a few days ago I rode as a captain in a tandem. It was very interesting, and I was surprised I managed as I did, as my balance is not so good. Still, since the stoker is some 12 Kg ligher than me, we succeeded to start up more-or-less problem free.
However, now I have some questions. First of all, what do you do about getting on curbs, since you can't bunny-hop? At least I don't think you can. I was thinking that perhaps a well-inflated, superstrong tire (like the Marathon Plus) would obviate to this problem.
The other question is, are there tandem geometries that would make it easier for cyclists of somewhat imperfect balance, to use them? Perhaps if the trail at the front fork was larger? On non-tandem bikes that increases stability once the bike is in motion (although it makes cornering a bit sluggish, a problem I am not concerning myself at the moment). Would a lighter tandem bike help? I imagine that frame material here makes a lot of difference, since there's "more frame" than with regular bikes, so it has more influence on overall weight.
What would be a nice present for a tandem cycling enthusiast? I want to invite her out to dinner, so it should be impressive and thoughtful.