Originally Posted by
sdimattia
Thanks! This gives me an excellent idea of what to look for in gearing. I recently climbed an 11% 0.4mile hill on my road bike with 29 GI naked (as in just me on the bike, with clothes). Had to stop once but didn't have to get off. The gearing I'm looking at now ranges from 115-20 GI with a GRX 2x drivetrain, 105 brifters and TRP brakes. I'd love to get it down to 99-17 GI with a 36/26t crankset but finding the corresponding front mech is a bit of a pain.
I have three touring bikes, light, medium and heavy.
Light touring, the Lynskey (photos previously posted in post 31) gearing ranges from 20.7 to 115.5 gear inches with 700c 37mm wide tires.
Medium touring, 19.3 to 107.7 gear inches with 26 inch tires, 50mm wide.
Heavy touring (bike in last photo in post 12 above) range from 16.2 to 85.2 gear inches with 26 inch 57mm wide tires. This lowest gear gives me 3.5 mph with a cadence of 72.
I think a good range for what you are planning is around 20 to a bit over over 100 gear inches. Lower is nice but on paved roads you will probably not need it much lower than 20 inches.
I pushed my bike up this 13 percent grade hill (photo below), lower gearing would not have helped because if I was going fast enough that I could have maintained directional stability, my heart rate monitor would have told me to stop. Pushing allowed me to maintain a sustainable speed up the hill.
My point is that having a gear low enough for any hill you ever will encounter is impractical, I have seen 20 plus percent grade hills. You have to draw the line somewhere.