I should have made it clearer that we bought both bikes used ... the fit issue would be solved if we had bought a new, custom bike. The Santana was awesome and it's new owners love it.

My captain is 5'10" and rides a 58 cm road bike. So a medium would fit him best, but the mediums in a stock bike are all medium / mediums! It is typically better to have a tandem a little too small than too big for the captain (standover height to spread legs while holding bike at stops, handling). So the small / small still fit him (with a longer stem) but was a much better fit for me. I am 5'1/2" and ride a 40-43 cm road bike.

They do make stock tandems in a large / small ... and there is the custom route which is only slightly more money for a tandem.

We are hoping to test ride quite a few tandems to get a better idea of the differences between steel, aluminum, carbon (Calfee) and titanium (Erikson). It is hard to find a shop that allows direct model comparisons. We'll be at the Midwest Tandem Rally looking at bikes!