The Trekker 3900 has been discontinued. If you're looking for something new, check out the best external frame backpacks for 2020.
Historic Range: $79.97-$179.95
Reviewers Paid: $100.00
Well, I just joined Trailspace and saw that no one has reviewed the K3900.
I’ve had this pack for several years now and it’s the only pack I own and know anything about. I’m 5’7 155lbs (this pack dwarfs me).
I mostly hike within short driving distance of East Tennessee (Knoxville) so I’ve packed extensively in the Smokies, Cherokee National Forest (mostly South Cherokee), and Big South Fork. (Eastern woodlands etc…)
I’ve found this pack to be incredibly durable; nothing has ever broken on it (or even come close.). I don’t keep records but I’m pretty sure I’ve logged a couple thousand miles with this pack over the last 5 years or so. I’ve heard people describe the toughness of a pack in terms of “throwing it down a ravine and going after it”; I’ve actually done that with this pack and it was no worse for the wear.
I can’t yet compare its comfort to others but I find it very comfortable with any load attempted thus far (max for me is about 45lbs or so). The mesh back-panel works well for me. (Although I still don’t quite get the selling point of “ventilated” packs as if they will reduce sweat: where are these peoples hiking that they don’t sweat?)
It is very easy to overload the external pockets and throw the thing off balance.
This is definitely not an “off-trail” pack as the massively square frame will seemingly go out if its way to grab branches and arrest your progress.
Summary of Pro’s and Con’s:
Very effective suspension
Encourages the wearer to walk upright
Lot’s of pockets (only a plus if you like pockets, I guess)
Mostly waterproof (been poured on many times without the inside getting wet)
Has shelf to strap stuff to (thereby increasing its capacity)
Heavy by modern standards (mine weighs 5.8 lbs empty)
Very square (making it really only good for open trail)
Makes you look a little funny when wearing it (someone called me “Sponge-Pat-Square-Pack once”), oh yeah and I scared a horse the other day (the rider blamed my big pack)
Doesn’t balance well side to side
Price Paid: $100