I took my rear wheel off today to do some thorough cleaning. (There was so much compacted dirt in the derailleur pulleys, it was unreal!) I got the wheel back on just fine, but now the fender is rubbing against it ever so slightly. I don't know what I did wrong to cause this problem in the first place, and I can't seem to fix it. Is there something I'm missing? Thanks!

You've probably tweaked the fender stays on one side. Press slowly but firmly on the stays in the opposite direction, until they bend back to where they should be.

ECB

Thanks, ECB-- that was exactly the problem and I figured it out shortly after posting this! I'm glad it was nothing serious. I did find a mysterious "extra" washer after I put the wheel back on (oops).