1st time I've ever had one go bad, it free wheels pedaling forward or reverse. Catches sometimes going forward but that's unacceptable. Good way to crush the family jewels pedaling hard on the top tube. I assume this cannot be repaired with anything less than a new cassette. The rims good. Its on a Schwinn link only a year old. How do I know I'm ordering the right part? Its mind boggling the choices there are. Only 2 things I'm sure of its 26in wh and 7sp cassette. Probably going to need that cassette tool also. Any ideas? Also does the nut[?] that the tool fits into just unscrew normally? RH thread, do I need to hold the cassette steady as that nut comes undone?