I'm carrying a Canon 5D Mark II with me on my trip from Alaska to Argentina (just reached Colombia this morning). My Body + 24-105 lens are in my handlebar 95% of the time. The other 5% is the body + 70-200 f4. I have four lenses with me, the three that are not on the body are stashed away in my (front) panniers. Yes, it is a heavy load but I can take great pics