I have included below some really good advice on riding tandems courtesy of gtgtandems.com
Don’t be bothered by the long description too much. During our experiences renting tandems we have seen many couples, old, young, kids, people who have not been on a bike for 20 years, and all master the tandem within 10 mins. From there on there is still a lot to be learned in terms of team gelling but the basics are easy enough.
“Tandems are lots of fun, but it takes time to learn how to ride such a large ‘beast’. Start out easy. Don’t go for a century ride on the first time out. Make sure you can get along very well with your stoker/captain. It’s a lot of togetherness and it takes time to become a “team”. Just being married or living together doesn’t mean you will tandem well together in the beginning. The stoker needs to have high trust in the captain. Trust is the important thing two people who ride a tandem share. This is going to take much more communication than on single bikes.
The assumption that the man should be the captain, and the women should be the stoker may or may not be right for you. I know of teams that work better the other way around because of differences in physical build or attitude toward tandeming.
Read, “The Tandem Scoop” by John Schubert. Join a tandem organization, they often organize rides, go to Tandem specific bike rallies. That way you can learn from other Tandem teams. Try and find an experienced tandem team. Both of you (assuming that you have a stoker or captain selected) start by taking a ride as stoker with an experienced captain. A new captain needs to get some experience as a stoker; it will prevent many misunderstanding in the future. The new captain should practice riding the tandem solo; learn the controls and the handling of the bike. Next the new captain with an experienced stoker. Each of these rides should be short, possibly just a few blocks, so that the new person can become comfortable and know what to expect. Lastly, the new captain and new stoker ride together, with the experienced team watching and offering helpful hints.
The first miles of tandem riding may be difficult, as the tandem seems to swerve around the road. Two very experienced riders may take 500 miles to work together as a team. One experienced rider and one less experienced rider will take less time, about 100 miles. Captains may take 50 miles to get used to handling the big bike even without a stoker. Captaining a tandem is very much like riding a loaded touring bike, except the luggage pedals. An experienced or strong rider has to modify their style to accommodate a less experienced partner.
Try to be steady and predictable. Tandems don’t handle like singles; you can’t make sudden last second changes in direction or speed. Bad habits of throwing the bike when standing and climbing will have to be unlearned. Stokers can make the problem much worse (without realizing it) by leaning or attempting to steer. Stokers often lean slightly in an attempt to see around the captain. The stoker should be very quiet (little body movement) on the bike when you first start out until handling is in control and always quiet going downhill. The stoker will have to learn how to get their water bottle or look behind them without leaning the bike. This takes time and practice, so be patient. The stoker should always alert the Captain when going for water. Stokers need to realize that their movements affect bike balance (steering) and the Captain can’t compensate as quickly and as smoothly as for his own movements.
Tandems go like a bat out of hell on downhills. Even coasting, the acceleration on a hill can be quite fast. Work up to speed gradually on the hills. Remember, due to their longer wheelbase, Tandems are more stable at higher speeds than singles. Rim heating can be a problem on severe downhills that’s what the drum brake is for. You can brake aggressively on a Tandem – endos are unlikely due to the stoker’s weight ‘out back’.
Be especially careful when stopped or when coming to an emergency stop or it may be your last tandem ride. When only one foot is down, falls to the other direction are common for new tandem teams (especially if they are not used to clipless pedals or toe clips.
Ride conservatively until you get to know the bike and your stoker’s cycling style. Don’t ride as close to things (cars, barriers, etc.) as you would on a single (this is common for the experienced rider to do) unless you really want to give your stoker a heart attack. Downshift well in advance of hills – they have a large effect on a tandem. Both of you need to coordinate taking the pressure off the pedals, so it can take longer to do. Tandems require more gear shifting than singles due to their mass.
Communicate your needs to each other. Remember that safety requires that decisions about starting, stopping, steering, standing, etc., be communicated. Some teams communicate every shift, I just tell about major changes, i.e. double shifts or shifts into the small chainring. Compromise extends to details such as cadence, since it must be the same for each. Patience, patience, and more patience.
The Captain is responsible for the stoker’s comfort (calling bumps, etc.) and safety (they have little control and can’t see directly to the front anyway). If the captain doesn’t look out for the stoker you’re better off on two singles. Stop when the stoker wants to stop, shift when the stoker w ants to shift, walk when the stoker wants to walk. Take lots of “butt breaks.” Don’t eat anything that give you gas in the middle of a long ride. Make sure the stoker has a good time! Do yourself a favor and never dump the bike with the stoker on it.
When riding as stoker, keep changing your hand positions. Given that you will not be shifting, braking, etc., the tendency is to forget to move your hands around. The result is sore elbows and shoulders, and numb thumbs and fingers. You can even go no-hands without any problems (after advising the Captain of your intent).
Tuck your shoelaces into the tops of your shoes, or tape them down. Tandems eat shoelaces. Own a low vehicle so loading the bike can be done without ladders and hanging out the front window to place the fork into the holder. Make sure that you have tools that fit all the odd sized nuts and bolts that you’ll find on the bigger bike.
Don’t pay attention when the 50th person says, “She’s not pedaling back there!” Try to think of witty (but not snide) comebacks. Enjoy the kids’ reactions to the Tandem – they love them!
The rear tire lasts about half as long as the front. When the rear wears out, shift the front to the rear and put the new one on the front. You always want the best (thickest tread) up front because front flats are not fun at speed.”