Water water water water. Piss all day today and tomorrow. I did my first racing century a few months ago and I looked at all these articles about what you were supposed to do the week ahead of time. I am definitely no pro, just love to ride and ride and somehow got suckered into this one. This is what I learned and did, and I had a great ride. I tapered off my riding the week before. Drank lots and lots of water. Ate more carbs the days before. I learned do whatever you normally do/eat the morning of the ride. I made a huge pot of oatmeal the day before and ate lots of that, cause then I also had some bites before the ride started the next day. So that means if you have tea in the morning, have tea. Don't experiment with anything new on the day of your ride. Just do your routine that works best for you. Have fun, I am envious. I wanna do another century. And eat protein to recover. That was my mistake and I was hungry for an entire week afterwards! Oh an sometimes when you get tired, thinking that you are in the tour de france always helps me!