These chainrings are for Shimano direct mount cranks. The Wolf Tooth chainrings feature our patented Drop-Stop® design for the best wear life, chain retention and mud clearance. COMPATIBILITY Shimano XTR M9100, XT M8100, SLX M7100, and Deore M6100 series 12 speed cranksets. Super boost cranksets -models M8120, M8130, M7120 and M7130 - use the Boost chainring. These Super Boost cranksets have a longer spindle and do not use the Super Boost chainring. These cranks and ring should ONLY be used on bikes with Super Boost rear hub spacing (157mm) Boost cranksets - models M9100, M8100, M7100, MT610 - will use a Boost ring with Boost rear hub spacing (148mm) and a Super Boost ring with Super Boost rear hub spacing (157mm). Use Drop-Stop ST with Shimano 12-speed Hyperglide and 12spd KMC chains. POWERTRAC ELLIPTICAL More power? Check. Better traction? Definitely. Less shifting? Yup. Funky uneven pedal stroke? Not with Wolf Tooth’s PowerTrac Elliptical™ (PTE) chainrings. Our proprietary design means a slightly less ovalized ring (10%) with less aggressive timing (112°) than competitors’ versions; any change to your pedal stroke is unnoticeable for most riders, but they still provide the power and traction benefits inherent to oval chainrings. It’s like having two chainrings in one! With PowerTrac Elliptical rings, the larger-diameter section of the ring engages with the chain at the optimal point on the downstroke, or “Power Zone” – between 1-5 and 7-11 on a clock face – to take advantage of your body’s natural biomechanical power. For example, during this section a PTE 34t ring is equivalent to a 36t round ring. Similarly, in the “Recovery Zone” (11-1 and 5-7) the smaller section on the PTE ring engages, maximizing efficiency in the weakest part of the pedal stroke; here the PTE 34t ring is equivalent to a 32t round ring. Additionally, the above provides a smoother, more efficient pedal rotation, which means better traction. Steadier torque on the rear wheel means less spinning out in the “Power Zone,” while pedaling is easier during the “Recovery Zone,” so you maintain momentum. DROP-STOP TECHNOLOGY Wolf Tooth’s patented Drop-Stop® wide/narrow tooth profile delivers ultimate chain retention and mud shedding ability. RECOMMENDATIONS We recommend the use of a clutch style rear derailleur for the best chain security. For a longer lasting and more durable option, check out the CAMO System that offers stainless steel chainrings.