Yesterday, I noticed that during acceleration, there was a consistent noise from my rear wheel. It's almost like a muffled clanging. Reminds me most of the sound that spokes make when they start rubbing together.
Thinking this was the problem, I lubed up the cross over spots on the spokes of the rear wheel, but to no avail.
Okay, second guess. It must be the chain, but after a generous dose of lube, the noise still remains.
The noise only happens when the freewheel is engaged, i.e. the wheel and chain are both spinning. This occurs both when riding, and while under no load in the stand. It even occurs when the wheel is turned backwards, pulling the chain with it.