Have a new to me xplorer it’s chain drive. I tightened the chain cause it was loose when I got it. Now I hadn’t really risen it other than a quick test drive before I bought it. Did a bunch of maintenance including tighten chain. Yesterday first real ride I heard a popping noise coming somewhere from rear but not exactly sure what it could be? I don’t think chain is to tight it’s within the specs it’s supposed to be. Could it be to tight? Could it be chain itself or sprockets or something else in the rear end ?