the waterproof membrane, 'cept (so far so good) on my Gore-Tex lined BMW Allrounds. i live and ride in vancouver, so the rain is the big challenge...
My feetAs for me, my velcro goes bad first. I'm about to replace the velcro for the third time. I'll probably never wear out my soles first since I usually have a set of walking shoes waiting for me at my destination. I'm curious to hear how others have had their boots fail on them.