Montbell Thermawrap Pant on an early summer mountain backpacking trip. The temperature was 30 F.
The Montbell Thermawrap Pant is a full-featured, lightweight, synthetic insulated pant. It packs a lot of features and warmth into its eleven ounce weight (size large), making it a highly versatile piece for year-around use. In comparison, the Bozeman Mountain Works Cocoon UL 60 Pant is a simple pull-on with few features and more insulation, and weighs 3.6 ounces less. The issue I would like to address in this review of the Thermawrap is whether the features are worth the extra weight.
Look at the list of features in the Specifications section below; Montbell has masterfully incorporated a lot of features into the Thermawrap Pant while keeping weight to a minimum. The key issue is whether or not you want or need all of these features, compared to keeping it simple and light.
I selected the Thermawrap Pant to use on an eleven-day winter camping trip in Yellowstone National Park, where we build three different igloo base camps and skied the surrounding areas. My legwear clothing system consisted of thin wool long johns (Ibex Woolies), an insulation layer (Montbell Thermawrap), and a shell layer (Rab Bergen Pant). I typically wore the wool long johns and eVENT Bergen Pant for daytime winter travel, and my plan for extra warmth on very cold or windy days was to add the Thermawrap Pant without having to take my boots off. It worked perfectly, thanks to the full length side zippers on the Thermawrap. In our igloos at night, I wore all three layers.
Beyond using the Thermawrap on our Yellowstone odyssey, I wore it as a midlayer on several backcounty skiing trips at high elevations and cold temperatures and found it to be very warm and versatile. When I heated up while climbing with skins, I opened the side zips for extra ventilation, and closed them on descents to keep the snow out.
As winter gave way to spring and summer, I wore the Thermawrap as leg insulation in camp and in my ultralight sleeping bag. When I donned them for camping insulation, I found the zippered hand pockets to be useful for keeping things handy, but the full-length leg zips were not needed. I also liked the zippered fly. Especially notable is the Thermawrap Pant fits very well, at least for me. I have a thirty-four-inch waist and thirty-two-inch inseam, and the size Large Thermawrap fit me perfectly. It has a trim fit, the knees are articulated, and the legs are adequately long. Although it’s a trimmer fit, I found that I could wear the Thermawrap either under or over my hiking pants or hiking shorts. And Montbell’s 15 denier Ballistic Airlight nylon shell is lightweight, but remarkably durable and water repellent.
The Thermawrap’s full-length side zips with double sliders allow the pant to be donned without taking your boots off. It also allows temperature regulation if the pant is worn while hiking or skiing.
Now I would like to address my earlier question – are the features worth the extra weight? It depends on your intended usage. The full-length side zips with double sliders are definitely useful for winter travel on cold days. They go on without taking boots off and allow temperature adjustment by opening the zips. However, for adding insulation in camp, the side zippers are not really needed, unless you prefer to donn the Thermawrap Pant over hiking pants or shorts without taking your boots off.
To compare the Thermawrap with an alternative “no frills” insulated pant, I constructed the following table comparing the Montbell Thermawrap with the Bozeman Mountain Works Cocoon UL 60 pant, which has a Pertex Quantum shell and lining, but no extra features other than an elastic drawcord and cuffs.
|Pant||Size||Weight (oz)||Insulation||Inseam (in)||Total Length (in)||MSRP|
|Montbell Thermawrap||L||11||Exceloft 50 g/m2||33.5||44||$130|
|BMW Cocoon UL 60||M||7.4||Polarguard Delta 68 g/m2||31||45.5||$180|
|BMW Cocoon Pro 60 Side Zip||M||12||Polarguard Delta 68 g/m2||31||45.5||$230|
Some interesting comparisons are as follows:
The BMW pants run large, so a Medium Cocoon is roughly equivalent to a Large Thermawrap.
The Cocoon has thicker insulation, 68 g/m2 versus 50 for the Thermawrap.
The Cocoon weighs 3.6 ounces less.
The Cocoon has a shorter inseam, but the pant is longer because it has a longer draw (distance from the waist to the crotch).
The Thermawrap costs $50 less.
I added the BMW Cocoon Pro 60 Side Zip to the above table to provide a comparison of two similar pants. Note that the BMW Pro 60 weighs one ounce more, but it has a Pertex Quantum Endurance Mini-Ripstop shell (1.3 oz/sq2), which makes it suitable as an outer layer in cold conditions. It also costs $100 more.
The bottom line is that the Montbell Thermawrap is more versatile legwear if you want an insulated pant that can be donned without taking your boots off. It also fits very well and has pockets and has articulated knees, while the BMW Cocoon is plain and baggy. It’s also an excellent value compared to the Cocoon. Personally, I like the Thermawrap best for winter snow travel, but for summer backpacking in the mountains I will the take the Cocoon because it has the most warmth for the weight.
|2008 Thermawrap Pant|
|Unisex XS, S, M, L, XL|
|Outer shell and lining are 15d Ballistic Airlight, hollow fiber calendered nylon with DWR|
|Exceloft 50 g/m2|
|Two zippered hand pockets, zippered fly, elastic waist with drawcord and snap, full size zips with two-way pulls, all zipper, concealed zippers, elastic cuffs with snap tab, articulated knees, gusseted crotch, stuff sack|
|measured weight men’s Large 11 oz (312 g), manufacturer specification 10.3 oz (292 g) size Medium|