The other day I was checking over my bike, an old Trek 830, trying to figure out where a creaking noise was coming from. I'm a bit of a noob when it comes to mechanical issues, but I've been riding a lot more the last couple of years, using the bike now for commuting, shopping, etc., so I figure it's time to learn to do some maintenance myself. The first thing to I tried to do is see if anything is loose that's not supposed to be loose. One of the things that I notice is that the cage on the front derailleur is loose--I can just rattle it with my hand. I have been having occasional difficulty shifting the front gears--I have to shift a couple of times before the chain actually moves. So I'm thinking this is not right. But the information I've been able to dig up so far is not clear. Is this a) not a big deal, b) repairable/adjustable, or c) it means the derailleur is busted, and should just be replaced?