Vortex 3500

While looking for a new backpack with a volume in the 3000 to 4000 cubic-inch range, I decided to try a Vortex pack since I read many good things about the company. A number of years ago The North Face used polycarbonate frame sheets in some of its backpacks, which noticeably added to the overall frame strength of those packs. Polycarbonate seemed to have superior strength to solely using either 2024-T4 or 6061-T6 aluminum for frame material.

Vortex's use of (removable) polycarbonate frame stays in their current dimensions at first glance seems to yield a frame that is at least as stiff -- although not as flexible -- as frames built with 7075-T6 aluminum. Vortex claims in its literature that its polycarbonate stays are "50 times stronger than aluminum." That statement is inaccurate and misleading.

First of all, most frames are made from aluminum alloys that are significantly stronger than pure aluminum. Frames also are manufactured using significantly different alloys of Aluminum as well as manufactured in different dimensions. For example, 7075-T6 aluminum alloy is several times stronger than either 6061-T6 or 2024-T4 aluminum alloy in equivalent dimensions. Furthermore, frame composition is only one factor in determining the load-bearing capability -- or strength -- of a pack frame. Frame design and appropriate flexibility are equally important factors.

Other considerations pertaining to polycarbonate stays include the fact that they cannot be reshaped from their original form and can crack or break. 7075-T6 aluminum in the appropriate dimension has equivalent strength, superior flexibility, can be reshaped, and cannot crack or break under use.

Nevertheless, Vortex has come out with a frame system that is superior to most other frames currently available. The polycarbonate frames certainly can support moderate to heavy loads well. I did experience a problem with heavy loads in this pack: I needed to tighten the belt to prevent the pack from slipping, but in so doing, I felt some discomfort in my rear pelvic area. At first, I thought the pain was caused because I compressed the frame too tightly against my pelvis. However, that is impossible since the belt lay between my body and the frame stays. An alternative explanation is that I compressed the foam padding to the point of discomfort. Unfortunately, I was unable to pinpoint the cause of that discomfort before I had to return the pack, but I refer to it here so that interested readers can check this potential problem for themselves.

The volume of the 3500 seems to be understated since it appears to be able to hold well over 4000 cubic inches. It's often nice to get more pack than you expect. Most of the additional volume comes from the sixteen-inch extension sleeve. There is a trade off with such a long sleeve: When this sleeve is folded inside the pack, it nearly reaches the bottom and can be a nuisance when removing gear from the pack. However when the sleeve is extended, it nearly doubles the pack's volume so that this single pack can be used to carry both small and mid-sized loads.

The pack bag is made from 420 denier untexturized nylon, 500 denier Cordura Plus nylon, and 1600 Junior Ballistics nylon that also appears to be texturized. In addition to an exterior layer of 1600 Junior Ballistics nylon, the pack bottom also has a second, interior layer of 420 denier nylon so the bottom is very abrasion resistant. Additionally in a number of spots that use 500 denier Cordura Plus nylon, that fabric exists in double layers for added abrasion resistance. The pack also has two tool tubes, two wand (not water bottle) pockets, a floating (but not waist-pack convertible) lid with separate hydration compartment, an exterior pocket along the back, and zipper access via two YKK number 10 zippers that open very nicely into the main compartment.

This is a single compartment bag with no interior dividing shelf, but the bag does have a single, internal compression strap, which is difficult to use when the extension sleeve is folded inside the pack. This internal compression strap is very similar to the one used in Dana Design bags. Most people I communicate with either really like or really hate these straps; I fall into the latter category.

The 3500's belt felt comfortable. The shoulder harness was another matter altogether. After several phone calls to Vortex's customer support department, I still could not get the harness to fit comfortably. In fact with several layers of clothing, I even had trouble getting the pack onto my back. At 5'8" and 140 pounds, it's not often that I am accused of being too large for a pack. Frankly, I can't remember when I had so much trouble getting a pack onto my back. My final call to Vortex convinced me to try the company's next largest pack: the STX.

I think Vortex's attempt to create a one-pack-fits-all with the 3500 failed. This pack certainly possesses enough volume to warrant (three) separate pack sizes. Perhaps Vortex will manufacture this pack in multiple sizes in the future. For the present, I found the harness so problematic that I cannot recommend this pack to anyone regardless of the pack's virtues. If you are looking for a pack in the 3000 to 4000 cubic-inch range, you might be better off trying either the STX or 4500 since those two packs can be fit with a higher degree of precision. Alternatively, you can try some other company's packs (I would recommend either the Gregory Makalu Pro or the smallest packs in McHale's SARC line).