Premium Oval Road 39T, Shimano 9100/8000 - Black

- Compatibility: Shimano Dura-Ace 9100, R9120, R9150 & R9170 Di2 and Ultegra 8000, R8020, R8050 & 8070 Di2, 105- R7000, R7020, R7070. They can also retrofit all 9000 and 6800 series cranks but use bolt covers for best appearance. 10 / 11 / 12sp compatible\n- For outer chainring please order "long bolts" from us OR bolt covers. Changing inner chainring to oval only? use original bolts\n- Inner and outer oval chainrings are optimized with smooth shifting in mind\n- Features smooth angled surfaces, (6) up-shifting ramps (outer ring), and (12) down-shifting points (outer ring)\n- Oval rings help the rider to spin smoother and more efficiently\n- Example: 32t is equivalent to 30t at dead spot and 34t at the power zone\n- Works with 2x chainring systems and does not require any modification to the front derailleur for use\n- Designed in UK, manufactured in Poland\n- Third party online retailers must be preapproved by manufacturer