Classified hubs are optimised for 1X chainrings with a minimum of 42T for Road & Gravel applications using the 142mm Powershift hub. Minimal 30T for MTB applications using the 148mm Powershift boost hub)
Classified is designed to be flexible, so you can tailor it to your own needs. As a general guide, we suggest you choose a chainring similar to your current big ring for the same size cassette. When in the reduction ratio, the Classified Powershift hub will mutiply your chainring size by 0.67. For a 50T chainring this means you will have the equivalent of a 34T virtual chainring when in the reduction ratio.
Please also observe compatibility with your crank and also check for the required clearances for the chain and chainrings for your frame manufacturer.