The PT 60 really is not designed to do rolls with authority. It is a trainer that is really designed to self correct itself out of a turn. As mentioned getting a faster servo will not help any at all. You will need more throw to make it roll, however do not expect much at all, as the PT 60 is a trainer and with all the diheadral in the wing, it really does not like to be up side down. Good Luck, Dave