My last few racks of baby back ribs have ended up much tougher than I would like (I like the meat to fall off the bone). I have been using the 2-2-1 method without success. My meat thermometor says the ribs reach the 172 degree mark much faster than I would think. I have been pulling the ribs out when they reach 172. Do I need to leave them in longer to get them more tender, or will that just make them even tougher? Do I need to cut back on how much dry rub I am using? (I put a coating of Mustard on after I remove the membrane.) Do I need to switch to pork spare ribs to get them tender? Any help is very much appreciated.