A tandem solves the problem of the two cyclists getting irked at each other because the weaker has to struggle and the stronger has to wait. True, there is no inherent reason why two people of the same strength cannot learn to enjoy riding a tandem, although the "Why bother?" question has to be posed. If you are truly equally matched, what you gain for the $$$$ sunk into a tandem are faster descending speeds, a mechanically more complex toy to tinker with, and that peculiarly compelling Bligh-Christian relationship. (And lots of "She's not pedaling!" encouragements.) Not everyone would agree that these are "gains". On the level , two equally strong riders will not be faster on a tandem in most wind conditions than the two of you can be on single bikes together if you practise disciplined drafting, particularly in crosswinds which are murder on a tandem. I'll expect disagreement here, that's OK. I've never stuck a strong(-ish) guy on the back to test it.

If you think that the two of you really are equally strong, you can't gauge it until you try to beat each other, and really mean it. Cruising along in company doesn't count. Find a long hill and both of you ride your single bikes up it as fast as you can. Unless you are unusual for a male-female married couple, you'll probably find that you fit the stereotype of stonger/weaker more closely than you think, and a tandem will do good things for you. (Notice I didn't say that the guy is necessarily the stronger!) On a tandem, you'll climb at closer to the single-bike speed of the slower member....but you'll arrive at the top together and that is often the paradigm-shifting moment that says, "Let's get one!"