Chainring Wolf Tooth Shimano E-Bike Direct Mount Drop-Stop B 32TChainring Wolf Tooth Shimano E Bike Direct Mount Drop Stop B 32T Wolf Tooth Direct Mount Chainrings for Shimano E Bike Motors have a 55mm chainline and are compatible with all Boost and Super Boost bikes that use the Shimano EP8, E8000, and E7000 e bike motor splines. The Drop Stop B tooth profile is compatible with almost all 9 , 10 , 11 , and 12 speed chains the only exception is Shimano Hyperglide+. Compatibility Compatible with all Boost and Super