Just another instance of the CS nut being not torqued at the factory. After 6200 miles I replaced chain and spockets tonight. After unfolding the fold down safety washer I got my buddy (wife) to step on the brake and when I put the socket on the nut it was completely free! I'm convinced it did not loosen up along the way but was assembled that way. The fold down washer was properly secure. BTW, I did not Locktite the nut during reassembling. My reason is that I plan to change my sprocket fairly often between 14T and 15T. So I'll see first hand if there's any loosening going on.