Originally Posted by
ZHVelo
But that does not explain that some gears are more quiet and that moving the position of the derailleur also seems to impact noise levels. Nor that after using lube there is basically silence for 20 minutes, but only 20 minutes.
Why doesn't it explain why some gears are more quiet? Different size bells, drums, horns, produce different amounts of sound, why would a different size cog?
You are going to have to drive train noise with a chain. If you are sitting there in the quiet of your home with your bike in the stand, you are going to absolutely hear every roller slap the tooth it's engaging and the links shift position on the tooth as they free themselves from the cog.
Even on the road you might hear this when ambient noise is low. You friends riding next to you may or may not hear it. Some sounds only travel far enough to annoy the rider.
But I've no idea if I'm talking about the same sounds as you. Perhaps you do have something odd, but 20 minutes after lubing you hear the sounds again makes me think you are ignoring the facts of life with a chain and cog.
Not that some aren't pretty quiet, but none are perfect when ambient sound is low enough.