Soap and water.
Ours has made noise occassionaly. It seems to come and go. Its been quiet for a good while now (knock wood.) The Web cyclerly people say that dirt can make it a bit noisy. IIRC correctly they recommended mild soap and water.
Also, I don't think it's suppossed to "press against the rim" Co-Motion says it should run from Zero to .5mm from the outer wall of the sprocket. Zero would be against the wall, but again I'm not sure it should be "pressing" into it. So you might check the belt alignment.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.