I have a 2008 Jam that I have been reasonably happy with. I have a 19.5" torso but find that the Large in that version to work well (I have a larg'ish chest measurement).

My buddy has a similar build and purchased a 2009 version. However, is is having some issues with fit. I tried it on loaded with about 15lbs and found that the main bag was about 3" away from the top of my back (i.e. there was a 3" space between the pack and my back toward the top). This is the same situation with my friend. I can't see the torso sizes changing between years, but it suggests that the additional exterior pad is pushing the back away when it is fully loaded and 'stiff.'

Has anyone else found this? Should he drop a size to Medium? Would this allow more natural contact with the upper back?

Anyone else observe this? Am I nuts? (don't answer this)

I tried one on with 20 lbs...medium and the bag kinked about 1/3 way down....

I've got a 2009 Jam. I'm 5'11, 160lbs with a 18.5" torso. I'm loving the medium fit.

Dan - how do the shoulder straps sit? Do they curve nicely over your shoulders? How far below your shoulders is the shoulder harness attached to the main bag?

With 16 pounds dead weight, ie. 2 8lb. dumb bells, there is no gap. The shoulder straps and the remainder of the bag hug my shoulders and conform to the shape of my back snug against it. (5'9" 18 " torso, size M pack).

"How far below your shoulders is the shoulder harness attached to the main bag?"

Doesn't that depend on how tightly you have adjusted the shoulder straps? When the straps pulled tight, the point where the shoulder straps are attached to the pack hans only a couple of inches below the top of the shoulders.
For instance, if you hang the shoulder straps over your arm when holding the portion of your arm between your hand and elbow parallel to the ground, the pack will just hang slightly down off the curve of your arm as it would when over your shoulder.

Edited by rambler on 09/14/2009 13:58:35 MDT.

Thanks Frank!

I'll load mine up and check this out tonight. I'm at work now :)

Thanks Dan.

Dave,

I'm 5'8", 150 and have access to both a 2009 Medium and 2008 Large. The 2008 Large fits me great, but the 2009 Medium fits me better. I don't think you're crazy....

Can't help with the 2008 to 2009 comparisons, but I have both the med. and Lrg 2009 Jam2's and I have a 19-19.5" torso.

The Large fits or feels hands down better for me over the medium.

Back panel measurements are as follows:

2009 Large Jam2 is 22" from the bottom of the pack-bag to the top inside edge, where the shoulder straps attach to the pack.

2009 Medium Jam2 is 20" from the bottom of the pack-bag to the top inside edge, where the shoulder straps attach to the pack.

So basically a 2" difference on the 2009 model sizes.

Edited by mfog1 on 09/14/2009 18:11:10 MDT.

Here is a photo of me wearing my Jam. As a reminder, I am 5'11 between and 6'0" and this morning I weighed 158 lbs in the buff. I used to weigh about 170 lbs before I moved to Whistler, BC and became so darn active. My torso measures between 18.5" and 19.5" depending on how you measure.

This is my 2009 Jam loaded up with roughly 10lbs of stuff...mostly just pillows from my couch. As you can see, the straps connect to the pack just an inch or two below my shoulders. I think this is about perfect. The torso is just long enough that the hipbelt sits on my hips. If I had another inch or so of torso it might be too short.