I start with the wheels. They must be strong enough to tolerate all surfaces, wide enough to maintain traction in the mud of the Pamir Highway and compensate for the lack of shock absorbers, because as statistics prove these break first. As Robb Maciąg puts it: simple solutions = simple failures = simple repairs. No suspension, no shock-absorbing seat posts, no hydraulic brakes and other solutions that require specialised equipment and knowledge to repair.
I opt for the 26 inch wheels. They are more stable than 28′ and considering the worldwide popularity of mountain bikes it should be easier to find replacements on the way. Novatec cartridge bearings offer less resistance than ball bearings, and if one spares them salt and chemicals of European roads in winter, they will also go further.
Solid Alexrims DH22 with four chambers and 36 spoke holes are trickier to centre than their 32 spoke cousins, but they provide greater stability and endurance. For the same reasons I reach for the DT Swiss Champion spokes and lacing for 3 crosses. Such lacing best protects the rim against the forces coming from all directions, not only vertical overload.