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Mammut Flexidown Jacket looks as good in the city as it does on the slopes

Mammut Flexidown Jacket
Mammut Flexidown Jacket
Steve Mullen

Mammut Flexidown Jacket


The Mammut Flexidown Jacket, with its slim, modern design and comforting warmth, provides an insulating layer under a shell or ski jacket, but is stylish enough to stand on its own. Filled with a thin layer of goose down, the jacket features stretchy side panels that allow freedom of movement and a minimum of bulk.

Mammut Flexidown Jacket

If you live in the tropics or a desert and didn’t feel the cold this winter you might have missed the latest feather down trend, the omnipresent slim-profile, lightweight jackets, sometimes referred to as down sweaters or even down shirts, that everyone seemed to be wearing . Wherever crowds of people were found one could find a sea of puffy down in a rainbow of colors and mostly indistinct styles with a front zipper, two side zip pockets, a collar and no hood. The Flexidown Jacket takes its place in the mob but with some distinctive touches that sets it apart. First, the slim, anatomical fit—no shapeless straight sides here; this jacket hugs curves like a glove. Second, the side pockets are invisible save for the zip pull in a contrasting color that provides a distinctive accent. Third, the large box-shaped baffles offer cleaner lines than the typical horizontal rows of baffles. Fourth, the stretchy side panels provide extra ventilation, a slimmer fit and more flexibility than an all-down jacket.

Several trends that have building over the last few years are coming together at once. The ultralight movement, combined with increasing prices for feather down and a reaffirmation of the benefits of natural fibers, has led to a resurgence in popularity for down, wool and cotton, all natural products that have stood the test of time. In the case of down, which is sourced mostly from Asia as a side product of food produced from ducks, the volume is down significantly due to the rise of the middle class who are now able to procure other forms of protein for food, such as beef. At the same time outdoor enthusiasts have been trending toward a preference for lightweight, yet effective, gear. Retailers have responded by creating apparel with smaller amounts of down resulting in trendy jackets that can be worn to ward off a slight chill and be layered under outer shells, unlike the big, poofy down jackets of the past that would have been too warm except in the most extreme cold.

I tested the Mammut Flexidown Jacket over the past few winter months, transitioning into spring, and found it to be quite versatile. I expected it to travel well and keep me warm but was pleasantly surprised at how tasteful the black jacket was on a trip to Vancouver, a chic, modern city with bone chilling, damp winters. It packed down to nothing and was perfect to throw on for a stroll around downtown in search of a steaming hot latte. I appreciated the fabric side panels that breathe more than an all-down jacket when I was in and out of buildings as I didn’t overheat. However, on a longer trek through Stanley Park, I did get a bit chilled when the wind picked up and could tell I was losing body heat through those side panels. I always have to pack warmer ski clothing for Whistler than my usual gear in California and appreciated the slim line of the side panels when donning an outer shell over the Flexidown Jacket. The combination of down with a heavier, outer shell was a winning arrangement to protect me from the frosty Canadian winter temperatures, and the side panels made the system feel compact and unconstricting. Back at home in California, where the daffodils heralded the start of spring, I pressed the Flexidown Jacket into service at casual social events and consistently received compliments and questions about the style and construction because people could tell there was something a little different about this jacket.

The outside material, Pertex Microlight, is a lightweight, breathable nylon that is downproof and windproof. The jacket is a good insulator with 750 cubic inches of fill and 90% down (10% feathers). It comes in two colors, sophisticated black and imperial blue. At 11 ounces it satisfies the most discerning ultralighter.

Mammut, based in Switzerland, has roots in the outdoor industry stretching back to 1862, when Kaspar Tanner launched a mountaineering ropes company. Evolving from a small, traditional family business to a global company they are still a leader in manufacturing ropes, which are still Swiss-made. Along the way they acquired well-known brands such as Raichle (mountaineering boots and trekking shoes), Toko (ski wax) and Ajungilak (sleeping bags) to round out their portfolio of outdoor products. They offer a wide range of apparel and other products, including fleece and down jackets, specialized shorts and pants that integrate a climbing harness, and rappel kits. In addition to manufacturing quality products, they offer an Alpine School at several locations in Europe for those who want to learn mountaineering, rock climbing and glacier travel skills.

Pros: The Fexidown Jacket is attractive due to the athletic cut and fashionable accents while the feather down provides good warmth in cool temperatures. The construction is of the highest quality and the side panels provide less bulk and more freedom of movement than traditional jackets.

Cons: The side panels do allow some heat to escape, which, when the temperatures are low and the jacket is worn on its own, can result in a drafty feeling under the arms. It’s best to pair it with an outer shell in very cold weather or high wind.

The Mammut Flexidown Jacket, filled with a soft layer of goose down, is warm and chic but is rugged enough to put to work in the winter, by itself or under an outer shell. In spring and fall it can stand on its own as a lightweight jacket to ward off the chill of changing seasons.

Product Information:
Mammut Flexidown Jacket, available in both men's and women's sizes
Retails for about $250 (on sale as low as $149)

Disclosure of material connection: I received a test sample from Mammut but the opinions expressed are solely my own.