Okay I'm confused.. this sounds like a chainline problem to me.. like the same exact problem a friend of mine had. I bow to the superior knowledge of these guys but I'll offer you this, he bought a BB with a shorter length that split the difference placing his chain ring in the center of his cassette via straightline, he runs no bashguard no chain guard, no chain guide, no FD 1x7 on a dually mtb.. I've yet to see him drop a chain since the switch.