Is it possible that a dirty/dry QR skewer is making the noise? It doesn't seem possible, but that's the only thing we really changed.

Last night I got all the wheels back on the correct bikes. I took the Mondonico out with the FiR wheel for a fast, aggressive ride last night. 35 miles and the troublesome noise, it didn't appear.... so confused. My ride took me past the LBS, so I stopped in and Kyle (who's been helping me with this bike) pulled the rear wheel and checked it on the truing stand. A couple small adjustments but nothing major.

It appears the FiR wheel has some stress at the spoke nipples, this might be the issue with the spokes loosening.

I plan to purchase a new wheel set over the winter; but I really would love to know that this irksome noise was coming from the loose spokes rubbing or ... could a QR skewer make a rubbing noise???