On my central coast tour, I carried about 50 pounds. I did not like the way of bike feels with that much weight. Felt really tipsy. did fairly well at climbing. I was surprised, since I had done little previous riding with weight.
I always suspected the most vunerable part of the bike under weight is wheels ...Particularily the spokes.. When my LBS found out my touring bike had lots of spokes breaking( luckily prior to my tour) my great bike wrench upgraded my spokes at a great deal. Was good of him to do that, because normally his policy is, is just to swap out for new wheels.