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Reviews > Packs > Internal and External Framed Backpacks > Columbia Mobex Backpack > Test Report by Matthew Mioduszewski

December 16, 2010



NAME: Matt Mioduszewski
EMAIL: Mattanuska AT gmail DOT com
AGE: 28
LOCATION: Portland, Oregon
HEIGHT: 5' 8" (1.73 m)
WEIGHT: 145 lb (65.80 kg)

I did small weekend trips growing up in Michigan. In 2007 I hiked most of the Appalachian Trail during a 5 month hike. I live in Portland, OR and frequently hike in the Columbia River Gorge and OR and WA, Cascades. I generally do day hikes, and weekend over nighters, with 5-15 lb (2.3 - 6.8 kg), but carry 25-30 lb (11.3 - 13.6 kg) on multi-day trips. I enjoy doing steep climbs, 2000-5000 ft (610 - 1524 m) over 1 to 4 miles (1.6 to 6.4 km) of distance. I have begun to do winter hiking with traction devices, snowshoeing, snow camping, and mountaineering in 2009.



Manufacturer: Columbia
Year of Manufacture: 2010
Manufacturer's Website:
MSRP: US $149
Listed Weight: No weight listed
Measured Weight: 2lb 7oz (1100g) measured
Other details: 22.5in x 10.5in x 7.75in (57.1cm x 26.6cm x 19.7cm)
Color: Black and grey

Columbia Mobex Winter XL is a winter version of the Mobex line. The mobex line uses a lightweight integrated external frame structure and utilizes full clamshell zip opening. The winter version modifies some the placement of some mesh pockets from external to internal, and has a shoulder strap modification to insulate an included 3 L bottom-opening water bladder manufactured by Hydrapak(r).


The Columbia Mobex Winter XL comes with some basic product tags that generically describe the "Omni-Heat thermal reflective" material and the stain and water repellency of the main pack fabric, "20D nylon Triple Rip Omni-Shield' (per Columbia's website). The fabric feels quite thin and lightweight. There are 4 lines of reflective piping along the front of the pack's wire frame.

The design of this pack looks unique! The most immediately noticeable feature of the Mobex Winter XL is the "Exo Flex" frame structure. It is a hybrid of external framing added to an internally framed pack. The thin, lightweight wires give the large day pack structure prior to being packed. The pack can be flattened but immediately springs back to shape.

Clam-shell Zip

The second most noticeable aspect of the pack is the large clamshell opening. There is a continuous zipper that runs the entire length of the pack from the bottom, to the top, and back down to the bottom on the opposite side. I have observed this design in other winter focused packs, as it allows one to open a pack and view the totality of packed items; juxtaposed with a top loading pack that would not allow access or viewing of items without removing that which is on top, or reaching down past them.


Digging into the first impressions, this pack has a plethora of pockets for a large day pack! There are four external zip pockets. Two are on the hip belt and there is one on both the top and a less noticeable one on the bottom of the pack. Internally there is a single removable zip pocket, and 4 elastic mesh pockets, in addition to the hydration sleeve. This brings the count to 9 pockets in total before the hydration reservoir pocket is accounted for. All zippered pockets have neat zipper pulls with a bit of rubber sleeve on them.

Internal zip and pockets

Additionally there is a mesh divider panel in the middle of the pack. This mesh divider is sewed into the bottom of the pack, but the top has hook and loop tabs which allow it to be secured to guy-points within the pack, to create a separated compartment.

There are four bungee attachment points along the external frame, which would allow for the storage of hiking poles, a lightweight tripod, or possibly an ice axe.

I was happily surprised by the inclusions of the liquid reservoir. This is a very soft rubber-like plastic with seal and folded opening, which allows the reservoir to be turned inside out for cleaning and drying.

Finally, the pack appears well made, with heavy duty stitching and reinforcement at stress points, without loose threads, and absent of any obvious defects. Zippers feel secure and strong. Mesh pockets seem well sewed and with an encouraging amount of elasticity.


The instructions for this pack are sparse to nonexistent. The tag that references the thermal shielding for the hydration tube makes mention of using a hand-warmer in a small mesh pocket to keep the hydration valve de-iced during extended duration winter activities. I may have used it as such when in the field, but would not have logically jumped to that conclusion upon first seeing it.
Hydration Tube Insulation

I wish there was a bit of instruction or documentation on their part to elucidate Columbia's product engineering and design thoughts. I would like to know why they have chosen the external "Exo Flex" frame and what advantages they promote with this design. It is definitely quite noticeable, but for my personal tastes I like to be told or sold on the functionality of a product, not just the design.


I have not had a chance to load the pack but an initial try-on yielded some observations and a few points to focus on.

An immediate and primary concern of mine was that this pack is uni-sized, meaning there is no specific sizing adjustment, it is a 'one size fits all'. I found I had to tighten the hip belt almost to the full extent of the available strap to get a secure fit. This yielded approximately 1.5ft (.45m) of dangling webbing from the hip belt. On a more positive note, the hip belt buckle is offset to the right, which should mitigate potential bulkiness of having a backpack buckle in the same place as a belt or integrated pants buckle.

The sternum strap on the Mobex Winter XL is extremely adjustable and easy to slide up or down. This is a much appreciated feature.

I felt slightly overwhelmed with the multitude of pockets, wondering if I would truly utilize all of them for functionality, or find myself attempting to make use of them simply due to their presence and the desire to utilize their space.


I plan on using this for day hikes and walk-up volcano climbs, and maybe attempting to use it for lightweight late summer, open bivy type excursions where minimal gear can be taken due to ideal conditions.

I will be gauging the use of the plethora of pockets, the mesh divider wall, and most importantly if I can discern specific advantages to the "Exo Flex" frame structure. I am curious to see how the structure influences the fit and feel when loaded with varying degrees of weight. I would also like to see if an ice axe can be safely secured using the bungee lash points on the frame.

Additionally I will evaluate the pack fabric, its water resistance and durability.

The Hydrapak is unique compared to other hydration bladders I have seen before. I will pay attention to the robustness of the material, potential leakage, ease of use, and susceptibility to retain smells or tastes.


Of primary focus, the Columbia Mobex Winter XL has a unique external "Exo Flex" frame. Secondly it has a full clam-shell zip. Additionally it has a lot of pockets, uses a very thin body fabric, and has some lashing bungees. Lastly it comes with a hydration bladder and a special insulated sleeve on the right shoulder strap.

This is a unique day pack that brings up lots of intriguing design questions, which I look forward to answering with functionality tests.



The Columbia Mobex Winter XL pack was tested on the North side of Mt. Hood during a sunny, dry, windy day. I hiked up Vista Ridge to the Barrett Spur and scrambled along the top of it. I estimate the temperature to have been between 60 - 75 F (15.5 - 23 C) gusting to 40mph (64km/h) at the top of Barrett Spur. This was approximately a 9 mile (14.5 km) day hike
Pack sitting upright

Pack with sit pad attached

I also tested the pack on foggy, drizzly day attempting to do the Whittier Traverse in Mt. Margaret Backcountry north of Mt. St. Helens. This day brought us temperatures between 40 - 50 F (4.4 - 10 C) with occasional gusts of wind, but otherwise mostly foggy conditions with occasional drizzle. Having not been on Whittier Ridge before, we turned around due to poor visibility in navigating further along the ridge, approximately 9 miles (14.5 km) into our trip, thus giving us a long 18 mile (29 km) trip.
Spirit Lake


I have a number of points to discuss about this pack:
1) Pockets
2) Uni-size Fit
3) Exoskeleton Clamshell Design
4) Hydration Pack

1) In preparing for two trips with the Mobex Winter XL pack, I was slightly overwhelmed with the amount of pockets available to put things in. I am a deliberate packer who sometimes spends an inordinate amount of time making sure things are very organized and meticulously packing my items to maximize available space. Between two hip belt pockets, a top and bottom external zip pocket, 4 internal elasticized mesh pockets, and an internal zip pocket, I truly felt there were more than I knew what to do with. That said I am aware that I often need to worry less about where things are and just get moving on the trail. I did find the internal mesh pockets helpful for stuffing gloves, a hat, headlamp, mini first aid kit, compass, and other items. The hip belt pockets are quite large and quite useful, capable of fitting my GPS, camera, pocket knife, chapstick, and any snacks easily. These pockets were great and should be considered essential. The internal hanging mesh zip pocket was helpful to put keys and/or ID into as I do like to secure those essentials in a place where they cannot accidentally fall out or be lost when accessing other items during a hike. Lastly, the external top zip and the bottom zip went unused. I found them too small and tight to fit a sunglass case in, and could not think of any other immediate use for them as they are not accessible while wearing the pack, thus negating their convenience when the hip belt pockets are of ample size to carry a wide range of desirable 'on the move' items.

One thing I found lacking is that I always carry a map and I do reference one often, even on known trails, just to reinforce my knowledge of the topography and what is visible around me. This pack provides no convenient method of storing a map, especially one that folds larger than would fit in a pocket. I found that to be a minor detriment, in light of the plethora of pockets otherwise available.

2) I was surprised by the uni-size fit of this pack. I tend to be between a Small and Medium in most gear sizing, from clothing to technical shells, to backpacks. I prefer to keep weight on my hips if I have that option, even with lighter loads such as those that would be in the Columbia Mobex Winter XL. The hip belt needs to be tightened to the point of only having approximately 2 inches of webbing left. I do like that the buckle is offset, with the left size being immediately on the left side of the hip belt padding. Also, as the hip belt is tightened the excess webbing can be tucked neatly under the right hip belt pocket, so it does not hang loose. I really like this aspect, as there are nearly 2 feet of excess webbing by the time I have tightened the hip belt to my liking. The same is true for the shoulder strap webbing, as there are elasticized bands that help to keep excess shoulder strap webbing from hanging down.

Overall the pack has carried well with 10 - 15lbs (4.5 - 6.8kg). I generally have found it to be comfortable but two areas have caught my attention as somewhat bothersome. I have felt the bottom of the pack push into my lower back/upper butt a bit, which could be related to how I like to have the majority of any pack weight solely on my hips. Secondly, I noticed that the shoulder straps irritated my neck on my second hike. The first hike I had a collared shirt on, and the second hike I wore a t-shirt. With the uni-size pack having a fixed torso size, when I have the hip belt at my prefer location, the top of the pack where the shoulder straps attach to it is approximately one inch above my shoulders. Additionally the shoulder straps attach to the top of the pack very close together which I think exacerbates this issue. I tried various adjustments but was not able to completely mitigate the chaffing I experienced while wearing a t-shirt. That said, I did not have an irritated neck when the hike was finished, so it was not too bad. I will continue to pay attention to it going forward.

3) I am still trying to determine the value of the exoskeleton clamshell design. The best I can determine is that it is a lightweight way for the pack to retain a structure when packing it. Indeed, having the clamshell zip instead of a top loading pack makes it easier to pack, view, and access one's gear.
Easy access to gear

I have found the 4 external bungee points to be useful for attaching a sitpad, poles, and ice ax (as a test). A short length of bungee cord could be tied between the external frame points in order to create a bungee back area capable of holding a jacket or other light-weight items.
Sit pad attached

The pack itself makes some creaking noises at times, but nothing more bothersome than other packs with well-defined frames. I did have some concerns about the way the omni-shield material is kept taut between the different sections of the pack when I was setting it down on sharp volcanic rock during my Mt. Hood Hike. The material seems strong, but when kept so taut, it seems like it is much more prone to puncture or ripping if it brushed against abrasive rock or brush, more so than a pack that has loose fabric, as it is not starting off stretched taut before additional force is put on it. The material also seemed to aptly repel the moisture and light sprinkles during my long hike in the Mt. Margaret backcountry. While I do not wish to hike in the rain, I am curious to see how it behaves in heavier rain and snow.

4) The water bladder that came with the Columbia Mobex Winter XL is among the best I have ever used. While it is a soft rubber-like material, in multiple uses in both the Mobex and other packs, it has proved to be remarkably durable, showing no signs of stretching, puncture, or scuffing. I love that the top can be opened to full size to allow snow or additional water to be easily poured in. Additionally due to the large opening, it can be turned inside out in order to clean it at the end of a trip. I am able to completely dry this hydration bladder in a matter of minutes, when others seem to never completely dry. However, the mouth-piece on this is substandard, both dripping fluid sometimes and being difficult to open and close. But, the ease of the bladder itself easily makes up for this shortfall. I also enjoy that the capacity is well over 3 liters and has detailed measurement marks up to the top. I have been unable to test the insulating properties of the shoulder strap integrated hydration sleeve, as it has not been used in below freezing temperatures.


The Columbia Mobex Winter XL Pack seems to be a pretty decent day pack or super ultralight backpack. The Uni-size allows it to fit a wide range of body sizes, and there are features to keep the shoulder and hip belt webbing neat. The Omni-shield material has some weather resistant properties, the hip belt pockets are of ample size for keeping desired items easily accessible while hiking, and the exoskeleton frame has enough attachment points for the minimum of desired external items (sit pad, ice axe, or trekking poles).

The included hydration bladder is of high quality and is a nice extra.


I look forward to continuing to use the Columbia Mobex Winter XL, especially as winter arrives in the cascades. I am hoping to use it during a day climb of one of the volcanoes, to test the ice axe attachment and the insulation properties of the hydration sleeve.



This pack was tested three additional times for the long-term testing. I used the Mobex Winter XL on a single day climb of Washington State's Mt. Adams during mid-October, an after-work nighttime snowshoe trip on Oregon's Mt. Hood, and on a short two mile (3.2 km) rainy hike along the Wilson River Trail in Oregon's Coast Range.

The conditions on Mt. Adams were sunny, chilly, and windy. Temperatures did not rise too much higher than 45 F (25 C) starting from a frosty low of 30 F (16.6 C) at 5AM that morning. Above treeline the winds were gusting. I estimate the winds at 15-25mph (24-40kph). However, the day's wind and cold was offset by plentiful sun. It was a longer day, approximately 11 hours, to do the 6680ft (2036 m) climb in a 12 mile (19km) round trip.
Top of Mt. Adams

The after-work nighttime snowshoe on Mt. Hood has become a fun tradition to do once a year after some snow has fallen on the mountain. As the sun sets by 5PM in the late fall, it was dark, about 28 F (15.5 C), with partially cloudy skies. There were occasional gusts of wind but it was otherwise calm.

Lastly, the hike along the Wilson River Trail was during a break in heavy rains. It was approximately 50 F (27.8 C) with sporadic heavy rain with light rain and misty conditions.


The Columbia Mobex Winter XL continued to perform well on the long-term test hikes. Three points were able to be tested and observed in greater detail.

1) The elastic loops on the outside of the pack hold an ice axe securely on the Mt. Adams climb. I kept the ice axe attached for most of the day. I noticed that as the day progressed, a fine dusting of volcanic dust accumulated on the pack. This seemed abrasive to the touch. I also felt I needed to be careful when setting the pack down on the jagged volcanic rock outcroppings at the "Lunch Counter", a broad semi-flat area midway up Mt. Adams. At the end of the day I noticed very faint abrasion in the area where the ice axe shaft was in contact with the pack, presumably due to the minor movement of the axe while I hiked. I believe the volcanic grit contributed to this. Wiping the pack with a damp paper towel cleaned the grit off it really easily.

2) The structure and Omni-Shield fabric performed well during snowshoeing. Without any open or mesh external pockets, in addition to having taut fabric, it shed snow very well. Some packs are liable to have snow accumulate in various creases and open areas, but not the Mobex Winter XL. The structured frame and the clamshell zip opening were helpful for accessing gear without having to empty the pack or sort around for items through a small opening. One concern I had was that if snowshoes were not needed, I would have to carry them, as there is no feasible method to attach such a large and heavy item to the Mobex.

3) The Omni-Shield fabric is much more water repellent than I anticipated. The design of the exoskeleton shell helps direct water off the pack. This functions similar to the way it does in the snow. The fabric being tight helped channel the rain and prevented pooling.

Additionally I have continued to be satisfied by the durability and usability of the included hydration bladder. While the hose valve is not perfect, I found the reservoir to be excellent for filling and drying. The fold-and-zip closure has been secure and not leaked. The rubber-like plastic has not retained any tastes or smells after filling it with Gatorade and flavored drinks, other than plain water. I am able to empty and dry this reservoir in a few minutes after a hike. This is a fantastic improvement over all my other water bladders.

Lastly I have still not found any use for the zippered pocket on the very bottom of the Mobex.


The Columbia Mobex Winter XL is uniquely constructed with an external exoskeleton-like frame. I feel this design functions at its best when used in snow and rain. The shell design helps to shed snow and water and the taut Omni-Shield fabric prevents pooling or accumulation. It was not until I used this pack in the rain and snow that the benefits of the exoskeleton frame became apparent. The structured design is moderately helpful when packing the backpack. The Omni-Shield material is lightweight, water-resistant, and in my testing, seems more robust than I anticipated.

I was pleasantly surprised by the fit for a uni-size backpack design. I am smaller in build and felt I could get a secure, and more importantly, comfortable fit. Based on strap lengths and the backpanel size, I am encouraged that it would fit a larger build.

The hip belt pockets are amply sized for most items that are convenient to have at hand, including snacks, GPS, camera, pocket knife, and chapstick. Those pockets not were quite big enough to put a map in, one minor area I found lacking. Beyond this, I found the pack to have a bit too many pockets for my liking. The 3 internal mesh pockets that use the exoskeleton and tautness to keep items secure were well designed.

The included water bladder design has been great and is a value-added feature.
Ice Axe Attached


I look forward to using the Columbia Mobex Winter XL for all-season day hikes and volcano snow climbs.

Thank you to BGT and Columbia for allowing me the wonderful opportunity to test this uniquely designed backpack!

This report was created with the Report Writer Version 1. Copyright 2010. All rights reserved.

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