Thanks for the replies. July and Aug are definatley no goes, I have been down to the gap in aug, yuck. I figured late April or very start of may would work. It just means I have to wear/ take cold weather gear as I could be leaving/ returning in a cold snap. I have never gone down to busabash at the gap held in late April as its always to cold and icy here still to ride.
Crap, more " stuff" to pack!