I currently use the older model Gossamer Gear Gorilla which has some wicking mesh on the back, but it rides right against my back. With temps in the 50's F, my shirt isn't very wet from sweat anywhere except the back. My back is completely soaked as if it were 100 degrees out, and the sweat even starts to soak the back of my pants after a few hours. Except for this minor issue, the pack is great.

Some Osprey packs have the ventilated mesh back which is not in direct contact with the wearer's back. I think the extra half pound of something like an Osprey Exos 40-ish liter pack would be worth having a drier back as long as the pack is as comfortable as the Gorilla. I rarely carry more than 15 pounds total weight (including food and water).

Has anyone tried both an Osprey with the vented back and the Gorilla? Or tried the Osprey and packs with a minimal frame similar to the Gorilla? Any Osprey users want to comment on the comfort of their pack?

I used an Osprey Manta last week while day hiking in Maui. No issues for me, the back panel provided plenty of ventilation. For warmer climates, I'd recommend it.

I want to like the Osprey packs, but they hate me. They are the most uncomfortable backpacks I have ever tried. Make my back and hips very sore within a few miles with a load in 'em. This is a 50-50 thing, people seem to love or hate them, they either work or not.

It's always best to try packs with the gear you intend to take so the general advice is, get a pack that fits you (fit is the top three most important things in choosing a pack - it has to fit, has to fit, has to fit) and works with the weight and bulk of your gear.

The mesh is nice - the big bow in the frame of the pack made a bear canister impossible to take in the earlier models. I noticed that the frame is less bowed than in previous Osprey packs when checking out the packs in REI the other day. But that of course means that there is less air space than before. I thought it was nice too that the hydration bladder could be hung in the air space, but alas, the frame felt like I was hauling a ton of bricks and tippy besides. The weight either settled on my shoulders or tried to pull me backward. So Im glad to see they revamped the frame since them. But the new ones don't fit me either... had to carry one for someone when they were having issues, and yep, same painful hips.

I tried the Exos and the Atmos (heavier clone of the Exos), and noticed my back didn't sweat as much. However, in good old Ohio summer heat and humidity, I did still sweat. I now use an Osprey Kestrel 48, which doesn't have the trampoline back. It doesn't seem like my back is particularly wetter or drier. Of course, I adjust the tabs and straps such that, while I walk, the pack isn't hugging me - weight on my hips; the shoulder straps mostly keeping the pack from falling off - so I still get some air movement across my back because the pack isn't in full contact all the time.

In colder weather, I did notice that my back was noticeably cooler with the Atmos/Exos packs. Not necessarily a good thing when you're not sweating.

I just could never quite fall in love with the Atmos, and the Exos was just too light a suspension for my taste (kind of like the Talon is a too-light version of the Kestrel.) But that's a personal preference. IF THEY FIT, the Atmos and Exos are good packs - I have a buddy who hikes in Virginia (summer and winter) and loves his Atmos 50 and 60 packs. When he goes west, though, he usually takes his Dana Designs Bridger (it may have to do more with how long he'll be out than anything specific to the pack - the Bridger may have more capacity?)

Like Lori, I haven't yet found an Osprey pack that is comfortable for me, whether unisex or woman-specific. They just aren't made for my body! Admittedly, I haven't looked really hard because I prefer a lighter backpack than Osprey makes.

Glenn has a good point in that if the pack is properly adjusted, the weight will be almost entirely on your hips, so the pack isn't in full contact with your back all the time.

The most important aspects of a pack are fit, fit and fit. IMHO, nothing else matters!

The "trampoline" suspension used with some of the Osprey packs has much the same issue as do packs that use lightweight sleeping pads as part of the suspension. Both systems put a fairly thick layer of lightweight material between the heavy part of the load and the users back. With the Osprey packs this is a "layer" of air: with packs such as the SMD Starlite it is a layer of sleeping pad. With a light load this is not much of a problem but as the pack weight increases it creates more leverage against your shoulders. Some people don't mind this "cantilever" effect; others, myself included, find it uncomfortable ( eg. Sore shoulders). In fact, I now use a single layer of CCF in the pad pocket of my Starlite and carry my sleeping pad on one side of the pack to minimize this cantilevering. So, IMO, you are faced with a potential trade off between sore shoulders and a sweaty back.

Have used quite a few Ospreys over the years, going back to when they were built in Colorado.

The only one I've had with a trampoline-style frame and back panel is a daypack--Atmos 35 IIRC. Less sweaty than a foam-and-fabric back panel that hugs my back? Absolutely. Eliminates sweat? Nope, I still sweat. But my back doesn't become soaked to the point of dripping.

I can't comment on the weight hit of this type of suspension, but do note it impacts capacity. The very curved main compartment won't hold as much as a similarly dimensioned bag having a more typical pad-and-framesheet back panel. Large, rigid items are tougher to stow, but this may not be an issue with larger overnight packs.

Have never used an Exos but think it's save to conclude its back panel will perform similarly to the Atmos. It will be less sweaty than any pack that places padding directly against the back, regardless of the facing fabric. If you don't have circulation, your sweat can't evaporate.

Cheers,

If you use the "optional" stays and the load lifters in the Starlite, it should work fine. I have SMD's old (discontinued) Comet which is basically the Starlite's little brother, and it works fine for me. I always use the stays and keep the load lifters pulled tight enough to take all pressure off the tops of my shoulders (I have very pressure-sensitive shoulders). That way practically all the weight is on the hip belt and nothing on my upper back and shoulders. I keep the shoulder straps just snug enough that the pack doesn't bob around and pull me off balance. While I do sweat a bit more under the pack, it isn't excessive. If it's hot enough, I sweat anyway, and I hole up in the shade during the heat of the day (necessary with a dog).

Here's another viewpoint.

I used an MSR frame pack for many years. It had a full 2" ventilated space between my back and the pack bag.

My back still sweated from the exertion of carrying a load uphill. The air flowing through that ventilated space was very chilling. I did not like it.

I'm a heavy sweater and I typically hike in cool weather.

I didn't realize MSR made packs at one time; they don't show any on their website now.

I have an Osprey exos 58 and Gossemer Gear Kumo. With the kumo I get pretty dang sweaty, even with the air beam instead of the sitlite pad. I'm way less sweaty with the exos. And for me at least the Ospreys fit fantastic. The weight carries very well. The biggest issue is the waist belt, almost too short on the med pack while perfect on a large. I'm not a big guy, but I still went with a large as it just fit better. All other packs I use med size. So you really need to bring your gear into a store, load up a osprey and see if it works for you. Like shoes I can tell imeadiatly wether or not a pack will fit.

MSR sold the backpacks in the early 1970s. It was a Jan Sport frame modified to Larry Penberthy's specs. The trampoline back "pad" was 1/8" nylon cord tightly stretched horizontally from one side of the pack frame to the other.

Cool. That was about 5 years before I started. I wonder what made them quit making packs (maybe internal frame technology was something they didn't want to mess with)? Had they kept at it, they (Cascade Designs) would offer enough variety that you could assemble your entire kit within the brand. Maybe they'll get back into the business by buying someone out, like they did with Walrus tents.

Thanks for the info.

Had completely forgotten about MSR-branded packs. Teaming with JanSport makes since, given they were both in the Seattle area.

MSR's early focus was on reengineering climbing gear and sales to the backpacking crowd was a kind of spillover that didn't seem to direct their product development. All that changed by the time of the REI acquisition, of course.

Cheers,

Thanks for the feedback everyone. It sounds like it's worth checking one of these Exos packs out in person.

I'm also now looking at the Zpacks Arc Blast, which has a vented mesh back and is at least a pound lighter than the Exos.