A synthetic-fill, full-zip jacket with highly breathable stretch panels and thumb-hole wrist sleeves
Overall Rating: Recommended
This jacket wears like a wind resistant fleece jacket, but benefits from the lighter weight:warmth relationship of the synthetic fill. There are lighter weight jackets better suited to lightweight backpacking, but these lack the closer fit and mobility one might want when pursuing a highly mobile activity such as backcountry skiing, trail running, or mountain biking. Few jackets on the market can compete with the features, weight, and versatility of MontBell's U.L. Thermawrap Action Jacket.
MontBell's Ultralight Thermawrap Action Jacket combines the loft and wind resistence of synthetic fill with the higher breathability of stretch fleece side panels to produce a jacket better suited to high octane pursuits. This is a close fitting jacket best suited to above freezing temperatures or layering under heavier insulation. I tested the 10.2 ounce (size M) MontBell Action Jacket while mountain biking, trail running, cross-country skiing, and backpacking through the colder months in northern Arizona (>7000 feet elevations).
This jacket received a major improvement in 2006. Previous versions of the Action Jacket used a YKK Conceal main front zipper (and actually included an instruction card on how to use them). Conceal zippers are aesthetically pleasing, as the zipper teeth disappear when zipped up. However, these zippers were difficult to operate, especially while wearing gloves, and were a source of complaints from users. Specifically, they are difficult to get started when trying to connect the two separating parts.
In 2006, the Conceal zippers were replaced with smooth-operating, standard YKK coil zippers. Having used both types, the new coil zippers are much appreciated. The two hand-warmer pockets still have Conceal zippers, but since these are permanently together (non-separating) they don't have the same problem as the previous main zipper.
The Thermawrap Action Jacket uses 50 gram/m2 Exceloft insulation. In my experience, MontBell's propriety Exceloft insulation performs similarly to Polarguard or Primaloft in jackets of similar loft. The Action jacket takes a fair amount of rain or snow before wetting through (partial thanks to the DWR coating), maintains warmth when wet, and dries quickly. The 15-denier Ballistic nylon shell material held up well to light abuse; no rips or snags after 8 months of use.
The MontBell Thermawrap Action Jacket is a trim fit (author is 5'7" and 160 pounds, size medium tested). It layers well over a single long-sleeve base layer, and easily layers underneath additional layers of insulation or a trim rain jacket. The side stretch panels provide this trim fitting garment with plenty of stretch and freedom of movement. The stretch fleece enhanced breathability as well; they extend down the sleeves nearly to the elbows.
MontBell offsets the trim fit of their U.L. Thermawrap Action Jacket with highly breathable, stretch fleece side panels (modeled by my daughter, Ivy Ham).
Another unique feature not often found in a synthetic fill jacket, MontBell added stretch fleece cuffs with thumb holes. The thumb holes are really handy on short running or cross-country ski trips. They keep my knuckles warm and can be removed (pushed up) without having to stow them. The stretch material does show wear over time. It tends to pill ball, and the inside seams on my jacket have started to fray a bit. This is cosmetic; pill balls can be pulled off, and I have carefully seared the edges inside the sleeves to prevent them from further fraying. My other concern is with the thumb hole's size. They are a little tight for my size L hands, but not uncomfortably so.
The stretch fleece sleeves have thumb holes and length enough to use them. The fleece started to pill ball slightly after extended use (modeled by my daughter, Elly Ham).
Draft control is handled by a non-adjustable lycra waist line. The main zipper blocks wind entry with an inside storm flap. The storm flap is protected with a strip of grosgrain to keep the zipper from snagging.
Features and Specifications
Model: MontBell U.L. Thermawrap Action Jacket
Weight: 10.2 ounces (289 grams), size medium weighed