I have been riding at 48x16. I just did 115 miles two weeks ago. Took me 12 hours with stops and a huge headwind. I have rode two training rides in the last week at 40 miles each. Since this has been without any packs I know I will have to drop down to a 42 ring fully loaded. I like the idea of two cogs for possible hard climbs and spinning flat distances. Great idea. But I can't go with a free wheel that would be cheating.