I tore my right bicep tendon 95%. I had to get it reattached, it was an unexpected seven hour surgery. Because of that on preachers I never go beyond parallel to the floor with my ROM. I won’t curl anything I can’t do at least eight reps with now. My ortho doc told me he would never do preacher curls, considers it the most dangerous bicep exercise. I love them, so I still do them.
Max on preachers is 125. Recline dumbbell curls are usually work up to the 65s. Standing hammers I go up to the 80s.
My favorite finishing exercise is a stacked drop set at the barbell rack. 8-100, 9-90, 10-80, 11-70, 12-60, 13-50, 14-40, 15-30, 16-20. Afterwards I can’t even flex my biceps without it locking into a cramp. Repaired bicep is right at 19 inches, my left is 18 1/2 inches. I’m 6’2” so I only consider it somewhat respectable.