fascinating and challenging idea there TJohn.
total aside, but if using a rohlof bike, would you ever consider one of those chain cover things made for rohlof setups, a chromoplastic cover that surrounds the chainring, upper and lower chain, and rear cog?
It would seem to me that going over so much dirt road and extremely likely amount of wet, that it would really be an advantage to eliminate or greatly reduce crud from getting all over the drivetrain--so much less maintenance, so much longer life out of stuff.
I always figured these would be a great option for specifically this sort of trip where so much is on dirt and all the ensuing reduction of paste wearing crud on a drivetrain.
can't recall company that makes these, I think its German.
First saw this years ago on cgoab with a couple in South America on rohlof bikes, they loved them and the reduction in cleaning and overall long term advantages with their long trip.