The Marmot Reactor is the fleece for the dirtbag adventurer who needs a warm, simple mid-layer without excess features. We tested each model with comfort, breathability, and layering ability in mind, as these are our main concerns when shopping for a fleece jacket. The Reactor comes through strong in each of these metrics by providing a solid fit and wicking when hot. In addition, this model's sizing provides you with the ability to wear jackets under and over it.Editor's Note: On August 26, 2022, we added the Reactor 2.0 to our line up.
Marmot Reactor 2.0 Review
Cons: Lower warmth, no hood
Compare to Similar Products
Marmot Reactor 2.0
$62.97 at Backcountry
$98.99 at Amazon
|Check Price at REI|
Compare at 2 sellers
$49.95 at REI
|$27.93 at REI|
Compare at 3 sellers
|Pros||Lightweight, easy to layer, breathable, drawstring hem||High performance, solid fit, breathable, solid features||Breathable, lightweight, inexpensive, comfortable for athletics||Inexpensive, cozy, great stand-alone jacket||Inexpensive, packs away easily, casual look for around-town use|
|Cons||Lower warmth, no hood||Difficult to add many layers under, not as warm as other models||Average weather resistance||Bulky and lacks breathability, hard to layer under tight layers||Poor warmth-to-weight ratio, bulky, not the best for layering|
|Bottom Line||This simple fleece is breathable and layers well, all for an excellent price||Built for the athlete, this model provides warmth, as well as a highly functional piece||Highly featured and even higher performing, this cost-effective option provides a hard-to-beat value||An inexpensive fleece jacket with a simple non-technical design and a bit of comfort||It's basic and heavier weight, but still maintains the creature comforts, and is soft and affordable|
|Rating Categories||Marmot Reactor 2.0||Mountain Hardwear S...||Outdoor Research Vi...||REI Co-op Groundbre...||Columbia Steens Mou...|
|Layering Ability (15%)|
|Weather resistance (10%)|
|Specs||Marmot Reactor 2.0||Mountain Hardwear S...||Outdoor Research Vi...||REI Co-op Groundbre...||Columbia Steens Mou...|
|Measured Weight||10.9 oz||13.3 oz||13 oz||11.6 oz||16.6 oz|
|Main Material||100% polyester||100% polyester||94% polyester, 6% spandex||100% polyester||100% polyester|
|# of Pockets||3||2||3||2||2|
|Unique Features||Windflap with roll-over chin guard, flatlock seams||Raglan sleeves, thumb holes, three-piece fitted hood||Thumb holes, UPF 30, 3-panel hood with binding||Stretch binding at waist and cuffs||None|
Our Analysis and Test Results
A simple, well-designed fleece made of Polartec Classic 100, which is 100 percent polyester microfleece, the Marmot Reactor 2.0 features flat lock stitching, which adds comfort and dexterity. Its regular fit works well for different body types and the jacket has two zippered handwarmer pockets along with a zippered left arm pocket. The elastic drawcord hem allows the wearer to adjust the amount of airflow and temperature quite easily. The flap behind the zipper blocks out the wind and also attaches to a chin guard for added comfort.
This fleece is so light that it left our testers surprised that it felt so warm. For the weight, it is an excellent insulator and a great piece for chilly mornings. Throw the Reactor in your pack and forget about it once the day starts to heat up or carry it into the mountains where you never know what the weather might throw at you. While this jacket isn't the warmest fleece we tested, we don't think you'll find anything much warmer with the same weight and thickness.
The Reactor scores well in the comfort metric. Against our skin, the Polartec Classic Micro 100 fabric feels soft and cozy. We wouldn't think twice about wearing this jacket through the night for a little extra warmth in a sleeping bag. The cut is athletic with a generous amount of stretch, so it never felt too tight, even on our broader-shouldered testers.
The collar zips up just underneath the chin and feels warm against the neck without being too tight or restricting movement. The cuffs are a bit loose, which is excellent for those who like to pull their sleeves up past their elbows, but not so good for moving around underneath other layers. We weren't thrilled about the elastic drawstring around the hem of this jacket. It causes the zipper to bunch up, and when pulled tight, the whole hem rides up.
Since the Reactor is so thin, it breathes fairly well. We wore it on big hikes out of the Owens River Gorge in Bishop California and around the Flatirons of Boulder. While we of course worked up a sweat, it did a good job of moving moisture from the body and drying quickly.
On its own, the Reactor can only handle light-duty conditions, but underneath a shell, it insulates wonderfully as a mid-layer. The athletic cut lends itself well to sliding into a shell or underneath a puffy jacket. While we prefer jackets with hoods, the lack of such a luxury on this fleece makes for better layering, since it doesn't bunch up the hoods on other layers. We do wish this model had thumb loops, as they would keep the sleeves in place when putting on additional layers; another solution is tighter fitting cuffs.
No fleece is expected to hold up against heavy conditions like rain or snow since they are primarily designed to insulate. However, it's nice to know how a fleece performs as a standalone piece against the elements. Like the majority of the jackets in this selection, the wind cuts through the Reactor. Fortunately, due to its layering ability, it fits well under a light wind layer. This jacket fares better against the rain than most fleece jackets, repelling mist and very light rain. When the precip ramps up to anything more than a drizzle, you'll want to put on a hardshell or a rain jacket.
Slim and trim, this jacket weighs in at approximately 10.9 ounces. While there aren't any bells and whistles or a hood on this jacket, its insulating capabilities are hard to beat. Its warmth-to-weight ratio is excellent, especially considering the price, and it easily snags our Best Buy Award.
Should You Buy Marmot Reactor?
For cool hiking conditions in early spring and late fall, this jacket is a worthy choice. The shorter cut and the location of the handwarmer pockets don't make it ideal for climbing, but we'd use it in a pinch, as the stretch doesn't restrict movement. If you're on the hunt for a good value, check out this fleece. Though there are less expensive choices, they don't perform as well. The Reactor is still half the price of the most expensive jacket in this review, and it's got the goods. It'll keep you warm, breathes well, and layers like a champ.
What Other Fleece Jackets Should You Consider?
The Marmot Reactor is ideal when worn under a shell on a gloriously sunny spring day at the ski resort. The price of this jacket makes it a good choice. However, the Outdoor Research Vigor costs even less and offers a higher level of performance. It's great for layering purposes and it's more breathable than the Reactor.
— James Lucas
Ad-free. Influence-free. Powered by Testing.
GearLab is founded on the principle of honest, objective, reviews. Our experts test thousands of products each year using thoughtful test plans that bring out key performance differences between competing products. And, to assure complete independence, we buy all the products we test ourselves. No cherry-picked units sent by manufacturers. No sponsored content. No ads. Just real, honest, side-by-side testing and comparison.Learn More