I have made two significant changes to my 2009 Ohm. I added a mesh back panel, and I replaced the carbon fiber and Delrin rod with an aluminum one.

It is hard to avoid a sweaty back when the back of a pack is a bare waterproof panel. I added a two-piece mesh panel. This gave me a little more room inside, and allowed me to use the foam sheet as a sit pad on the trail and in camp. And it gave me a dry back.


The mesh by itself is a vast improvement. The foam sheet is a 1 ounce camp luxury.


I have never understood how a flexible hoop could effectively transfer weight to a hip belt.


I replaced it with a solid ¼" aluminum stay. Shaping the aluminum to match the radius to the hoop pocket looked like a challenge. But then I noticed the "Hydro Ports" on each corner – they were square, and right where they needed to be. So a "square cornered hoop", like a Gossamer Gear or a Six Moon Designs, came to mind. And it turns out the SMD Large was almost a match for my Medium Ohm. I needed to shorten the stays about 1.25" to get a perfect fit. The weight gain was 2.6 ounces.


This is one stiff, and comfortable, pack.

With these two mods, the hip belt pockets, a few extra straps, a watch and compass, and the dirt, the weight comes to 28 ounces. The improved performance is worth it.

Edited by greg23 on 12/08/2010 16:35:03 MST.

Did you have larger hip belt pockets put on my ULA? They seem ridiculously luxurious. You could put a ham sandwich in one and a beer in the other…

I don't know about "Your" ULA, but the pockets are big. I ordered them with the pack.

I can almost get a days worth of bars and gorp in one, and then a Canon G10 and a monocular in the other.

My only complaint is attachment. They will be sewn on by the end of the week.

Edited by greg23 on 12/08/2010 19:37:03 MST.

Nice mods Greg. If you don't mind my asking, what specific type of mesh is that and where did you get it?

Nathan,
I believe it is Polymesh that came from Quest. It is a simple, single layer, very open mesh.

It is typically used for pockets. Even though it is backed by a non-breathable, thin, foam sheet, the mesh greatly improved air circulation between my back and the pack.

Thanks Greg. I'm currently trying to decide on a good mesh-type fabric for a backpanel and straps for a MYOG project. Does the polymesh stretch at all? Also, would you consider it fairly strong stuff? Questoutfitters has the weight listed as 8oz/sq. yd. so it seems like it'd be pretty tough. All in all, I'm looking for something strong and non-stretchy that will add a little breathability. Thanks.

It isn't elastic. It will "distort" if you pull across the bias. I wouldn't say it stretches.

I've put a few hundred miles on mine and there are no signs of wear. However, a backpanel is far less stressed than straps. But, I would guess that it will hold up.

Edited by greg23 on 01/24/2011 07:52:50 MST.

What about thru-hiker.com 3D mesh - $9 per foot 42 inch wide, 1/8 inch foam

I've heard people mention it.

Check out Rockywoods.com for the strap/backpanel mesh. Cheaper than Thru-hiker and will work fine.

Ryan

You gave me an idea, I would love to do this, add the SMD stay to the OHM, shape it away from my back, and add a mesh trampoline back panel...maybe add it with wide 2" velcro top and bottom....hope it would work, been wanting to have a ULA with a trampoline backpanel.... any thoughts?????
sandy
sandylwes@yahoo.com
mabton,wa