Hello, my drivetrain setup is Sugino 75 cranks w/ BB and Chainring, Phil Wood high flange hub w/ Dura Ace cog and Izumi V "Super Toughness" chain.

My drivetrain ran smoothly and quietly before I upgraded my cog. I had an EighthInch 3/32 cog, but now that I have the DA cog, it's significantly louder. The chain has no stretch, chainring is in good condition, so what's up with the cog? I got it used but it's in good shape