Hello, BigMax, welcome to the forum!`

Now I not train the biceps in isolation (curl move)  I only train them in the rowing exercise.   Perhaps they need a litle more stimulation, I think, but I don't worry to not have big, big arms.   I train 3 days a week, but when I had a heavy job, train only two.  I'm 32 years old and my workouts is a four basic mass and strenght gaining compound exercises (bench press, rows, standing press and squats.  Sometimes I add the dead lift; And abdominal and pullover exercies at the end every workout, when I remember   )  For bodybuilding point of view, sometimes I add several exercises after the abdominals, not focus on the weight but in the speed and reps range.  Not for building mass, only to add shape to muscle, but this, at end and two sets .  In this part of the exercises I have little interest in weight moved, only in doing the sets.
Arnold said that the biceps are the fasted muscles to recuperate for the next workout, so he trained them very often.  steroids appart, he has very good genetics in this muscle.  Franco columbus train with him for several years and never had that same peak and size.

If I have to tell you an advice (and I'm not the best man to do it) I recommend that high set intensity one time week that many free drug bodybuilders do (other people in the forum train with that plan since years with good results) or if you want to add several days in a week and can't train heavy and hard two days, train heavy one day, and the other two (or one) do that bodybuilding approach (for shape), withouth maximum stress sets and reps (You know.  Far away from the point of view of says:  "I have to do another rep or I am a shit"   
Even after a years of experience sometimes is hard not to pushing oneself to the hard limit, to often.  Cycling is hard to do, perhaps for the ego, but I think it's good.