Thanks, everybody. One thing that's rather disappointing is that the illustration for my Deore (M591?) crankset on Amazon showed an integrated chain guard like what Gnosis and Rapidoyfurioso describe, but I got the crankset without the chain guard -- and haven't had luck finding online sellers of just that part. Maybe it's time to call the LBS and see if they can get me parts w/ numbers from the techdocs EV diagrams? Or try that Soma/OGK set...

-Peter