Replacement compatability for Shimano Mountain LX Chainring and or Crankset I need to replace Shimano Mountain LX Biopace Chainrings with 48/38/28 110 bcd and am having difficulty finding replacement chainrings, particularly the center chainring 38T. It appears Mountain LX is rare and I would like to know what other Shimano (Deore) or other chainrings or complete cranksets are compatible.
You cannot replace Biopace unless you find some antiques. Biopace ended 20 years ago.

Other chainrings are all compatible if the BCD is correct. The only issue is the ramps or pins that are meant to improve shifting performance. The manufacturer will always tell you to match everything up exactly but that is their sales pitch. Realistically having something ramped on the middle ring is a good idea and maybe on the big ring too. Ramps on a granny (smallest) ring don't make any difference. If you are really worried about compatibility get something similar (XT, STX, Deore...) with ramps that is from Shimano and you will be just fine.

Any square taper crankset which allows clearance for the frame and similar chainline will work fine. Actually buying a complete crankset with all the rings included is a lot cheaper than buying individual rings. The extreme example is a low end shimano riveted crankset for less than $40 vs the typical budget of $1/tooth for chainrings.