It's freaking me out! I read a whole Facebook thread about cassettes and hills, and false flats and how hard it is.I've heard about the 10-11% grade hill climb.
I guess the good thing is I ride with a compact 11/28, which was suggested in one of those threads, I've also been riding hills with an 18-21% grade. It's going to be a long ride for sure, but I think that is how it's going to be for the majority of us on race day!!
YOU'RE READY!!!!! It will be so beautiful, your legs will be tapered and you won't feel those climbs like you do in training. It will be a tough day - it should be, it's Ironman!!!! BUT, you're ready!