Ok, Rohloff didn't go into that much detail on the phone. Only suggested I go down one tooth in the rear. They only offer a 13t 15t 16t and a 17t. They said 13 would lose lots of climbing ability and would also require adjustment to chain line. 15t would be a direct swap. Chainring changes in my situation would be expensive past 38t because I currently have a 104bcd crank and not too many 40t rings out there for that size. It never occurred to me that 2.35 was the minimum and anything higher was still allowed. Thanks for the explanations
Shawn