Ah, more data. Rohloff does have a few methods of establishing the reaction force arm/washer that other IGHs don't have. But I did note the possibility of a chain tensioner and that instruction sheet recommends one when the drop out slots are what you have. So I fail to see how modding the frame is the easiest and most simple way to use the Speedhub. I think your decision to move on from this frame is smart given your requirements. Andy