Wolf Tooth Shimano 110 Asymmetric BCD Chainring - 42t 110 Asymmetric BCD 4-Bolt Drop-Stop ST For Shimano GRX Cranks BLKWolf Tooth Shimano 110 Asymmetric BCD Chainring 42t 110 Asymmetric BCD 4 Bolt Drop Stop ST For Shimano GRX Cranks Black. These chainrings are for Shimano GRX cranks. They feature Wolf Tooths patented Drop Stop design for the best wear life chain retention and mud clearance. Drop Stop ST is specifically for the Shimano 12 speed Hyperglide+ chain which is used by GRX 12 speed. Compatible with Shimano GRX cranksets including RX600 and RX810 Drop Stop ST