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Reviews > Clothing > Jackets and Vests > Montane Flux Mens Jacket > Test Report by Brian Hartman

April 13, 2014



NAME: Brian Hartman
EMAIL: bhart1426ATyahooDOT com
AGE: 46
LOCATION: Westfield, Indiana
HEIGHT: 5' 9" (1.75 m)
WEIGHT: 145 lb (65.80 kg)

I have been backpacking for over 20 years throughout Indiana, Ohio, Kentucky and most recently in Western USA. In addition to backpacking I enjoy family camping with my wife and kids and being outdoors in general. I would describe myself as a mid weight backpacker. I use fairly light weight equipment and gear but still like to bring more than the bare essentials with me while on the trail.



Courtesy of Montane

Manufacturer: Montane
Year of Manufacture: 2013
Manufacturer's Website:
MSRP: 140.00; equates to $189 US
Listed Weight: 19.4 oz (550 g) Size Medium
Measured Weight: 19.1 oz (540 g) Size Small

Fabric: Pertex Microlight Rip-stop
Filling: Primaloft ECO 100g / 60g*
Lining: PEAQ Synthetic
Zips: YKK Vislon

Available Colors:
Steel / Burnt orange lining / Burnt orange zips
Alpine red / Graphite lining / Graphite zips
Moroccan blue / Graphite lining / Graphite zips
Black / Steel lining / Kiwi zips
Available sizes: S, M, L, XL, XXL

Features (as noted on manufacturer's hang tag):
Outer fabric Pertex Microlight Rip-stop that is completely windproof, showerproof, fast drying and features an exceptional durable water repellency
Dual density zoned Primaloft ECO insulation with internal baffle anchors: 100g Primaloft ECO insulation in the main body and arms, 60g Primaloft ECO in the hood
Chest pocket area features 60g Primaloft in front of and 100g behind, giving 160g in total
Inner hood, rear hem and pockets storm lined with Pertex Microlight Rip-stop
Articulated arms for reach high movement and tailored specifically to reduce hem lift
Fully adjustable helmet compatible mountain hood with three point adjustment and wired peak
Internal tab to lock down and roll away the hood in windy conditions
Two map-sized zipped Napoleon chest pockets
Internal security pocket
Two deep A-line hand-warmer pockets positioned well clear of backpack or climbing harness belt. Both pockets encased in Primaloft to help warm the hands
Full length, reversed and baffled two way YKK front zip for ease of use with a backpack or climbing harness
Easy sliding YKK Vislon zips throughout for use in icy conditions
Adjustable cuffs with grab tabs for ease of use with gloves or mitts
Adjustable hem to prevent spindrift entry and heat loss
Scotchlite reflective details for mountain safety
Stuffs into right hand pocket for easy storage

* This is a Primaloft trade name, conversions will be noted in the body of the report.


Chest pocket

The Montane Flux jacket (hereafter called Flux or jacket) is an insulated jacket with a DWR finish and non-removable hood, designed for cold, damp conditions. It is lightweight and very compressible, easily fitting into its own pocket stuff sack when not in use. Montane notes that "the Flux was conceived to be more than a simple belay jacket", incorporating maximum insulation without compromising comfort. The Flux features synthetic materials throughout including Pertex Microlight Rip-stop outer fabric and Primaloft ECO insulation. Pertex is a tightly woven nylon fabric that is windproof, showerproof and fast drying while still offering lightweight construction and excellent strength. The Primaloft insulation is 100% polyester and offers exceptional warmth (similar to 550 Down), water resistance and compressibility while still being lightweight, breathable and fast drying. For increased comfort Montane uses 100g (3.5 oz) Primaloft ECO insulation in the main body and arms and 60g (2.1 oz) Primaloft ECO in the hood. For additional warmth the chest pockets feature 60g (2.1 oz) Primaloft in front and 100g (3.5 oz) behind, for a total of 160g (5.6 oz).

The Flux has a full-length front zipper as well as four zippered outer pockets and one zippered inner pocket. The two outer chest pockets measure 10" x 5" (25 cm x 13 cm) while the two outer hand-warmer pockets measure 10" x 6" (25 cm x 15 cm). The inner chest pocket measures 10" x 6" (25 cm x 13 cm). The outer pockets are lined with Pertex and all of the zippers are YKK and have pull cords.

In addition to the features mentioned above, the Flux sports cuffs that are adjustable via hook-and-loop strips. The top 6" (15 cm) of the main front zipper is lined with fleece for extra comfort.

Also, the hood is fully adjustable and features a stiffened brim for increased visibility and to prevent sagging in downpours or heavy winds. Although the hood cannot be removed from the jacket, it can be rolled up and secured with an internal tab and hook and loop strap.

Inner pocket
Adjustable cuff
Rollaway hood

CARE INSTRUCTIONS: Montane provides care instructions for the Flux jacket on their website. Of note is that the Pertex outer fabric contains a Durable Water Repellency (DWR) coating and special cleaning instructions apply in order to maintain it.

Machine wash in warm water at 30C/86F with a mild detergent. Montane recommends that you use Nikwax Tech Wash.
Do not use fabric softeners or bleach.
Drip dry.
The jacket may need occasional re-proofing to restore the DWR. Montane recommends Nikwax TX Direct.

Finally the Flux jacket has a lifetime guarantee which protects it from faults in material or workmanship.


The Montane Flux arrived at my doorstep in excellent condition. The jacket is very well made and I couldn't find any blemishes, flaws or loose fabric threads. In fact Montane's workmanship and attention to detail was impeccable. I was also pleasantly surprised at how little the jacket weighed, given the fact that it is water resistant, fully insulated and hooded. Montane provided several nice color choices for this jacket and I especially like the steel exterior with orange lining and zippers (see photo to right). The pictures on their website also very closely depict the color I received. IMAGE 6

Montane describes the Flux jacket as having a Classic Mountain fit; after trying it on, I would describe the fit as athletic or tailored. I ordered a size small based on my chest and waist size and both jacket measurements were accurate with not a lot of room to spare. The arm pits and forearms of the jacket are snug even when wearing a single base layer. My recommendation would be to order up a size if wearing as an outer layer over base and mid layer clothing.

The combination of Pertex and Primaloft appears to be a great fit. The jacket drapes well and does not have all of the baffles and puffiness of a down jacket. Although Pertex is a tightly woven rip-stop fabric, it is so soft and supple that I'm wary of how it will hold up against briars and other sharp objects. For this reason, I will wear it mainly as a mid-layer with a shell overtop when breaking new trails this winter. I'm more comfortable using it as an outer layer while on trail although I am still anxious to see how well Pertex holds up to the constant wear and tear of backpack straps.

The pockets are roomy and quite warm. I can easily fit my hat, wallet or other items in the chest pockets and the pockets appear to be high enough so that they will be above my backpack belt.

The hood fits well and is easily adjustable. I'm really excited to finally have an insulated hood for those times when the wind is howling.

Although Montane describes the Flux as completely showerproof it does not have a storm flap, waterproof zippers or taped seams. As such, it will be interesting to see just how much rain the jacket can withstand before water begins to penetrate the Pertex shell. For now I have my fingers crossed because I really want to believe the claims.

Skies were clear and the temperature was 15 F (-9 C) this morning when I went outside for a walk with the Flux. The Flux went on very easily over a midweight long sleeve Capilene shirt I was wearing. At first I was cool due to the stiff breeze and temperature change from inside my house, but once I got going I warmed up quickly and the jacket did a good job of blocking wind from my body. The zippered pockets were easy to open and slid up and down smoothly and the hood was easy to put on and take off.


The Montane Flux jacket is well designed and constructed. I really like its large pockets and fully adjustable hood. It is lightweight, compressible and it seems like it will provide good warmth for me this winter. I am anxious to evaluate its waterproofness, if Mother Nature gives me the opportunity. I expect to use it quite often while backpacking during the next few months.

This concludes my Initial Report for the Montane Flux jacket. Please check back in approximately two months to learn the results of my Field Report. Thanks to Montane and for allowing me to test this jacket.



During the past two months I wore the Montane Flux on three backpacking trips. I also wore it to work, around town and while walking my dog around the neighborhood. In fact I pretty much wore it whenever I went outside, either as a mid layer or outer layer jacket. My first trip was a two day outing with my brothers to Oldenburg, Indiana (IN). The weather on this trip was overcast and cold with occasional snow and a nighttime low of 12 F (-11 C). My second outing was a two day backpacking night trip to the Hoosier National Forest in Southern Indiana where skies were partly sunny and there was 4 in (10cm) of snow on the ground. My third trip was an overnight camping trip where I hunkered down in subzero temperatures while 13 in (33 cm) of snow fell around me.

1. My first trip was to Oldenburg, Indiana (IN). During this two-day outing my brothers and I did some bushwhacking and also explored several frozen creeks. Daytime temperatures were in the mid 20's F (-3 C) and elevations ranged from 570 ft (174 m) to 780 ft (238 m).

IMAGE 1 Location: Oldenburg, IN
Type of Trip: Family camping
Distance: 4 mi (6 km)
Length of Trip: 1 night
Backpack Weight: 32 lb (15 kg)
Sky and Air Conditions: Overcast
Precipitation: 0.75 in (2 cm) snow
Temperature Range: 12 F to 26 F (-11 C to -3 C)

2. My second trip was to the Hoosier National Forest. During this two-day outing I hiked on and off trails covering approximately 8 miles (13 km) over moderately hilly terrain. Snow and slippery trails slowed my travels considerably. Elevations ranged from 505 ft (154 m) to 760 ft (232 m) and daytime temperatures were in the low 30's F (0 C).

Location: Hoosier National Forest
Type of Trip: Backpacking
Distance: 8 mi (13 km)
Length of Trip: 2 nights
Backpack Weight: 22 lb (10 kg)
Sky and Air Conditions: Partly sunny with light winds
Precipitation: None. 4 in (10 cm) of snow was already on the ground
Temperature Range: 32 F to 20F (1 C to -7 C)

3. My third trip was an overnight outing only a few miles from my home in Central Indiana due to a winter storm that was fast approaching. Because the weather reports called for heavy snowfall, subzero temperatures, and gusty winds I wore the Flux as an insulating mid layer and slipped a Gore-Tex shell over top of it. 13 in (33 cm) of snow fell overnight and temperatures dropped to -7 F (-21 C) with strong winds that reduced wind chills to -30 F (-35 C). Thankfully several large evergreen trees near my campsite protected me from the worst of the wind and snow until morning.

Location: Noblesville, Indiana (IN)
Type of Trip: Camping
Distance: 1.5 mi (2.4 km)
Length of Trip: 1 night
Backpack Weight: 26 lb (12 kg)
Sky and Air Conditions: Overcast with heavy snowfall followed by gusty winds
Precipitation: 13 in (33 cm) of snowfall
Temperature Range: 18 F to -7 F (-7 C to -21 C)


During the past two months of Field Testing the Montane Flux has performed exceptionally well in a variety of weather conditions including freezing temperatures with light snow, freezing temperatures with heavy snow and subzero temperatures with heavy snow and extreme wind. Did I mention it's been cold and snowy this winter? During this period I've worn the Flux as both a mid layer and outer layer jacket and it has proven to be warm, weather resistant and durable. On most of my trips I wore a mid weight synthetic top paired with a lightweight polyester pullover as my base layers and a Gore-Tex jacket, when needed, as my shell.

Warmth - So far all of my backpacking trips this test period have been in temperatures at or below freezing. In this weather the Flux did a good job of keeping my torso and arms warm as long as I was hiking aggressively. In temperatures below 20 F (-7 C), I found that I needed to wear a shell over top of the Flux to maintain warmth, regardless of how much I was exerting myself. I found the same was true at temperatures below 28 F (-2 C) when sitting around camp. At no time during my testing did I experience cold spots or areas where the insulation was too thin or had shifted. Since the hood is permanently attached and quite warm, I've found myself using it often. To date I haven't had the opportunity to test the high temperature rating for this jacket but it seems to have very good breathability so I am hopeful I can continue wearing it through most of spring and regulate my body temperature via the front zipper.

IMAGE 2 Weather Resistance - The Flux did a very good job of blocking wind and the adjustable sleeve cuffs and waist hem prevented cold air from chilling my arms and torso. The high front collar and insulated hood blocked a significant amount of wind from my face and neck and this too made a huge difference in how much heat I retained. When the snow started flying, and it did quite often, the Flux did a great job of shedding most of it. In all cases the Pertex shell and DWR coating gave me ample time to get out of the weather or put on my Gore-Tex shell. As an experiment, I went outside to shovel my driveway in heavy wet snowfall wearing only the Flux jacket with no shell and it took approximately 30 minutes before water started soaking through the jacket.

Ventilation / breathability - During Field Testing I did not encounter any temperatures too warm for this jacket, even when backpacking at a fast pace. The fact that it's fast drying, as witnessed by how quickly it dried out after shoveling my driveway in heavy snowfall, is an added bonus.

Comfort and fit - The Flux is soft and easy to slip on over my base layers due to its smooth interior surface but it is also snug fitting. It fits alright in the chest and waist but there is not much room at all in the forearms and arm pits. I noticed this most often when I was putting on my backpack or bending over to drive in tent stakes or clear an area for my tent site. My observation regarding its tight fit seems to be fairly well known based on what others have said on the net. I researched moving up a size but I don't think that would solve the problem as then the chest and waist would be too big and the sleeves would be too long. I wish Montane would relax their forearm and under arm measurements slightly as this would make wearing the Flux more comfortable. If air filtration is a concern, adding stretch bands to the waist and cuffs might solve that issue.

Durability - So far I have had no problems with durability. The seams have remained tight and there are no holes, tears, rips or even loose threads on the Flux. Despite trekking several days with a heavy backpack, the shoulder straps caused no noticeable wear on the jacket.

Features - The design of the Flux jacket is well thought out and it has performed well for me during the past two months of testing. The outer pockets on the Flux are well-placed and easy to access even while wearing a backpack. They were plenty large for anything I wanted to put in them and the insulated hand pockets provided a great place to warm up my hands after removing my gloves to light my backpacking stove. I had no problems with any of the zippers snagging or getting caught on the jacket fabric and they were easy enough to open and close while wearing gloves. It has taken me awhile to get used to the fact that the main front zipper pull is on the left hand side of the jacket. I still catch myself every once in a while holding onto the left side of my jacket when trying to open or close the zipper but it usually only takes a second before I realize my mistake.

Overall I am very happy with the Montane Flux jacket. It is warm, light weight, compressible, blocks wind and is water resistant. These four things make it a very versatile piece of clothing. So far I have had no issues with its durability and just need a change of weather to test its breathability.


So far I am very happy with the Montane Flux jacket. It is well designed, comfortable to wear, wind and water resistant and, so far, quite durable. Despite daily use the synthetic insulation shows no signs of breaking down and overall the jacket remains in great shape.

This concludes my Field Report for the Flux jacket. I will post my Long Term report in approximately two months so please check back for further information. Thanks to Montane and for allowing me to test this jacket.



Two night camping trip to Brown County, IN (Indiana). I hiked 9 mi (14.5 km) in temperatures ranging from 18 - 24 F (-8 to -4 C).

Two day / two night backpacking trip to Monroe County, IN. While in the Bloomington area I hiked 12 mi (19 km) on snow covered trails. The temperature was 24 F (-4 C) on the first day but dropped to 15 F (-9 C) the following morning as colder air moved in.

Ski trip to Perfect North Ski Resort in Lawrenceburg, IN. Skies were mostly cloudy and the temperature stayed right around 20 F (-7 C) most of the day.

Day hike at MacGregor Park - Westfield, IN. While at this park, I hiked approximately 3.5 mi (5.6 km) over hard, frozen trails with gently rolling terrain. The temperature stayed just below freezing at 30 F (-1 C) while skies were sunny.


Temperatures during the past two months were below normal with daytime highs ranging from the teens (-9 C) to mid 20 F's (-3 F), until recently. During this time I wore the Flux as both a mid and outer layer depending on my activity level and the wind chill factor.

WARMTH: I have been really impressed with the performance characteristics of this jacket. The Primaloft ECO synthetic insulation has proven to be extremely warm for its weight and quick drying when wet. It is also super lightweight and compressible into a tiny ball for storage. When worn as a mid layer on my ski trip to Perfect North, the Flux kept me plenty warm and dry as I (unintentionally) slid on my front and backside down the slopes. When worn as an outer layer while backpacking in Monroe County, its high loft kept me warm and dry even though the outer shell soaked through after an hour or so of heavy snowfall. These experiences as well as another one I mention below confirm for me Primaloft's ability to retain its loft when wet thus keeping me warm in cold wet weather conditions. For its warmth to weight ratio, quick drying characteristics, super light weight, compressibility and reasonable cost, I prefer Primaloft to all other insulations for cold wet conditions like those experienced in the Midwest during winter.

I never used to wear hoods but Montane has made me a convert. During cold windy weather the hood on the Flux jacket has been a godsend. It not only adds significant warmth to my core but also provides great protection from the elements.

DURABILITY: In regards to durability the Flux has held up very well despite my nearly daily use during the past two months. There are no wear spots on the shoulders or waist from my pack straps and I've had no issues with the zippers, although I still find myself fumbling with the front zip; darn left hand zipper. Despite its durability I'm still careful not to put the Flux in precarious situations such as walking thru briars etc. I have also not washed the jacket yet (hey, it doesn't smell) so I can't speak to how it will hold up in the washer.

In addition to backpacking and skiing I wore the jacket around town every chance I got. Most recently I wore it while biking in 38 F (3 C) weather. The Flux was so good at retaining my body heat that I started sweating within the first 10 minutes of my ride. Not wanting to stop and remove the jacket as I was only wearing a T shirt underneath, I opened the main zip to try to cool down. The breeze helped evaporate moisture from my chest area but did nothing for my back and arms which were literally dripping in sweat by the time I got home. What I took away from this experience was that although the Flux is great at blocking wind and preventing air from circulating through the jacket it can't release loads of moisture all at once. I'm pretty sure most windproof insulated jackets would have failed this test. My point in mentioning this incident is that despite being soaking wet, the Flux kept me warm not only during my ride but afterwards while I cooled down and let the jacket dry out.


The Montane Flux performed very well this winter. It handled single digit temperatures, wet snow and high winds while keeping me warm and dry. It has been fun to wear throughout this test period and I look forward to wearing it for many more years.

This concludes this test series. Thanks to Montane and for the opportunity to test this jacket.

Extremely lightweight
Very Compressible
Sufficiently warm for three season (excluding summer) pursuits
Good wind resistance
Continues to insulate when wet

Snug fitting in general but even more so in the forearms and armpits
Not extremely breathable

This report was created with the Report Writer Version 1. Copyright 2014. All rights reserved.
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