
Originally Posted by
kajero
PS: Just for laughs I will tell you the wonderful solution my SO came up with. I can get off the bike and change the sprocket when I need to!
That's how they did it before ol' Tullio invented the derailleur. My step-grandfather used to tell about touring the Alps that way. 
Hope you find a better solution...
Speed comes from what you put behind you. - Judi Ketteler