This Shimano Oval 96BCD traction chainring is designed for Shimano XTR M9000 and M9020 cranks only. They feature exactly same oval shape as our other oval chainrings. Weight: - 30T (44g), 32T (53g), 34T (63g) Compatibility: - Fits only Shimano XTR M9000 and M9020 cranksets Material: - CNC machined 7075 Txxx Aluminium. - Long-lasting construction! Finish: - Type II anodizing Mounting holes: - 4 x 96mm BCD Asymmetrical design - Original Shimano M7 bolts only Ovality: - Optimized to each size separately. Range: - 10-14% and Timing of 110-116° after TDC (top dead center) All 3 sizes have built-in M7 threaded standoffs to provide the ideal 1X chainline. They improve stock Shimano chainline by 1mm. You can only use Original Shimano M7 bolts with these chainrings (they come with crank). What size should I choose? * 30T Oval chainring has an ovality of 28/32T and is best for someone who uses currently 28 or 30T round ring. * 32T oval ring will suit best someone who uses 31 or 32T chainring currently. While pedaling, you will feel quite similar effort to the one riding round 31T ring (the smallest diameter of the oval is 30T), but you will gain the speed similar to riding 33/34T chainring. * 34T Oval chainring has an ovality of 32/36T and is best for someone who uses currently 33 or 34T round ring. How to mount Absoluteblack oval chainring: There is a small mark (triangle shaped) on the inner circumference of the chainring. This mark Must sit behind the crank arm. It is ideal for 1x 10/11 and Singlespeeds. Oval (elliptical) chainring does not compromise the work of clutch mechanism in rear derailleur. It also does not require a chain tensioner when using in singlespeed application. Riding out of saddle on the uphill will become more pleasant. Ovality of the chainring is 10-14% (dependent on size) and feels perfectly round when riding. These chainrings also help you to recover after knee injuries as pedaling becomes smoother and less exhausting. It is the most advanced oval chainring currently on the market. The most advanced, Patent Pending narrow/wide tooth profile ever produced, guarantee minimum 12 months of excellent chain retention capabilities! We mean it. Always use a new chain with a new chainring.