I wound up going with a 42/19 configuration. With 700 x 38 tires that puts the "normal" (1.0) gear at 60.4 gear inches and the low (.75) at 45.3; the high (1.33) is 80.5 gear inches. My "normal" ride gear on the Boulder is 61.2 and I spend probably 98% of the time in that gear; occasionally I need a lower gear for a steep hill and the low gear I use on my big ring is 45.9 gear inches (I almost never use the small front ring.) The long and short of it is that those gears almost perfect match the two gears that get used on my main rider. I wish I'd done a little cypherin' up front!