Fuji Touring bike with Shimano Deore rear derailleur.
I was right hooked by a car a couple of months ago. I thought everything had been repaired, but recently I've noticed something. The pulley wheels on my rear derailleur aren't in line with the rest of the derailleur any more; there's a slight offset between them. So the chain doesn't stay in a flat plane anymore - instead it flares out (very slightly) as it passes through the pulleys. There doesn't seem to be a bend in the cage that holds the pulleys. Instead, it seems as if the alignment between the cage and the rest of the derailleur has been screwed up. I haven't really noticed any effect when I'm riding, which is why it took me so long to notice it. However, it does affect back-pedaling. The chain seems to get caught up in the pulleys a little bit. It's a bit of a hassle, but not an earth-shaking problem.
Can this be repaired? I thought before trying to bend it I'd check in here. Maybe I'd get a "happens all the time, it's an easy fix" piece of advice.
If it can't be easily repaired, can it be replaced (short of replacing the entire derailleur?) I've looked around at parts websites, and although I've seen pulley wheels for sale, I haven't seen the cage. So I'm guessing that it is only available as part of a complete derailleur.
A new Deore isn't going to wreck my retirement fund, but I'd like to repair it if possible because a) I hate replacing a perfectly good part as a matter of principle, and b) at some point I'd like to have the money I'm saving on gas not have to be plowed back into purchases for the bike. So far the benefits of commuting by bicycle have been primarily cardiovascular rather than financial.