Most folks familiar with us also know Diane and I have been an avid tandem team since 1998. For many years, having first-hand expertise, we also fitted and built quite a number of tandem bikes for customers, including several very customized bikes. Some of the more common early questions in selecting a tandem are about fitting, and whether the numbers on our singles are transferrable. The super-short answer is a likely yes, but… it’s heavily qualified, and you probably know by now that short answers don’t come easily to me. Having just fielded such a question, here are some thoughts about the basics:
This isn’t true for everyone but, for many of us, fitting a tandem is a bit different from how we like to ride our singles.
Generally the stoker wants to be a little more upright, because she (or he) can be, since she’s tucked out of the wind anyway, and usually wants a better view of passing scenery. Additionally, as long as you’re confident the rear seat-tube will be a good length for her saddle height, knowing exact details of her final fit parameters is rarely critical ahead of time. The rear of the bike is so highly adjustable that you should need little more than confidence that her parameters can be met once you have the actual bike in front of you. Note too that (for most stokers) she never stands flat-footed over the bike, so top-tube clearance is usually a non-issue.
For the captain, on the other hand, it’s a good idea to know most of the details about how his fit will be accomplished. Although his single bike’s dimensions can be transferred, and that’s a great start, beware here too his fit requirements might be slightly different, to accommodate the longer bike and rear-load, as well as possible differences in ride approaches, such as aggressive sport riding on singles versus more relaxed touring on the tandem. Everyone’s preferences and cycling goals of course are different, but these are the things we consider.
Finally, if you haven’t yet much tandeming experience, beware you will both likely spend far less time out of the saddles than you do on your singles, at least initially. When only on our single bikes we tend to thoughtlessly make adjustments, stand, and accommodate comfort needs automatically. Very little happens on a tandem without intention, forethought, and verbal communication, especially at the beginning, so we tend to just sit and pedal until issues become unbearable. Remember too that the captain must be able to very confidently stand over and stabilize the bike, sometimes on un-even terrain, with the stoker mounted. This doesn’t affect how the bike should fit him while pedaling, but it might be a factor in determining its basic size.
We always used to do at least a full fitting for the captain, and sometimes for the stoker. We would certainly confirm basic dimensions for the stoker, but occasionally customers already knew what they wanted, which is great too. We would however insist on finalizing fit details once the bike is built and ready to ride.