Hey guys still getting up to speed on all of the changes over the last 15-20 years. My 12yr old son is currently riding a 06 fuel ex8 on 26's with a 2x9 gearset (we pulled the large and put a guard in its place) He is asking me to change him over to a 1x10 setup. Thing is we mostly ride in the Tourne and Dickerson mines and he does go into the granny gear currently. What should i be looking at for gearing if we go this route. The shifters and rear derailer are the easy part. pull of the old replace with newer clutch style. The gearing I do not know and most of what I have found is based on 29ers and 27.5 gearing not even counting we are taking someone without the leg strength of and adult. Any advice would be appreciated.