My relatively new bike was shifting perfectly. All of a sudden, I go out on a ride and the chain starts dropping into a smaller cog by itself. I put it up on a stand and everything looks ok. I notice as i turn the pedals the chain hops at one particular spot. I notice that the master link is kind of catching in the cluster. I notice the side plates are sort of loose and the inside one seems possibly a little bent out. I guess I'd like to know how this happented seemingly out of the blue and is it fixable for tomorrow's ride? could I squeez the side plates with a needle nose safely?