cyccommute I don't know how much tandem experience you have, perhaps you have a lot. But let's talk about some stuff that's specific to tandems --

On a Tandem, the stoker is always right. Period. So if your stoker is uncomfortable not being able to straddle your tandem then it's not right for you regardless of what anyone else says. If the stoker isn't happy, then you don't have a tandem team, you have a captain with an empty seat. So the stoker always has to come first.

Bike fit is just as important on a tandem as it is on a single bike. It's vital that the touch points of pedals, bars, and seat be right for both riders. However, the standover portion of bike fit is different on a tandem than a single bike depending on how each team stops and starts. For example, some teams choose to start with both captain and stoker having a foot down, and both have a responsibility for stabilizing the bike at a stop. If that's how you ride, then standover should approximate what you are comfortable with on your single bikes.

However, the vast majority of tandem teams use what has been called "The Proper Method", where the captain straddles the bike, spreads feet wide, and stabilizes the bike in a vertical position so the stoker can climb on and get ready. For these teams, the captain needs more standover room than a single since they have to be able to get their feet wide enough to stabilize the bike without leaning it to the side like you would on a single. The stoker then needs less standover room, because they are never going to be required to put down a foot.

For example, my daughter has ridden on the back of our tandems without a child stoker kit since she was about 4'6". Back then, there were crank shorteners and a stoker stem extension to get the touch points right for her. The seat was as low as it would go, right on the top tube. I would stabilize the bike, and she would step on one pedal and swing her leg around the back of the saddle. We've never had a problem with this process. My wife and I ride the same way -- I stabilize the bike at the beginning, and she climbs on. At the end I stabilize and she climbs off.

The same thing applies, and more so, on our Co-Motion quad. On the quad, I sit right down on the top tube on my right butt cheek with the nose of the saddle coming by my right hip. Then the quad can't go right because the top tube hits my right thigh, and it can't go left because the saddle is against my hip. My weight pushes the bike down for the other 3 riders to climb on and get set. So with all that weight -- heavy bike and lots of riders -- I need lots of standover so I can get my legs wide enough. And the 3 stokers need none.

Many, many teams ride the same way. There have been new captains in this forum that were looking at tandems based on their single bike fit, and people have counseled them that if they're going to use the proper method, then they need a smaller frame than their single bike because they won't be able to spread wide enough to hold the bike vertical. So I guess I would say, these ideas around bike fit for tandems are not some kind of tyranny against smaller folks, as if they're not worthy of having a frame that fits. It's about how you stop and start, and what that means.

Let me say again, if YOUR stoker isn't comfortable, then it's not right for you regardless of anything else. But many teams are comfortable with the stoker not being able to straddle.

Hope this is useful.