Originally Posted by hueyhoolihan

chain noise due to excessive misalignment is not good, as far as i'm concerned, no matter it's provenance. it's a consequence of cassette width. fewer cogs will almost always provide some relief.

it's complicated and so there are too many exceptions on two vs three chainrings or even one chainring. but, in general the fewer chainrings the better. looked at from a larger perspective, a single speed bike with one chainrring and one cog and properly aligned will have no potential for cross-chaining. with every additional cog and additional chainring the potential for problems increases, IMO.

but more to the point, yes, it's expected that not all combinations of chainring/cog can be used. and if they are used there will be some noise.