Originally Posted by substructure
AH-HAAAAAAAAAAA!!!!!!
Friday night:
I took my back wheel off and cleaned the cassette really good and the cogs on the rear der. and my chain. Then oiled them nicely. Well the cogs had some thick grit on them and it was actually flaking off. I cleaned the spokes and dabbed a bit of oil between them because there is no clearance and they were kinda squeaking.
This sounds to me as if your problem noise could be a loose cassette. Check the torque on the cassette lockring. It was good to clean the cogs but I don't believe the dirt was causing the noise. Lubricating the cogs may have cushioned the loose cogs.
Al