I own an older model Novara Aspen and it recently began to have problems with coasting and freewheeling. Now it's to the point where it is unrideable because the pedals spin with the tire making it impossible to ride. And after coasting, slack will build up in the chain so I have to pedal around a few times before all the slack loosens and it catches on. I've removed the rear tire and tried loosening the hub but it hasn't made a difference. I believe I've discovered the problem (the entire cluster of gears on the rear tire will not move in either direction) but I do not know how I would go about fixing that? Also, (not as crucial) the chain will wiggle back and forth while coasting and it gets rather annoying. Is this just a matter of getting rid of the play in the tire?