Old ground maybe…..I’m thinking of going for a double and maybe a bash guard. If I can come by some XTR M970 cranks, can I just fit an SLX 36T middle ring, as both 104mm BCD? Potential pitfall warnings and advise from those who’ve been there before would be appreciated! Are the M970 cranks themselves much lighter than XT or even the SLX triple arms (without the steel axle and pedal inserts of the double SLX chainset)?