I curl a 60 ibs bar in my last set for 10 reps. I tried 70, But my wrists don't like the straight Bar that Bally's has with that weight. The 60 ibs one is a easy bar which works great. I haven't tried the 80 ib bar yet. Maybe next weeek I'll throw it up and see how many reps I can go.
I dont think i've ever maxed out on curls, but if I had a guess, Id say about 135-145 standing with a straight bar. And by curl i mean back straight, elbows immobile, all bicep. None of that swinging, or bringing the elbow back shit that you see most people doing.