Counting cogs is hard.
If you are running 9sp cassettes friction works. 8 is better but I road S America from bottom to top on 9sp friction. Toss a bar-con or a thumbie on your handlebars and go.
As for gears, running medium fat slicks, off road, and with four bags 22x32 was my max. Anymore granny and walking was better. On tar 22x36 worked.
Edit: The only rear tire that ever survived a 6+week long tour was a marathon+ 1.75x26. Once back home and gear stripped wow did i notice how much of a boat anchor it was.
Last edited by escii_35; 09-02-16 at 03:48 PM.