Ohh I am game for September 5th I just did 30 mile's today. My longest to date is 31 but I still felt good after the 30 today except for my but, My saddle is good for the first 25 or so but after that it gets uncomfortable. Sheldon brown has something for that shifting when your going up hill. something about your cable where it goes under the BB, If it is at all tight, flex in your frame can cause it to shift I think he recomended lubing it with something but I dont remember what. I will look and re post.

This is the link https://www.sheldonbrown.com/autoshift.html