Clarifying one wee bit of Joe B-Z's excellent comments on half step plus granny gearing on vintage bikes, he said "And the gear charts on the stem are nerdy." In my humble yet extensive cycle touring and regular riding with half step plus granny gearing, a gear chart isn't needed to know your gears. You know exactly how the gears space themselves among the two larger chainrings and that's a half step with no duplicate gears (if you choose your freewheel well as Joe sez). That covers most of your riding (as Joe sez) except for the steep hills. You use the granny chainring gearing for the steep hills, shifting off it when the hill lessens. There's some overlap between the granny chainring on the smallest freewheel cogs and the bottom end of the half step gearing. That's a good thing since you want the granny gear to cover a sizable gear range for your hill climbing. But you don't shift up and down off the granny chainring to find gears to fit amongst the half step gearing.
Peter
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Peter Brueggeman
La Jolla California USA
pbrueggeman(AT)ucsd.edu