I don’t know what the point is. I guess he was asking if a RD single front could get close to an IGH in terms of range. In my case I have went as low as 16 GI and still kept the bike upright but I thought it would be less work to push at that point. 18 or 20 GI will let almost anyone climb anything. As far as top end gears I don’t think as most do that the limit is strength and frontal area. I enjoy my tall gears when I’m getting a little help from gravity or the wind and I don’t feel like spinning. Anything much over 100 GI trying to spin it up and build lots of watts is going to be tough for most. But I don’t go full out spin or mashing when I’m in them. Sometimes a slow cadence in a high gear works ok for me. I couldn’t get the full range I would like from a single chain ring where I live and ride. If I was in FLa. I could easily get by with a single in front.