You cannot go smaller than a 38 tooth middle ring on 130mm bcd. I am running an Ultegra tripple with a stainless 24 inner and a Sugino 38-48. Shifting up to the 38 is a bit slower compared to a properly mated Shimano set up, but not at all important for touring. I am using Tiagra brifters, and it takes a little more than a single sweep of the shift lever.