For those who use CF packs: It seems to me that the straps and the back of the pack would cause excessive sweating where it is in contact with your shirt/jacket/vest. Is that true?

With any pack, my back is usually soaked with sweat so I don't really notice a difference with cuben. The nice thing about a cuben pack is that the material itself doesn't absorb the moisture so your pack stays dry. This is nice if you want to use it under your feet at night.

It'd be nice if they let your incorporate your sleeping pad into a sleeve to use as a support, like my GG Mariposa. This would keep the non-breathable CF off your back.

The other nice thing with 'non-breathable' cuben is that you don't have moisture getting into your stuff. It's not a big deal, but I'd prefer to keep the inside of my pack as bone dry as I can. The less humidity that creeps into my clothes the better.

Plus think of all the weight saved by not having a backpack that's soaked up sweat :) I really don't think there is much of a benefit to having a 'breathable' material like 210D nylon against your back rather than cuben, since either way I've got a totally saturated back that isn't going to dry until I take my pack off at the end of the day.

There are designs that allow for air flow back here, but they pretty much always move the pack bag further away from your back which messes with your center of gravity. The sleeping pad idea is a reasonable one because it doesn't move the pack too far from your back (like a lot of Deuter packs), but it's still a whole lot of insulation right against your back that is going to lead to a sweaty back. As far as I can see, a sweaty back is pretty much unavoidable and it's really not that bad. A sweaty back is usually a warm one.

Edited by dandydan on 05/04/2011 21:08:39 MDT.

"As far as I can see, a sweaty back is pretty much unavoidable"

Hmmmm. We'll see about that.....

What if the pack isn't against your back?

Edited by idester on 05/04/2011 21:48:36 MDT.

osprey's exos has a nice trampoline back that really does a nice job of allowing air to keep the back from being soaked. my cuben fiber pack does make my back sweat a good bit...

Doug, that new pack is pretty creative and neat. Hopefully it works out.

Josh, the Exos moves the weight away from your back with its 'trampoline' system. This affects your center of gravity (C.O.G) and basically requires you to lean further forward as you walk to counter the weight being further back. There is a lot of good reading on the important of C.O.G. over at the Aarn packs website. I personally would rather have a sweaty back than use a pack that moves the weight back away from my back.

i have yet to feel unstable or any sort of "pull" backwards or that my posture was negatively affected, while carrying my exos. it is a matter of 2 inches. do you have one or are you just basing your ideas off of reading?

Josh, its been observed by many (including myself) that trampoline packs throw off your center of gravity. Back before BPL, I had a deuter pack with a trampoline, and it definitely pulled against my shoulders more than any other pack I've owned. You tend to notice it more with heavier loads. Anything that rides closer to your body will feel better. It's the reason why people say the GG gorilla rides better than the GG mariposa plus even though they both have the same pack design. The Mariposa rides further away from the person's back (because of its larger volume) when compared to a gorilla.

Edited by Konrad1013 on 05/05/2011 22:34:56 MDT.

I do not have a pack that has an airspace between my back and the packbag. My comments are based on reading and on my general experiences with packs affecting my center of gravity.

Virtually all backpacks move the walkers center of gravity rearward, since weight is being added only to the backside of the torso. The exception to this is something like a properly loaded Aarn pack with its additional compartments on the front. It is my experience that this rearward moving of the C.O.G. is a bad thing and that it should be minimized. This is supported in a lot of literature, such as Andrew Skurka's new book (pg 29).

I find moving the C.O.G. rearward to be a bad thing because it requires that the walker lean forward to counter it out. This forward leaning may not cause obvious problems, but I find that it contributes to overall back soreness, it pulls back harder on my shoulders (more soreness) and in more extreme cases I find it lowers my enjoyment while hiking because I'm actually leaning forward several inches and I wind up staring more at a my feet when I hike, then at the beautiful surroundings. In addition to soreness and lower hiking enjoyment, literature on the topic argues that it's a less efficient way of walking (see Aarn's website).

Besides an airspace, there are a lot of other factors that determine how much a pack affects your C.O.G (ie. pack weight and where the weight is). So while I haven't used a pack with an airspace, I have used many packs that adversely affect my C.O.G. to varying degrees. I'm not saying that an airspace is the worst thing, just that the less a pack affects your C.O.G. the better. I'd rather have a better C.O.G. and a more sweaty back, than a less sweaty back but accept the downsides mentioned.

While I'm on the topic, I want to mention that pack compression systems that compress the pack bag horizontally (ie. thinner) are preferred because they improve your C.O.G in addition to adjusting the pack volume. The ULA Ohm is a great example of this. A vertical compression system (ie. roll top) works well to reduce the volume of the pack bag but it doesn't improve C.O.G. which is a missed opportunity. Many packs have both (ie. roll top plus side compression straps) so a wise hiker may opt to use the horizontal ones before the vertical ones.

Edited by dandydan on 05/05/2011 23:01:48 MDT.

> i have yet to feel unstable or any sort of "pull" backwards or that my posture was
> negatively affected, while carrying my exos. it is a matter of 2 inches.
> do you have one or are you just basing your ideas off of reading?

Simple high school physics should suffice. Load up a pack that doesn't rest against your back, and you'll start screwing up your balance.

There's a reason that it's limited to packs intended for low capacity loads.

I agree with Dan. You want the pack bag as close to your back as possible. I would rather have a sweaty back then be off balanced all day..

I sweat in the front also. How slow do you have to hike not to sweat?

are you kidding me? 11 lb baseweight in that pack has never thrown me off balance or made me feel unstable. i'd happily recommend that pack any day of the week. that said, i like my cuben zpacks pack as well.

Maybe you ought to read the entire thread instead of skimming next time you reply...

I'm a heavy sweater (no, I'm not made of wool). My back will always be wet when backpacking. Pack fabric isn't the cause.

I had an exos I sold it

My back got just as sweaty with that pack as my packs

That being said I had Joe make me a 1500 ci with side and back pockets and a small belt and I love it.

Easy weekend pack for 7 ozs

Carries great with minimal gear

I think, in light of the packing strategy of the lion's share of this community, that coming down hard on a pack like the Osprey with a trampoline construction is somewhat laughable.

Most people on here carry frameless packs, using a CCF pad folded up against the back to form a frame. Depending on what sort of foam is used, this is effectively moving the load off the back by between 1/2" (folded over thinlight, thin sit pad, etc) and 2.5" (zlite, folded nightlight, etc) so in some cases, more than the Osprey pack does. Nothing is ever said about this, but the effect is the same, that is to say minimal in light of the loads most of us carry.

EDIT Post removed because it was filled with fuzzy logic and poor observations. Sorry, science was never my strong point :)

Edited by Konrad1013 on 05/07/2011 12:33:27 MDT.