Depends how flexible your timetable and route is. Your route covers from the tropics to the arctic, from sea level to 5000m, and all possible climatic zones - tropical lowlands and will also pass through one the driest and hottest deserts which can also be one of the coldest and highest 6 months later and will cross Andes passes that can get blocked by snow most of the winter or are closed by high river levels. Bolivian and Brazillian secondary roads will be subjected to monsoonal wet seasons and can be impassable in any vehicle. Patagonia in the middle of winter may not be to many travellers liking although there are a few blogs detailing riding to Ushuaia in the cold season.

Trouble is there are plenty of other natural catastrophes to give you grief - widespread destruction of infrastructure such as in Peru, not long ago. Similar in Ecuador, earthquakes and huge landslips such as blocked the way south in Chile several weeks ago and is still not resolved. Then there are the roadblocks set up by locals with a grievance in several countries - Mexico, Peru and Bolivia being the main ones.

All part of the adventure, but a major factor will be how much time you are allocating. Three months gives you no allowance to react to the weather or the climate, while 2 years gives you more than enough flexibility

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Tony
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