Rootman asks
If you could get an internally geared crank with the proper ratio to get the low gears and then switch to a higher gear in the front for the flats and down hills. Besides MORE added weight and expense would it even work?
given 10 of the 14 gears in the hub are already reduction gears, the combination is
stick to the external gear ratio guidelines , and pick the overdrive crank,
that will be engaged to get you a gear you can turn slowly as you blast down the mountainsides
example 38t x 1.6 (schlumpf speed drive) makes a 60.8t chainring size..