>>1033856I'm not sure whether you'll want to go with 26" or 29"/700c rims, both are common in North America but I'm not sure what's readily available in South America. Do some research. 27.5"/650b will probably not be common down south.
There are a lot of nice mixed-terrain tires in the 40-50mm range for 700c wheels nowadays, but on the terrain you're going to be on, I think you're going to want to fit real mountain bike tires - 2.2" wide or higher.
That basically means you're going to be looking at bikes more along the lines of mountain bikes - think stuff like the Salsa Fargo, or Surly Troll and Ogre.
If you don't feel the need for full-on MTB tires, there are a variety of "adventure touring" bikes designed to fit up to 50mm 700C tires - Salsa Vaya, Specialized AWOL, etc.
Whatever frame you end up going with - steel frame, steel fork. Durable, and if it *does* crank out on the road, steel frames are repairable by anyone with half a brain and a shitty welder.
>>1033884Agreed that I'd favor drop bars; being able to shift hand and body positions will be important when you're spending all day in the saddle. Also agree that SPD pedals and shoes are the way to go.
Gearing: Triple chainrings, 8- or 9-speed cassette in the back, and friction shifters all the way - one fewer thing to worry about keeping in perfect adjustment. Keep on top of cleaning and lubing the chain.
Building the bike up yourself will teach you most of what you need to know about fixing it, but it will leave some gaps. Notably: take the time to learn how to true a wheel or replace a spoke.
