On 'bents going up very steep hills I have more of a feeling of leaning too far back but have never even lifted a front wheel off the road. The more reclined I have the seat, the more I feel it.
Spent a lot of time down to 3mph on hills on the Sunday of the recent Hilly Hundred - this was on our tandem.
Dumb question: Is it possible to flip a tandem 'bent backwards on a very steep hill? Is this a serious question?