I have acquired a new SRAM i-Motion 9 internally geared multi-speed hub. As my cargo tricycle is not yet completed I have not been able to try out the hub but I am excited about the new range of gears this offers me as compared to the old Sturmey-Archer 3-speed that I had been planning on using. The SA3 proved a 177% ratio and the i-Motion 9 allows nearly double — 340%.
My daily commuter bicycle is a Schwinn World Sport that I stripped down to a single speed with a rear freewheel. I have a 52t chain ring and a 13t sprocket and 27” wheels (108 gear inches). The cargo tricycle has a 42t chain ring with a 18t sprocket and 26” wheels (61 gear inches). This means my lowest gear on my cargo tricycle will be a comfortable 18 gear inches and I should be able to climb decent hill while hauling a decent load, though obviously at a very, very slow speed