Ask anyone what the best bike for a trip to the bottom of South America is and you will get a million opinions. None are wrong. The reality is that there are a million different ways to ride that trip, or any trip really, and the needs from a bike vary big time depending.
What you need to figure out first is what kind of riding you want to do on the way. With that in mind, you can realize what you NEED, and start figuring out what you can sacrifice. No bike is going to have it all.
We knew going in to it that we wanted to try and spend as much time as possible off pavement and hopefully ride plenty of trails along the way. That taken into consideration with many other factors led us to using mid 90's Honda XR600R's as the base for our bikes.
Here's a break down of all that went into our decision and our opinions on the factors involved.
LENGTH OF MANUFACTURING:
When it comes time to find replacement parts in remote places, having a bike that has been around for a while becomes critical. The longer your bike has been made the better your odds.
The Honda XR600R remained unchanged from 1992 to 2000. This makes used parts easy to find and keeps the cost of new OEM parts reasonable. Virtually any part of the XR can still be ordered new from Honda and is usually sitting on the dealer’s shelf. There are are also plenty of aftermarket parts and support available to built up a great adventure bike. Even though the XR600R was not sold in large numbers south of the boarder we still saw them all over the place. Another bonus is that every small city had a Honda dealer, and the XR250 is a very popular bike in latin america that shares several parts with the 600.
The ability to fix your bike with basic tools and bailing wire is essential if you plan on exploring all the remote roads that take you far from the city. Also, simple wiring and electronics will save you from headaches and expensive replacements on the road.
Every part of the XR600 can be fixed with basic hand tools found anywhere. The entire engine can be rebuilt with no specialty tools. The only electronics on the bike other than the stator are a regulator, coil and CDI. Spares of all can easily be carried. We burnt up one regulator and one CDI box over 35 000 miles. Valve adjustments are done with feeler gauges and simply adjusted with the rocker nuts, no tricky shims or procedures. The air cooled engine has no radiator or water pump to fail and the engine does not require any special synthetic oil. We ran whatever brand 20w-50 we could find without any issues.
The materials that make up your bike will determine what can be fixed in small towns and what will need to be brought to a big city. You will break things and you will drop/crash your bike no matter how good of a rider you think you are. Plastic fairings break and turn signals will be ripped off in no time. Crash bars help, but I feel its better to just not have anything that will break easy. Aluminum is impossible to repair outside of large cities and does not lend well to being bent and straightened without cracking. It is very unlikely that you will damage an alloy main frame but I would avoid anything with an alloy sub frame.
The XR has a full steel frame and minimal plastic to break. The stock subframe is too weak for luggage but with some bracing it will do the trick. Steel pannier mounts and racks are one of the most likely parts to be damaged in a crash, so having simple steel construction will allow you to get back on the road quickly.
People have ridden to the southern tip of South America on everything from Harleys to full blown Dakar race bikes. It all comes down to what route you will be taking. There is no wrong way to ride through the Americas, but we truly believe you will be missing everything that it has to offer if you don't spent a good amount of time on the dirt. Most dirt routes are in decent shape, but if you want to ride aggressive and fast then you better have a bike that can take some big hits, aka big suspension. The XR has over 11 inches of wheel travel and it let us ride 60 MPH on rough dirt roads without worrying about ditches and massive potholes. The bike could be thrown at just about anything. The down side to all the travel is a tall saddle height, making it a handful for shorter legged folks.
The weight and width of your bike will also play a big role in where you can go. The lighter the better, as long as you are not sacrificing strength. If you can't pick up the back of your bike unloaded then its too heavy. A narrow light bike can be lifted through tight passages and roadblocks and rally single track. Also, when it comes time to find a place to sleep in the city, most doorways are too small to fit a big GS through and leaving your bike on the street is not an option.
The XR600R is considered a pig in the dirt bike world but is feather light compared to most adventure bikes. The single cylinder layout is very narrow as long as you keep your luggage tucked in close.
We saw so many people on single cylinder bikes with massive side cases sticking way out, full of unnecessary things. At that point you may as well be on a wide GS. There is no point to ride a light bike if your not going to pack light.
Like all the other categories the choice depends on what you will be doing. If you plan of riding the Pan American the whole way south, then by all means get the biggest engine you can. But, if someone asked us which way to ride across the United States, we certainly wouldn’t tell you to ride the freeway the whole way, and we definitely wouldn't suggest to ride the Pan Am. It sucks. We gladly sacrificed our freeway speed for great off road characteristics and a good time on the tiny dirt roads we would be searching out.
At the same time, I personally would not go on anything much less than 600cc. Unless you want to constantly re jet the bike you will be hating life above 10,000 feet on a small displacement bike. Lots of people do it but its not for me. We wanted a bike that could hold 5th gear at high elevation and cruise over the washboard with ease. In the dirt speed is your friend.
All the big three make great midsize engines but none are simpler than the Honda 600R or 650L. They are overbuilt, make plenty of power and are extremely reliable. Our decision to go with the 600R over the 650L was simply based on wanting a kick-starter and that's not an option on the 650L stock. Unfortunately, the 600R is a fairly high compression motor, so we lowered the compression for the low octane fuel we would surely end up running in remote areas. If you don’t mind e-start and don’t want to get into the motor, the 650L would be a better choice.
The only thing that kills the single cylinder thumpers is high speed freeway miles. We limited our speed to about 60MPH/100KMH. The motor has plenty more legs in it but the high rpm will shorten it's life.
No matter what bike you choose make sure that the engine has a moderate compression ratio or an ignition tune for low octane fuel. It is not uncommon to have 84 octane be the only option in the mountains.
Like I said this is all our opinion. We chose good dirt manners over highway comforts, simplicity over tech and less over more. Maybe we were lucky, but neither of us had any major mechanical issues over 35,000 miles/56,000 kms and we beat the shit out of our bikes. They got smashed through the Baja 1000 course, slid across the pavement in Guatemala, spent days on end pinned in 5th across the antiplano, unseen drainage ditches at 60 MPH, waist deep water, 25 degree cold morning starts and traffic in 100 degree heat.
We sat high in the wind, asses sore on small seats getting passed on the freeway but neither of us would trade any of it for all the incredible places our bikes took us.