I use and abuse a kifaru duplex frame with emr2 bag. It may a little more than an ultralight but it’s so comfortable I hardly know it’s on my back. I can cinch down small loads when scouting or pack out bulky 100 lb loads.
I wouldn’t worry about the weight of a pack! I can pretty much guarantee my body will be a lot sorer and tired at the end of a long day with a 40 lb load in an uncomfortable load in a 4 lb pack that is only designed for 30 lb loads than a 60 lb load with my kifaru!!!
I wouldn’t worry about the weight of a pack! I can pretty much guarantee my body will be a lot sorer and tired at the end of a long day with a 40 lb load in an uncomfortable load in a 4 lb pack that is only designed for 30 lb loads than a 60 lb load with my kifaru!!!