Thanks for all your encouragement.

I have never had the chance to attempt a 5+ mile 8.5% hill before and I am thinking that that is the physical challenge that I want to shoot for - a century can wait for another time.

I know that I can handle 10% hills in the 300'-400' range with my current 12-25 cassette. Whether this is low enough to do at the 60 mile point is another question. I guess I will find out on Saturday!