The Montane Minimus 777 jacket is a lightweight, 3-layer waterproof/breathable shell that weighs just 5.1 ounces (144 grams) in a men’s XL, making it lightweight enough to be used as a rain jacket and wind shirt when you want one garment that can perform both functions. Designed for high activity sports like hiking and trail running when you are generating a lot of body heat, the Minimus 777 has a very thin shell fabric that improves its breathability because moisture has to pass through a thinner barrier. Highly compressible and packable, the Minimus 777 virtually disappears in a backpack, making it a good ultralight backpacking gear choice.
The Minimus 777 is a 3-layer waterproof/breathable shell made with a 7 denier nylon face fabric, a 7 micron Pertex Shield+ laminate, and a 7 denier tricot backing that helps improve the jacket’s durability. All of the interior seams on the jacket are seam-taped to ensure waterproofness. A DWR coating is applied to the exterior of the jacket to bead precipitation so it runs off the surface of the jacket.
The manufacturer claims that the Minimus 777 is waterproof with a 20,000mm hydrostatic head and that it has a MVTR rating of over 30,000g/m2/24hrs.
The Minimus 777 has a simple hood, although it is sized for hikers and trail runners, not skiers or climbers wearing a helmet. While not adjustable, the hood has a piece of elastic in back and around the front opening that helps mold it to your head and face (even if you have a small head like mine.) The hood also has a small front brim, although it does not contain a shaping wire, necessitating a brimmed hat if you want to keep rain out of your face.
There’s a left side front pocket, large enough for a pair of softshell gloves or GPS/Smartphone, which doubles as a stuff sack when you want to store the jacket. It has a YKK Aquaguard water-resistant zipper, which is also used for the main zipper on the jacket. The main jacket zipper is also backed with a storm flap.
The wrists of the jacket are elasticized, but fairly snug so you can’t pull them up higher than your forearm. The hem is also elasticized. The jacket length drops to the bottom of the buttocks but tends to ride at waist height when worn with a backpack.
I tested the Montane Minimus 777 over a two month period in New Hampshire’s White Mountains in temperatures ranging from 70 degrees down to 30 degrees in rain, snow, and windy conditions, above and below treeline.
The breathability of the Minimus 777 is superb and it is certainly one of the most breathable rain jackets I’ve ever tested. I attribute its breathability to the thinness of the jacket’s fabric. The jacket also keeps me much cooler than other rain or alpine shells, resulting in less perspiration. This is most noticeable during periods of heavy exertion, such as climbing uphill.
While this is advantageous in warmer temperatures, the Minimus 777 requires careful layering when temperatures drop because it does not retain much body heat. I do not plan to use it for full-on winter hiking for this reason and will switch to a thicker, warmer alpine shell with better ventilation, an adjustable hood, and more pockets for colder, above treeline hiking/mountaineering.
The packability of the Minimus 777 is also superb. While you can stuff it in its pocket, I pack it loose in my backpack since it takes up little space and the fabric is so thin, soft, and malleable.
While the factory DWR coating is very good, I have noticed wet-out under my backpack shoulder straps which is what you’d expect from any waterproof/breathable jacket with a DWR coating.If you purchase a waterproof/breathable jacket that has a DWR coating, it will be necessary to reproof it periodically to restore its performance.
The front pocket also collects considerable moisture, passed from inside the jacket, and will dampen gloves, hats, or electronic devices stored in it. If you have a smartphone, I’d advise storing it in a waterproof protective case or elsewhere in your backpack.
If you are looking for a very lightweight waterproof/breathable rain shell, particularly for three-season hiking or trail running, I recommend the Montane Minimus 777 jacket, which is also available as a pull-on. Usable as a rain jacket or a wind shell, the Minimus 777 weighs just 5.1 ounces (144 grams), packs up very small, and provides best-in-class breathability. The fit is snug as is the UK hill-walker style, so be prepared to try on different sizes to dial in the jacket size you need to accommodate your mid-layer clothing system.
Disclosure: Montane provided Philip Werner with a sample Minimus 777 jacket for this review.