I have had this happen. if cost is a concern go to your local hardware stor and pick up some washers for the holes you ripped in your rim. and as for the chain tensioner that flipped around on you, shorten the chain or flip the chain tensioner to the upper part of the frame so that the chain pulls down on it as opposed to pushing down on it. if you cannot reach with that method. you may try pipe straps. they are a metal belt used to hang pvc pipe in your basement. you can buy plastic ones to replace the ones you steal from your house if you do not want to buy an entire roll. you can also take a cutting blade for a dremel and make a few horizontal grooves in you tensioner for some grip on the frame.