Trampoline back vented backpacks

You know the ones: Gregory Z55, Osprey Atmos, Deuter, etc. The backs of these packs have a mesh panel that in theory keeps the back cooler and drier.

Do you think they work?

The only drawback I know of is that it the design can infringe on the interior of the pack. The curve of the design eats into the space and makes packing harder.

Do you think that the design does indeed make your back cooler?

Yes, yes and yes.
In that order <img src="/forums/images/graemlins/cool.gif" alt="" />

Osprey has a new series coming out (forget the name) that seems to combine the Atmos and Talon series, saving weight and increasing capacity over the Atmos packs but offering a trampoline frame. We shall see.

I have an Atmos 35 that I use for a daypack, because the effective space isn't adequate for even lightweight overnights. But...it's really quite comfortable. A Talon 44 is my current favorite multiday backpack, but it's not nearly as cool as the Atmos.

YMMV

I agree. I bought the Atmos 50 last spring. I stuffed it full of winter clothes and lead shot weights and used it for training through the summer. I walked over 100 miles with it over the summer in high humidity and the trampoline back works very well for ventalation. However, it definitely interferes with packing it and being able to see what you are doing inside it. Other than that, I like everything else about it.

I'll probably keep it for training hikes. I'm considering a panel loader but not sure which one

I can respond in regards to the Atmos 50 -- it is cooler. It is harder to pack and unpack. It shifts the center of gravity further from my back. No pack is perfect. It is a good pack.

I've got the Aether and love it. Although it does not have the trampoline back of the Atmos, the back is mesh over a pebbly foam and it definately lets more cool air back there than the solid foam or solid fabric of some other packs. The reason I really love it however is that it is hands down the most comfortable pack I've ever had. Fits me great!

I've got the Atmos 50... yes, it keeps you much much cooler. I used it for a week trip this summer, and my friend was constantly much hotter than I was, and his back was always sweaty. I was much cooler than him.

It does push your center of gravity back a bit though, so it feels a little more like an external frame in terms of balance.

It also takes up some internal volume of the pack, though that's accounted for in the sizing of the pack... an Atmos 50 has the same internal volume as any other 50 liter backpack... it's just in a weird shape. That shape does take a little getting used to, but not really much at all. It seriosuly took me only 1 overnight trip to figure out how to pack the thing differently.

Anyway, I'm a huge fan of the mesh back, and don't know if I'd switch back. At least not for 3 season use.

I have a Tatonka "Bike n Hike" backpack that I use as my daypack. It has a trampoline back and there is no way I would go back to a non-trampoline back. This particular pack is well designed and the gap between the trampoline and the pack itself is quite slim, just enough to get your hand between them (which BTW is a great place to store my Bora hat when not walking). Also, inside the pack is very straight as the small gap allows it to follow the line of the metal stays which are only slightly bent.

A couple of weeks back we hiked in the Royal National Park in 33C (92F) temps with a hot, dry northwester and except for the hip belt my back was dry. As someone who sweats on the top half of my body the dryness was welcomed.

The trampoline doesn't stop sweating it just provides access for air to circulate and cool/dry your back. Ultimately you need to go to a decent outdoor shop and try some on and then decide which one you like.

Cheers,
Michael.

I have the Deuter Futura Zero SL 40 for overnights. Just used it once and had a bit of an issue with it being bouncy. Like my center of gravity was off a bit.

I have the Deuter AC Lite 25 daypack and love it. I do think it makes packing harder. Also the Deuters fall over if you try to sit them on the ground...not sure about the others.

I do think it helps with ventilation on all but the most humid trips. I notice a big difference in spring and fall but only a bit in the middle of summer.

Unlike the Osprey's the Deuters have an open mesh bottom and you can't put your bladder in there. A couple of people I hike with have the Osprey's and put the water bladder in the mesh in cooler seasons to get more room in the pack.

Millette J

Yes, the bladder must go behind the trampoline. Otherwise it's impossible to remove and replace without unloading the pack, not to mention it reduces space. I used it hiking out of the Grand Canyon in August and didn't have any issues with the water getting uncomfortably warm.

I think overall, the trampoline is a great idea, especially in warm climates.