I'll go along with the suggestions of trying a trike. There are also tandem trikes available as well. My wife & I both have tadpole trikes (2 wheels in front); they're built fairly low and wide, so ithey're about as stable as you can get. Plus, even if you do manage to roll a trike, you're not falling very far; my trike sits fairly high for a tadpole, and the seat height on it's about 18-20". I probably average about 10 mph or so on the trike, but that's not the trike's fault. I'm badly out of shape, but even at that I can do a half mile or so at 18+ mph - the trike's willing, but the flesh is weak!
