Would anyone like to chip in with transmission suggestions for Innertuba? The brief is a recumbent trike (ICE, 18" -355 rear wheel IIRC) towing a heavy (say 40 kg) trailer on multi-month tours including a planned tour across Canada, with a rider who wants to spend as little time on maintenance as possible. Very low gears (single digit inches ideally) would be good for hills, but also a highish top gear (say 80"+ at least) would be useful for making good progress where conditions allow...