"GoLite Quest 65 – Shoulder straps were too high off shoulders
Osprey Atmos 65 – shoulder straps were too high
Deuter ACT Lite 60 + 10 SL – LOVED the way this pack fit – but the straps rubbed against the side of my neck (anyone have any bright ideas on if this could be modified?)"
I'm going to put in my own 2 cent here. There have been 3-4 recent threads discussing pack fitting issues so you might want to check those as well to get an idea of what we were talking about. Since you don't explicitly say what size each pack was I am inferring from the other info that they were all smalls. Is that the case?
The short answer is that the shoulder straps should NOT really sit "on your shoulders". Ideally they should press on the front of your shoulders, holding the pack against your back. That is their main job – really almost their only job. So I think there may be a misunderstanding of what the "right fit" should be, and how the pack should work. The long (winded) answer follows.
There are variations between people as to how they like to wear a pack, and variations on what companies "recommend" as the range of correct torso lengths, and so on. All of this cause confusion about fit – it is totally common. Since companies try to stretch recommended range onto as few set sizes as possible, you are especially going to get variations at the short end of size (you) and the very long end. If you find a pack that is indeed too short, don't be afraid to try the next size up.
The approximate right position of the shoulder straps should be straight back from the tops of your shoulders with a fully loaded pack. Beyond getting a general idea which packs to try on, you should just forget for the moment about *everything else* related to torso length – recommended or otherwise. Give the strap attachment point plus or minus an inch from horizontal off of your shoulders – any larger deviations and things become very marginal. More than 1.5 + inches off and you are in bad fit territory.
Also when you find a pack that fits your torso right, even if you don't like it for other reasons, take out a tape measure and measure the distance from the middle of the belt to the level where the straps attach to the pack. Remember *that* number. In the future, if you find a pack that same measurement (you will have to measure it yourself and ignore the "recommended torso lengths") then that pack should also fit you well.
On the neck issue, my first thought is that you have a bad fit, or things adjusted incorrectly, or both. A pack with the correct torso that is properly adjusted should not be anywhere near your neck – the pressure points should be lightly on the *front* of you shoulders. Unless you have weightlifter shoulders, or are a two headed troll, the "digging" into you neck is probably NOT a style issue. It is probably a fit issue.
I'm going to go out on a limb and say %85 probability it is one or both of these issues – but we did have a recent thread/s from a guy who was a weightlifter who had that issue. Are you absolutely sure you are adjusting the load lifters and sternum strap correctly? If you continue to have this particular issue I would try on some longer packs. Actually is sound like you did but rejected them for what may have not have been legitimate reason.
Make sure the pack is long enough so that the straps are close to straight back when the pack is *fully loaded*. If you are trying them out empty or lightly loaded in the store then you can expect the pack to settle and the effective torso length to shorten with full weight. So make sure it really is the right length – minimal to no wraparound when fully loaded. If you then adjust the load lifters correctly (and sternum strap not overly tight)it should get the straps off you shoulders.
The above mentioned guy with the weightlifter shoulders had his neck issues fixed by getting a catalyst. However that might have been due as much to getting the proper overall fit as well.
One last thing – a totally legitimate definition of a "backpack" is "a belt with a bag of some sort attached". The shoulder straps, ideally, have only one purpose to keep the pack vertical (when there is a suspension system) so the weight transfers directly downward onto the belt. If you feel the shoulder straps are bearing a lot of weight, and as a result they dig, this is a sign you have a bad fit. You should feel like pretty much all the weight is on your belt and if you, for instance, loosen the shoulder straps a bit the pack should more or less rotate freely back at an angle rotating from the belt. It should ideally feel like the straps are holding the pack forward, but not up.
If I had to bet on this I would put my money on the fact that the packs that have the neck issue for you are actually too short, in spite of your in-store positive response to them. Likewise, perhaps some of the other pack were rejected prematurely.