Race Face Crank/Chainring Compatibility I have a Race Face Evolve DH crankset which takes 104 BCD chainrings. However, I pulled a 104 BCD chainring off a Shimano Acera Crankset and the rings don't interface properly with the Race Face cranks. The chainring bolts line up, but the shape of the ring below the crank bolts has a different curvature and doesn't mate with the crank spider. 

I'm trying to just buy cheap/durable steel chainrings for my mountain bike and didn't expect this incompatibility.

What chainrings are generally compatible with this crankset? Are sram/truvative rings generally compatible?
I had this problem with a pair of Race Face Cadence cranks (road version).  I think Race Face does this to force you into buying their chain rings.  I am sure there is some "engineering" argument why their rings are more compatible with their cranks, but frankly their rings are only so-so (my opinion).  So far every brand I have tried has this conflict as they use a square profile on the ring/crank interface, not a square with rounded corners.

To get around this simply Dremel or file off the offending material on the chain ring so it fits flush on the cranks.  Then pedal off (or glide downhill in you case) into the sunset with a smile on your face.  I have done this with a some FSA rings and have put 5000 km into them with no ill effects.

Take my anecdotal experience for what it is worth.