I have Avon Venom Xs and I run 42-43 in the front and 45 in the back. I get about 15,000 miles on them. No cupping, no other problems. However, the ride is very firm. Also, with that said, the bike handles perfectly.
You will get a lot of 41-41 from people. I don't where that formula came from and it's safe at that. However, I can't believe that one size fits all in this.