as others have said, its all weather. not too long either. me and a mate were there last weekend, we did (old red), black, orange. lunch. loop on other side of the valley (natural, absolutely cracking, parts more difficult than the black), then black, orange. home.
one of the best days out for a while (well, save taking a tandem round GT red).
black, imo, is more of a head **** then anything else. there is one step which i just can’t get my head around, near the start, but the rest is fine. i prefer to follow someone down, as i’d be a bit mroe tentative if i was at the front (having said this, i’ve not done the black all that many times). we were both on 130mm HTs with nothing more than helmets and gloves.
take it easy and look at the difficult bits before you go down them, and you’ll be fine.