The Montbell Thunderhead Jacket is made of Gore-Tex Pro Shell and PacLite fabrics, weighs 12 ounces, and costs "only" $298. Photo by Bill Webbe
Following the announcement of Gore-Tex Pro Shell fabric in spring 2007, numerous manufacturers are getting their Pro Shell products to market this winter and spring. Among the lightest of the crop is Montbell's new Thunderhead Jacket, scheduled for spring 2008 availability. Montbell's version of Pro Shell is a thinner 30 denier 3-layer construction, with shoulder panels of 20 denier Gore-Tex PackLite to save some weight and cost. At $298 US, the Thunderhead is comparatively inexpensive, though that's still a chunk of change.
A full discussion of the merits of Gore-Tex Pro Shell versus eVENT fabrics is beyond the scope of this review (although it's awfully tempting!). Backpacking Light has addressed this issue elsewhere, and the short answer: if you want fabric breathability, go with eVENT. Comparative measurements of fabric breathability by the US Army and numerous apparel manufacturers have confirmed that beyond a doubt.
The bottom line question to be addressed here, in Backpacking Light's first test of the Pro Shell fabrice: does Montbell's thin Pro Shell fabric construction in the Thunderhead jacket, in combination with pit zips and a full front zipper, allow its performance to be comparable to a typical eVENT jacket?
Montbell has a reputation for creating very lightweight outdoor gear and has consistently introduced new products that get our attention. The Thunderhead jacket is remarkably well thought out, with an essential feature set (listed at the bottom of this review) to satisfy most hikers, but no extra bells and whistles.
With 12-inch pit zips and a full front zipper, the Montbell Thunderhead Jacket has good ventilation.
Over a four-month period, I tested the Thunderhead jacket on a total of twenty-three trips, including an eleven-day winter camping trip in Yellowstone National Park. I got thoroughly familiar with it in all kinds of conditions and occasionally tested it side by side with an eVENT jacket.
In weight class, the Thunderhead is comparable with the lightest eVENT jackets. For example, the Integral Designs Thru Hiker Jacket weighs 11.9 ounces in size medium, but the Thunderhead includes two side pockets and pit zips for the same weight. I found the Thunderhead's side pockets to be very useful for stashing lots of smaller gear items to keep them handy, and they are set high, so they are not covered up by a hipbelt. I would personally like to see a pair of drop pockets added to the inside of the jacket, like those on Montbell's Alpine Light Down Jacket.
Although the Thunderhead is made of thinner fabrics, I found it to be adequately durable for general use without babying it. On many occasions I clipped branch stubs while backcountry skiing, snowshoeing, or hiking and there was no damage to the jacket.
In performance, the Thunderhead is a genuine competitor to other lightweight hardshell jackets. For one thing, its 30 and 20 denier fabrics are more supple (less stiff) than many other jackets, including eVENT, which makes it more comfortable to wear. Plus, it remains suppler in sub-zero temperatures compared to other hardshell jackets I have worn.
The Thunderhead's hood has one drawcord adjustor and one Velcro adjustor on the back, which do a good job of securing the hood in a wind and snowstorm, and protecting without obstructing vision to the side. Photo by Bill Webbe
I found that I routinely wore the Thunderhead over one or two baselayers as my standard torsowear for hiking and snow sports in cool and cold weather, and over a synthetic insulating layer in really cold weather. In warm weather hiking, I used it only for windy or rainy conditions. By opening the pit zips and front zipper, I was able to maintain my comfort level very well.
The Thunderhead jacket is comfortable to wear over a single baselayer when actively snowshoeing or hiking. I usually kept the front zipper and pit zips open for ventilation.
In my comparisons with an eVENT jacket (Rab Drillium), I wore the jackets (over a single wool baselayer) successively while hiking uphill carrying a loaded backpack in cool weather (25-30 °F). Frankly, I didn't notice much difference - after about a half hour of hiking, it got steamy inside of both jackets. I opened the front zipper as much as I could on both jackets to try to maintain comfort, and opening the pit zips on the Thunderhead helped to make its performance comparable with the eVENT jacket, which lacked pit zips. The bottom line is that it's hard to wear any shell jacket, including an eVENT jacket, while vigorously hiking uphill while carrying a backpack, unless it's cool, overcast, or windy.
Supplemental ventilation is more important while wearing a Gore-Tex jacket than it is with an eVENT jacket, and I utilized the pit zips and front zipper a lot while wearing the Thunderhead jacket. In my opinion, the supplemental ventilation made the Thunderhead roughly equivalent to an eVENT jacket. So, would I choose the Thunderhead over an eVENT jacket? Not necessarily. I would opt for the Integral Designs Thru Hiker jacket (or eVENT Rain Jacket if the short torso is acceptable), because of its lower price (it's $38 cheaper), and simple, well-fitting hood.
After four months of heavy use (and no washings), the Thunderhead Jacket lost a lot of its water-repellency. In this photo, taken after an hour of hiking in the rain, the face fabric has wetted out, but water has not soaked through to the interior of the jacket.
A key point I want to make in this review is that the Montbell Thunderhead jacket is a very well-designed, lightweight, and functional jacket that will perform (with supplemental ventilation) comparably with an eVENT jacket. If you prefer Gore-Tex, the Montbell Thunderhead is an excellent choice and a good value.
Specifications and Features
- Manufacturer: Montbell (http://montbell.com/)
- Year/Model: 2008 Thunderhead Jacket
- Fabrics:: Body is 30 d 3-layer Gore-Tex Pro Shell, shoulders and upper arms are 20 d Gore-Tex PacLite
- Features: Attached hood with drawcord and Velcro adjustors in back, waterproof zippers, twelve-inch pit zips, two zippered front pockets, full height front zipper, hem drawcord with one adjustor, Velcro cuff adjustors
- Weight: Men's Medium measured weight 12 oz (340 g), manufacturer specification 12.1 oz (343 g)
- MSRP: $298 US