Hardtail vs. Full Suspension.

A hardtail (HT) will offer less weight and ease of maintenance. Though it is pretty rare, problems occurring with a rear shock could cause some grief if they did happen overseas. Rear racks and panniers will be more compatible with a hardtail. However, for longer rides or rougher terrain a hardtail may take its toll, exacting more energy from your body over time than a dual suspension bike. One way to mitigate this is to use a suspension seatpost on your hardtail.

My 2013 Santa Cruz Chameleon HT that I will be touring with next.

A dual suspension/full suspension (FS) bike will offer you greater comfort, control, and range of terrain to ride. You will need to bring a shock pump along, because boxing or bagging your bike for flight typically requires depressurizing the shock. However, it is likely you will be running an air sprung fork up front so a shock pump will be necessary anyway (I’m assuming no one would be running a coil shock on this type of bike).

If you do run into a serious problem with your shock you are probably quite out of luck. Although there are a number of local bikes shops around the world that can service a fork or shock, more serious problems require sending the part back to the manufacturer which would put you out of the game for weeks.

If you are planning on mounting a rear rack on your full susser, be sure it is compatible. When your shock compresses and your rear triangle begins to move you may find the rack (or its baggage) striking your seatpost or saddle.

My 2012 Yeti SB95 with 5" of travel in the rear suspension. The Thule Pack 'n Pedal sport rack I used in the rear had no real problems with clearance even though I was using ordinary bags lashed to the rack to test its practicality.

The bottom line: First consider all you want to do with the bike on your trip. If this includes some aggressive riding, rough terrain, or long and/or many days in the saddle, I would opt for a full suspension frame. If not, or if you enjoy all of the above with a stiff back end (on your bike or your body), go with a hardtail. 

If you decide on a full susser, determine if a rear rack will be compatible with your frame or if you even need one (I was able to mount a Thule Pack ‘n Pedal Sport rack onto my Yeti-SB55 without issues when the saddle was at proper height for flat and uphill riding and my load was positioned properly).

As for maintenance issues on a rear shock, the same concern really goes for your fork, so just do proper maintenance on the bike before your trip and don’t anticipate any problems. It really is rare that a major problem would occur; it is just as likely that any other component could fail due to lack of maintenance or a crash.

There may be someone out there hardcore enough to promote going with a rigid fork, but I can’t see that for when conceiving of a bike that can both tour comfortably and ride some gnarly off-road trails when needed or wanted. But feel free to prove me wrong! There have been some interesting evolutions in cyclocross designs of late.