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Mountainsmith Fusion 35 Backpack REVIEW

An all-day, off-piste or hut-to-hut snow sport pack with features that might just validate the weight.


by Jay Ham | 2006-02-12 03:00:00-07

Mountainsmith Fusion 35 Backpack REVIEW


New for spring 2006, the Mountainsmith Fusion 35 Alpine pack may be perfect for an all-day, off-piste ski or hut-to-hut trip. It is absolutely loaded with features intended to make carrying snow sport gear easier. Its 2014 cubic inch volume and exceptional durability make it suited for extended trips where a typical hydration pack will leave you short. After four months of testing, I have really gotten to know the performance qualities of this pack. Are they enough to substantiate the 54.1-ounce weight?

What's Good

  • Competitive weight for a snow sport pack
  • Able to hold skis, snowshoes, ice axe, ski poles, and avalanche gear simultaneously
  • Internal frame stay and supple padding make for comfortable load hauling
  • Volume is perfect for an all day ski or lightweight hut-to-hut trip

What's Not So Good

  • Side panel pockets are too small to hold water bottles
  • Main compartment access is difficult with skis attached
  • Hipbelt pockets are too small to accommodate a digital camera





2006 Fusion 35


Internal frame, top loading, drawstring closure, attached top lid


Size Regular tested: 2014 ci (33 L)


3 lb 6.1 oz (1.53 kg) measured weight; manufacturer's specification 3 lb 3 oz (1.44 kg)


Main body is 210d nylon Cordura, wear areas are 420d nylon Cordura, front stretch pocket is 500d nylon Kodra, Hypalon reinforced contact points for skis and ice axe


Fixed top lid, 8-inch extension collar with drawstring closure, zippered top pocket with key clip, two side compression straps, stretch-woven front pocket, one ice axe loop, 3-liter hydration sleeve with one port, haul loop, load lifters, hipbelt stabilizers, sternum strap, gear specific attachment points for skis, ice axe, snowshoes or snowboard, and trekking poles

  Volume To Weight Ratio

37.2 ci/oz size L (based on 2014 ci and a measured weight of 54.1 oz)

  Comfortable Load Carrying Capacity

25 lb (11 kg) estimated comfortable load for an average person carrying the pack all day

  Carry Load to Pack Weight Ratio

7.86 (based on 25 lb and a measured weight of 3.18 lb)




With one of the lowest volume to weight ratios of any pack we have ever tested (37.2 ci/oz), one might wonder why we tested the Mountainsmith Fusion 35 at all. And if this pack were designed for backpacking, we probably would not have. The Fusion 35 is a dedicated snow sports pack with enough volume to handle a long day or hut-to-hut ski trip and features to carry all the tools (or toys) you will need for the trip. The Fusion 35 is one of five models making up the Mountainsmith Alpine pack line, a new line for 2006.

In the world of lighter weight snow sport packs, the weight of the 54.1-ounce Fusion 35 is comparable with similar volume ski packs. The Osprey Switch 25+5 weighs 65 ounces, the Granite Gear Contrail 58 ounces, the Black Diamond Snow 35L 49 ounces, and the GoLite Delirium 43 ounces. So while it might not make the cut as a lightweight backpacking pack, it certainly competes well among other snow sport packs.

For a pack this small, the frame and suspension are over designed to handle the heavier weight of snow sport gear. Mountainsmith uses an HDPE framesheet and single T6 6061 concave aluminum stay to provide support. The concave shape of the stay is apparent when looking down the stay, and is designed to add stiffness to a thin material. The stay comes pre-bent, but will likely need tweaking for a perfect fit. Opening a Velcro closure provides quick removal of the stay. I added a little more curve to the lower half of mine, by bending the stay over the rounded surface of my office chair, to increase the amount it cupped into my lumbar. The pack is not dependent on having the stay; removing it along with the PE framesheet cuts the weight by 6.5 ounces and leaves the molded backpanel padding behind. The stay is welcome when carrying the extra weight of the gear this pack was designed for, and does an excellent job supporting it.

The padding in the shoulder straps, hipbelt, and backpanel is super supple closed cell foam. The shoulder straps measure 3 inches at their widest point. We are starting to see a trend to wider, more supple shoulder straps in the backpacking industry, which is a welcome change. Some of the first packs with really wide shoulder straps came from Gossamer Gear; now others are following the idea with good results.

The shoulder straps are fixed to the top of the backpanel. However, some adjustment is still possible by raising and lowering the hipbelt. The hipbelt is fixed behind the padded backpanel with a single, vertical strip of Velcro. The hipbelt can also be removed, cutting 8.5 ounces. The hipbelt and backpanel use dual density foam - a stiffer density behind to support the shape and a softer density for comfort against your back and hips. The Fusion 35 has a sternum strap, top load lifters, and hipbelt stabilizers to dial in the fit.

When fully loaded with skis, poles, avalanche gear, snowshoes, and a day’s worth of gear and food, I found the suspension and frame very comfortable. I tested the Fusion 35 with such gear at weights between 20 and 25 pounds. To test further, I loaded the pack with 30 pounds of books and gear, and found it would handle this weight comfortably too, but perhaps not for an entire day; besides, it is very difficult to fit that much gear in a 2000 cubic inch pack.

Mountainsmith Fusion 35 Snow Sport Backpack REVIEW - 1
Mountainsmith hit the mark with supple padding, wide shoulder straps, and a single aluminum stay. The Fusion 35 can handle a lot of weight for a 2014-cubic inch volume pack.

What sets the Fusion 35 apart from an ordinary backpack is the tool specific attachment points. I hoped to find a reasonably durable ski pack that could carry skis and snowshoes at the same time and hold enough gear for a day of hiking and skiing. In the mountains of Arizona, our transition season snow tends to be a good jaunt from the car, hence my interest in carrying both skis and snowshoes. The Mountainsmith Fusion 35 fit the bill with regard to its carrying power.

Designed to carry skis in an A-frame configuration, the Fusion 35 carries a ski on each sidepanel using two nylon webbing straps with side release buckles and Hypalon reinforcements. I found skis carry best when they are strapped together at the top (the skis’ nose) to stabilize the A-frame shape. This also kept them wider at the bottom and away from my calves when hiking. The same straps that hold skis on one side panel extend to mate with those on the other side panel to attach a snowboard or snowshoes to the front. In addition to strapping on gear, the side panel straps also compress the entire pack load.

Mountainsmith Fusion 35 Snow Sport Backpack REVIEW - 2
The side panel compression straps (left) are designed to hold skis. They have Hypalon reinforcement to reduce pack wear. These straps also connect to their mates on the other side panel to attach a snowboard or snowshoes on the front (right).

The Fusion 35 holds a single ice axe in a sleeve on the left side. A side release buckle allows one to remove the axe by sliding it down. The buckle, being firmly attached to the ice axe sleeve, is slightly difficult to open while wearing gloves because you can’t really get your fingers around it. The sleeve is reinforced with Hypalon along the bottom edge, and has a Velcro tab at the top to adjust for different size or shape axes.

Mountainsmith Fusion 35 Snow Sport Backpack REVIEW - 3
The tool sleeve on the left side is specifically designed for holding an ice axe. I found the side release buckle difficult to actuate because it is fixed to the sleeve. Hypalon reinforces the bottom edge to protect against wear.

Four Hypalon reinforced Velcro tabs, two on either side of the front pocket, attach two trekking poles. On the bottom of each side panel is a short “water bottle/wand” pocket made from the same fabric as the packbag. I found these pockets ill suited or unnecessary for either task. A water bottle of nearly any reasonable size won’t fit within, and the two pole tabs on the front make the need for a wand pocket unnecessary. Nevertheless, the presence of the “pockets” goes unnoticed and might be useful for carrying a fishing rod case or tent poles.

Mountainsmith Fusion 35 Snow Sport Backpack REVIEW - 4
Two Velcro straps on each side of the front pocket conveniently hold trekking/ski poles when not in use.

The tough stretch-woven fabric front pocket is large enough for a snow shovel and some additional gear. It is attached to the main body on three sides, with the opening on top, as we have become familiar with. The top is held secure with a side release buckle and strap going over the top of the pack. This strap is also useful for securing a climbing rope underneath the top pocket.

Mountainsmith Fusion 35 Snow Sport Backpack REVIEW - 5
The large stretch front pocket will hold a snow shovel for quick deployment. I kept the rest of my avalanche and first aid gear in the top lid pocket where it would be easily accessible.

The Mountainsmith Fusion 35 is a top loader with a fixed hood pocket. Being fixed, the hood pocket does not “float” to accommodate extra volume. There is an 8-inch extension collar and the hood will allow some increase in volume, but it tips forward rather than raising up. Mountainsmith topped the extension collar with double draw cords to make stuffing everything inside easier.

Inside, the Fusion 35 is similar to most top loaders, with a 3-liter hydration pocket and single exit port, but is fairly clean and cavernous otherwise. One unique feature is the use of a white polyurethane coating on the inside fabric. I found the white coating does make it easier to see the contents within by reflecting light, as Mountainsmith claims.

The top pocket also sports the new white coating and a key clip near the water resistant zipper (YKK #5) opening. Underneath the hood, you will find a clear view zippered map pocket. With skis or snowshoes attached, I had difficulty opening the top lid to see the map pocket underneath. The ski A-frame configuration narrowed across the top pocket, effectively pinching the pocket shut. The snowshoes blocked access to the side release buckle holding the top lid closed. Though abrasion is a concern, it might have proved more useful to place the map pocket on top of the top pocket.

Two other pockets are provided on either side of the hipbelt. The left one is a stretch-woven fabric with an elastic opening, perfect for holding an energy bar, but too insecure to hold anything of value. The right pocket is zippered, ideal for your backcountry permit, a small notebook and pencil, or a very small GPS unit (the Garmin Geko will barely fit). Neither of these pockets will accommodate even the smallest of digital cameras.

The fabrics used are more than durable enough for those of us who frequent the backcountry wearing packs of 1.1 oz/yd2 silnylon and spinnaker fabrics. The 210 denier and 420 denier nylon Cordura fabrics seem stiffer than past renditions of Cordura, and exude toughness. While soft powder will hardly scuff the surface, I also tested the Fusion 35 on day hikes and overnight backpacking, and found the fabric holds up well to the sandstone and cactus of the southwest. After four months and frequent trips, it is difficult to find much more than a scuff. The only durability issue was some slight fraying of the binding material used to frame the ice axe sleeve. The fraying occurs from the left lower trekking pole Velcro tab, which easily grabs the fabric. There are a few other places on the outside of the pack that use similar material to bind an otherwise raw fabric edge. The edge binding material is susceptible to snags at all of these places.

What's Unique

It can hold it all - skis, snowboard, snowshoes, crampons, ice axe, poles, avalanche gear, and enough food, water, and supplies - for a long day or hut-to-hut trip. The full-featured frame and suspension allow you to carry all your snow gear in comfort.

Recommendations for Improvement

We always harp about reducing the weight in this section. And for good reason; most of us are more than a little neurotic about lightweight gear. However, while the Fusion 35 won’t win any lightweight awards, snow sports packs need to be durable, and many of the extra features are desired by Mountainsmith’s mainstream buyers and won’t likely be stripped from the design. So my recommendation is not for Mountainsmith to reduce the weight, but for you to brandish a sharp pair of scissors to trim the excess. Food for thought: the few extraneous features, like the clear map pocket and Velcro strap keepers can be cut off with scissors, and the frame stay removed, to shave half a pound or more.

Mountainsmith should use a different material to bind the fabric edges. The material used is susceptible to abrasion and snags from encounters with Velcro.

Mountainsmith should consider increasing the volume of one of the hipbelt pockets to accommodate a small camera.

The Velcro strap keepers wreck havoc on lightweight clothing fabrics. I see this as a next frontier in pack innovation: to develop a means of containing straps without using Velcro. We all like the ability to strap items to the outside of our packs, but few find the dangling strap ends appealing.


"Mountainsmith Fusion 35 Backpack REVIEW," by Jay Ham. (ISSN 1537-0364)., 2006-02-12 03:00:00-07.