I have a Tacx neo2 and I replaced the 11 speed cassette with a Zwift COG2. (all the freehub replacement malarky!). What I noticed is that the COG is noisier than a normal cassette. Its adjusted correctly, but it makes far more noise. Its like the plastic resonates. Its not as loud as my old turbo trainer, but still bugs me. Has anyone else noticed this?
Some people report quieter operation by replacing it with a third party single speed conversion kit.
I have the same setup, and it’s pretty quiet (at least when properly lubed). Are you sure it’s fully tightened down on the freehub and axle? And that the dial is adjusted so that the chain centered on the Cog? And that your rear derailleur is in the correct gear? (Sometimes I shift the bike gear in error, and then the Cog makes a horrible noise.)
I tried that. It was horrific. Had to use a chain chain tensioner which rattled like hell.
The other potential factor here is the chain - its condition and whether the model of chain is a good match for the Cog’s tooth profile.
But yes many people have replaced the Cog with a third party conversion kit when using the Zwift Ride and reported it was quieter. Of course a chain tensioner of some kind is necessary though that can be a derailleur.
Make sure the Cog is assembled correctly. Mine from the factory was not.