Obviously if you're going to cycle umpteen thousand miles on it, you want a good bike. We spent most of a day at St John's Street Cycles in Bridgewater deliberating over the spec and sizing of our bikes. Two weeks later a pair of Thorn touring bikes arrived, dripping with expensive Shimano componentry, twenty seven gears and (hopefully) indestructible wheels.
Bikes on a (steep and rocky) cycle path in Devon.
And here in Kalavrita in the Peloponnese.
Essentially they have mountain bike gearing and wheels, smooth tyres for low rolling resistance (later changed to Schwalbe Marathon XR, much better for rough roads and very hard to puncture) and touring bike geometry for stable handling with loads and a range of riding positions. The brakes are cantilevers, sadly a rare commodity these days but much the best thing for touring (V brakes are fiddly and demand more travel from the brake lever than drop handlebar brake levers give). The fat tyres soak up potholes but seem to roll every bit as well as 700C and the brakes are excellent.
You would have to look closely to notice it, but my bike (the one with the red panniers) is different in the two photos above. Initially I had a Thorn Nomad but I had problems with it shimmying when I put a lot of weight (more than 6kg) on top of the rear rack. I do have very long legs which makes the centre of gravity high, plus I keep the laptop in my handlebar bag to protect it from vibration so the handlebar bag is rather heavy (3.5kg). St John's Street Cycles very kindly offered to let me swap the Nomad frame for an eXp frame for the difference in price (ignoring the year of use that I had already given the Nomad). The differences may be hard to see in the photos but you certainly know it when you ride the bike laden. The eXp is incredibly rigid so no matter how much weight (so far!) I pile onto it, it doesn't wobble, flex or shimmy in the slightest. Although it costs a frightening amount of money I would totally recommend it to anyone considering a trip like ours. Ju has a Nomad with which she is well pleased (the smaller frame is more rigid anyway) but if she had her time again she would also get an eXp. The rear triangle is made from bigger tubes and the main frame tubes are conical with one end standard sized and the other end 6mm bigger in diameter. All the details are on St John's website.
The componentry is almost entirely Shimano Deore XT. The bottom gear is 18" (and believe me we've used it!) and the top gear is 109". I have a Brooks saddle on mine with which I am very pleased, and Ju has a Terry Ladies Liberator which she is also very pleased with. The story with both these saddles is that they initially don't feel as comfy as a normal gel saddle, but after a few tens of kilometers they pay off! The brakes are Suntour self-energising cantilevers. The rims are Sun Rhynos.
The pannier racks are also from St John's, they are tubular 531 steel brazed together with lugs. The paint fell off almost immediately but otherwise they are very rigid and solid. The three bottle cages are very handy as two of them are fitted with expanding bottles cages that take standard Sigg aluminium drink bottles or fuel bottles. The standard bottles are useful because bike bottles always leak when you toss them in a rucsac, and keeping that stinking petrol out of the panniers is a great bonus.
My bike has a Schmit dynohub which can power two 3W front lights when going reasonably quickly (faster than 20km/h), plus it powers the battery charger gadgetry. Ju's has a Bosch and Mueller side driven dynamo. The rear lights are LED types, mine is something special!
The bags are all Ortlieb (except for the two fitted to my frame which I made specially). Fully waterproof and very hardwearing, I think they are great. We also have Ortlieb drybag rucsacs as extra bags to tie to the rear rack between the panniers if we need to carry extra food. Ju keeps her sleeping mat in hers.