Ok, so here's my problem: using a barbell, I can only bench 155 pounds, but using dumbbells, 110 pound dumbbells are a breeze. I don't get it, anything over 155 and I literally can't get the bar back off my chest up. It's nothing to do with my form, as I can feel the muscle working doing both exercises. I don't have any ideas or theories on why this is. You guys have any?