Sprocket/Cassette Help

[90chris]

Hey everyone, so I'm having some problems with my chain on the bike side, this is my first MB and I don't really know too much about them. So ill be riding it and everything will be fine and then out of nowhere my chain will slip gears ( as it has a set of gears)and then it'll be to tight and Ill have to reset it and It's getting old doing this over and over. So I'm thinking ( and plz correct me if I'm wrong, or if you have any input) that the chain might need to be replaced and if not that then I need to get a new cassette right? Cuz I can see tht the teeth are worn. Also im able to switch the gear set out to a single set sprocket as i have no need for the set of gears, Or do I have to replace it with a new set? Thanks for any help- Chris

 

[Sidewinder Jerry]

Does he have Vbrake mounts or just a single hole cross member? Pics show us nuttin.

He hasn't posted any pictures of the forks or rear seat stays.