And tandems are really great for two strong riders looking for a new challenge. Tandems really fly on flats, rolling terrain and downhills. Climbing is considered to be more difficult, but a tandem team with lots of practice can climb amazingly well. Tandems are good for touring because the extra weight is much less noticeable than on a single, but be aware that there is HALF the luggage space. Of course everyone knows that when touring you will FILL your bags, no matter what the size, so this could be an advanatge.
Communication is the absolute key to riding a tandem.
It has been said many times that a tandem can make or break a relationship. Ideally the front part of the bike should fit the captain. Tandems take a little extra handling effort and a smaller bike may be easier to handle. One thing to be aware of is that the stokers handlebars attach to the captains seat post, so the captains seat can not go all the way down. If the bike is marginally large for the captain, this could present problems.