLE OVAL CHAINRINGS: - Finest design to provide excellent weight-to-strength ratio - One of a kind special oval shape (Patent Pending) - Superb quality and great look. - You will ride faster using ovals. - You will not "feel" the oval shape at all - Reduces stress on knees - We mastered our oval chainrings to perfection, so you can get best possible advantage from the oval/elliptical shape. - Size (Mass +/-1g): 53T (90g), 39T--(42g) - Compatibility: Campagnolo Super Record, Record, Chorus 4-bolt 145/112bcd for 11 and 12spd versions. - CNC machined 7075 Txxx Aluminum. Long-lasting construction - Ovality: Optimized to each size separately. 39T- 10.4%, 53T--10-11.2% - Timing of 108 -110.5 after TDC (top dead center)--ideal for road climbing