I assume 'i' is one person. For 2 up i'd suggest a 950.
for rtw and sand i'd suggest a 640 but why get a 640 when for the other 80-90% of the time the power and smoothness of a 950 would be so much more fun?
once you get to the sahara - depending on route etc you may find a 4x4 to help carry some stuff - assuming youre going in the same direction
It also sounds like you are a bit heavier than me (im 160) and stronger so picking up the 950 wont cause any problems.
engine reliability -
640s inlet rocker arms last 40,000km. easy to replace before they fail.
friends with 950s have had quite a few problems but the lastest bikes should be much better. ktm want to move into road bikes so cannot afford them to fail.
however, i didnt choose a 950 because i know i'd kill myself by going too fast. a 640 is is quick enough for me, a lot of fun, simple and i can do most work on it myself.
try before you buy - can you not get a demo rides/borrow both and try some local sandpits etc?
the worst thing is to choose a bike youre not happy with.
if you start in north america with what you think is best & plan your mix of roads right to test everything but find your choice drives you nuts you might still (with huge amounts of planning) be able to sell current and buy the other one in the usa/mexico/south america before hitting the carnet countries where you cant sell your first choice.
Last edited by Jerome; 19 Apr 2006 at 21:27.