Rating: 4 / 5
I received the Jam2 only a week ago, but I did manage to get in a 3-day 60-miler, as well as a short dayhike, which were fine opportunities to get a feel for this pack. (I carried a 7-day food load for testing purposes.) So far I’ve found it to be very thoughtfully designed, not perfect but certainly a keeper.
My torso is 18 ½” long, but the size L fits me best (sizing up one size from GoLite’s recommendations). This jives with BPL’s Frameless Backpacks Analysis, which states that GoLite “underestimates user torso lengths for their packs by a half to full size (1.5 to 2.0 inches).” Thank you BPL, for helping me get the right size on the first try! I prefer not to make noticeable compromises on pack fit.
The large volume of this pack surprised me. A 7.5 lb kit, w/ a 22 oz arc alpinist packed loosely in the bottom, still leaves room for at least 10 lbs / ~800ci of food (7 days). More volume could be made available with careful packing. With a total packweight around 20 lbs the Jam2 was very comfortable on long days. Caveat: I’ve never owned a light pack that didn’t require some tinkering with packing techniques to achieve a good feel—this one’s no exception. So far I have yet to come up with a comfortable configuaration for a 25-lb load (9 days of food/esbits + 2L water), but I’ve not yet gained a lot of experience with this pack either, so take that as an indication of the learning curve only. For a virtual frame, I used a 32” long Ridgerest rolled cylindrically, but soon I’ll switch to an Evazote pad cut to slightly smaller dimensions. There might have been some torso collapse at this weight, which could partly account for the torso-length discrepancy—I’m not positive.
The shoulder straps are judiciously padded, short of Vapor Trail cushy-ness. The removable backpad is ¼” thick. The hipbelt has no padding, and I don’t see that it needs it. However since the hipbelt is so flexible (just a double-layer of fabric), one has to be careful that it wraps smoothly around the hips, particularly not allowing the buckle to ride too high, which distorts the downward-sloping fin shape.
Having gotten a proper fit, I can say for certain that the Jam2 is more comfortable than the Granite Gear Virga (also frameless), and as comfortable as my Vapor Trail (light framesheet), at ~20 lbs total packweight. The latter two packs are more heavily padded, but GoLite gets the core suspension issues right.
The zippered outside pocket is cavernous, and the waterproof zipper runs smoothly. Apparently this pocket re-design was a major goal for improving the older model, and GoLite has done a good job getting more volume out of a similar amount of fabric. The pocket can hold an obscene amount of gear: cocoon pullover, nano tarp, vapr bivy, full raingear, pack cover, and some small items. In fact I had to resist the urge to pack too many dense items so far from my natural center of gravity, as the shoulder straps are not up to the torque. Unfortunately there is no way to compress the excess fabric of this non-stretch pocket when it is left empty.
With four side compression straps, one top strap, and the bottom compression clips, the main packbag shrinks impressively (the latter pics show the maximum compression possible, including a closeup of the bottom clips). The Jam2’s compression is an improvement over many light packs, but that doesn’t say alot. I did appreciate this though, since for me this pack is a bit big.
The mesh side pockets are too short, or at least too sharply angled forward, to stabilize a full 1L collapsible Nalgene. On technical terrain, I will probably use the lower side compession strap to secure it in place. It’s kind of dumb to have to do this though.
The stock weight of my Jam2, size L, is 21.44 oz. The fabrics and construction are obviously robust, and I wouldn’t change that since we all know there are light and fragile packs for the picking already. There are many options for reducing the stock weight: at the least, I will rip out the hydration sleeve, trim a lot of excess strap-lengths, replace the drawcord and cordlock with lighter options, and at low packweights I may remove the backpad completely (except on very cold trips when the extra ground insulation might be nice under one’s legs). Hopefully I can find lots of smaller things to snip too. 18 oz modified weight seems a reasonable goal.
The 1 point demerit because:
1. compression straps, even when supplemented with GoLite’s clever bottom clips, are still inferior to good ol’ criss-crossed cord compression IMO,
2. the side pockets are too short,
3. the kangaroo pocket could lose the zipper, and be made from stretch mesh with an open top for drying wet gear (climbers dangling upside-down as they read this will disagree I suppose).
Overall I’m happy enough to make it my go-to pack of the moment. Possibly it has one of the better frameless suspensions available for sub-25 lb loads. However, based on a few features, my dream pack still eludes me.