Triceps were excellent and the forearms were just as good - it didn't matter too much about the biceps because he knew how to conceal them and also bring them out in certain poses - he worked his weaknesses to his advantage - it also goes to show how little biceps really matter in the overall scheme of things.
Ronnie had excellent biceps, but personally I think his triceps lacked in comparison, especially in the side tricep pose and it really showed.