Mine has a 34t chainring, 22t freewheel, effective low gear of around 12", and it goes up the 10-15% grades around my house just fine, even with payload. As alleng notes, every other IGH (besides Rohloff) will self destruct within a year under these conditions. Nuvinci has been trouble free, and is at least an order of magnitude easier to shift in dicey situations. As for riding slowly, has no one here ever heard of a track stand? Not that I can do one, but I can ride really slowly if I have to. Practice, that's the ticket.
Unless you are running a very small rear wheel that is a gearing of about 20", not 12". Presuming you are running a 26" nominal diameter wheel here is my approximate calculation for your gear inches. You would need to be running a 16" rear wheel for your stated gear inches to be correct.
34 / 22 = 1.55 (Sprockets input ratio) x .5 (internal hub minimum ratio) = .77 x 26" (wheel diameter) = 20".
A 12" gear on the NuVinci with a normal diameter wheel would require a slightly larger rear sprocket than front one, say a 22 front and 24 rear. With a 26" rear wheel this would be 11.9" gearing. High would be about 42" which is about the lowest gear on many road bikes.
For ultra low gearing on an IGH or NuVinci bike you would need to have dual front chain rings if you also want a reasonable high gear available. A limitation of the gear range of IGH units. Even the Rohloff, if set up with a 12" low, would only have a 63" high.
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Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro
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