The S&S couplers are a god send if you want to travel with bike. Let alone if you want to travel with a tandem. I've built up a few singles and tandems (DF and Bent) as well as single and tandem trikes for customers with couplers. And my latest bike is equipped with two couplers, that allows the bike to be packed in a standard bike box if needed. The new bike is a Longbikes, Gulfstream recumbent tandem and has a 106" wheelbase. It is longer then some small cars.
I assemble the frame sections first, the couplers are part of the frame and should one be damaged thats the end of your ride. I always apply a little grease to the threads when assembling the couplers and use the coupling wrench only to tighten the couplers. Using any other tool will mark up the coupler. Had a customer use a pipe wrench and did ugly things to his bike. Make sure the couplers are tight, check them every few days when riding a coupled bike. Ridding with a loose coupler will destroy it.
On my bike I assemble the frame, and install the front wheel. The bike has a two legged kick stand, I flip it down and use it to hold up the bike while I finish assembling it. It also helps when adjusting cables as I can spin the pedals to check gear and brake adjustment.
After the frame is assembled you can assemble the bike just like any other. Make sure your cable quick disconnects are tight and connected to the right cable. I.E. Brake to brake and shifter to shifter.
When packing a coupled bike protect the couplers by wrapping them with bubble wrap or foam (try not to pop the bubbles until after you get back home
) It will protect the couplers as well as the paint. Make sure you take the coupler wrench along with you, don't leave it at home.
"When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought on anything but the ride you are taking." - Arthur Conan Doyle