Originally Posted by
jmiked
I can't stand up to pedal because my knee will instantly go out from under me and I'll be on the ground, but as long as I'm sitting down I can get up some impressively steep hills (27 gears help).
In that case, even if you choose to go for a road bike, get one with a triple chainring, maybe a tourer, so you can keep the benefit of MTB low gearing.