I guess I'll be the first to post my results. I incorporate chin-ups in all of my back routines. I weigh in at 240lbs and I can do 46 reps ( without rest, palms facing away from me, chin over bar and alittle farther than shoulder length). So when I strapped on 100lbs in a back pak(palms facing me, closer than shoulder width, chin over bar) I was able to complete 22 reps....any contenders