Well, last night before I went to the track I did the usual chain tightenting ordeal. ( The chain I have is a gold Renthal R1 (I think) and it is a pile...It loosens after every ride no matter how tight it was previously.) So today when I was doing my routine maintinance, I saw that all the teeth on my rear sprocket were broken! The teeth were fine the night before. It is a Renthal 50t sprocket as well. How does that happen. The only way I know how to adjust my chain is by the axel markers (I have aftermarket Pro Circuit ones) I even try and count the threads on the adjusters when I do it too. So my questions are: 1. Do I have to get a whole new chain/sprocket combo or can I just replace the rear sprocket? 2. Whats another good brand of "drive components" 3. Lastly, am I just an idiot and doing something majorly wrong? Please, any advice will be greatly appreciated. Thanks!