Hello all I went out for a ride the other day and My back wheel all of a sudden started rocking side to side which is also causing my tyre to rub on my frame somewhere, Everything is Tight I double checked that and yet it still Moved. I have taken the wheel off to see if the lock ring was loose, But it wasn't. I then noticed that when I pull the side where the lock ring is, it moves in and out like half an inch. Has anyone had this same problem, or similar. If so how can i sort it out as it slightly worried me. All help will be appreciated. Danny.