You can use BikeCalc.com to help sort out these "what if" decisions. Just enter in your existing configuration then use that to compare different chainring / rear cog gearing scenarios.
Much appreciated for this suggestion!
I've broken this down into 3 scenarios, where the speed of my average hill climb is around 8 mph and I typically ride around 12 mph on relatively flat path and might top out around 18 mph when cruising down hills. No idea what my cadence is, so I kept the default at 90. Goal is to gear my wife's bike to match my skill level as I will be riding a non-powered bike ahead of her on the trails.
I find it interesting that the recommended chain ring sizes are 29T, 38T, 39T respectively for these 3 speed targets:
So my options are to choose between 36T and 42T for the Lekkie, I'm leaning toward the 36T being reasonable with the following fixed at 36T chainring:
It looks like the bike will top out at 17.83MPH with the 36T chain ring, but that seems like a decent compromise to ensure optimal hill climbing efficiency, correct?
*** UPDATE
Another assumption with these calculations is the cadence is fixed at 90, so I'm thinking that the BBS can probably handle a higher cadence to help the bike reach the 20mph max speed limit anyway.