Hi there. I just happened to notice on the internal gear calculator on Sheldon Brown's webpage, and the fact that you can enter up to three different chainring values! That seemed a little crazy, but I entered some values, and holy cow! Combining a 46/36/26 crankset with an 18 tooth cog on the Shimano Nexus 8-speed hub would give a range of 22.8 to 101 gear inches on a bike with 26-inch wheels. Thats 443%! That's roughly comparable to using the same crankset with a Megarange freewheel or cassette, and has obvious benefits in a touring application.
Now, unless you're getting really high-zoot derailers and cogs, it's probably more cost effective to go with the derailer gearing option. The use of integrated brake/shift levers could easily push the cost the other way, however, and besides I'm curious: is this even doable? It would certainly require some tinkering - at the very least a chain tensioner to take up slack in the chain, and perhaps some fiddling to get the chainline straight in the middle chainring, but... man, what a unique bicycle that would be!
Does anyone think this would work? Have you done this? Do you know someone who has? Could you use a chain tensioner in that way? Am I crazy?
Anyway, let me know what y'all think. Cheers!