The Kamik Viper is an all-synthetic boot with 200 gram Thinsulate insulation and weighs just 20 oz/boot (manufacturer specification, size men’s 9).
For lightweight insulated footwear, we prefer boots with all synthetic uppers and a minimum of 200 gram insulation. The Kamik Viper (introduced fall 2007) has a durable ballistic nylon upper and 200 gram Thinsulate insulation and weighs just 20 ounces per boot (manufacturer’s specification for men’s size 9). The Viper had been one of our favorite insulated boots based on its specifications, but our field testing gave us some second thoughts, described below.
Views and details of the Kamik Viper: The boot is 8.5 inches tall, the rubber outsole has a unique traction tread, and the upper (inset) is made of a durable ballistic nylon.
Although the Viper is specified to have a D width, we found it a bit narrow compared to other insulated boots. To get a good fit for Will’s wide feet, he went up a half size and used a thin footbed and thin wool socks. For Janet’s “normal” feet, she sized up a half size to make room for a thicker footbed and heavy wool socks. Overall, the Viper is a good choice for hikers with narrower feet, and we recommend sizing up at least a half size to make room for heavier socks.
The Viper is insulated with 200 gram Thinsulate, which we consider adequate for active winter pursuits, but minimal (or inadequate) for less active pursuits like winter camping. This boot is rated to -25° F, which we believe is incorrect or wildly optimistic. The reality was that our feet were warm in the Viper on warmer winter days and more vigorous activities, like snowshoeing uphill, but both of us experienced cold toes on colder days (below about 20° F), especially when we stopped to take a break.
Since the upper on the Viper is just fabric (ballistic nylon), we found the Viper to be best suited to snow travel and snow play, like snowshoeing and snow hiking. We tried them for cold weather hiking in mostly dry conditions, and found them less supportive than we would like. There is very little ankle support other than lacing the boots tighter, and no TPU plate in the midsole to add stability and support. They handle flatter terrain just fine, but are less supportive in off-camber situations
The Viper does not have a midsole TPU plate, so it is not very supportive for hiking in rougher terrain or backpacking. We found the best use to be snow travel and snow play, like snowshoeing.
Kamik uses a technology called OutDry in the Viper to make them waterproof and breathable. Briefly, the technology permanently bonds a waterproof-breathable membrane to the stitched boot upper before the boot is assembled. Details of the process are available at OutDry’s website. In our testing, we found the Viper to be waterproof in dry snow conditions (below freezing). When we weighed our boots after each trip, we found less than an ounce of moisture per boot, which most likely was from our feet sweating. However, in our wet snow test, where we hiked in very wet snow for an hour, the Viper gained almost three ounces of water per boot. And in our traditional water immersion test (boots placed in a pan of water covering the toebox for one hour), each boot gained five ounces of moisture.
Upon close inspection after each trip, we found that the interior moisture was concentrated in the toe area where the boot flexes. Apparently the stretch and compression in this region pumps water through the membrane. We also noted that the outer shell fabric soaks up water in the toe and ankle areas. Although Kamik claims that the Viper’s OutDry membrane and ballistic nylon shell keep the boot waterproof, our testing revealed that to be the case only in dry snow conditions (below freezing), but not in wet snow or water.
Overall, the Kamik Viper is a decent choice for a lightweight insulated boot. They fit best on narrow and medium width feet; hikers with wide feet should consider other brands and models. Their 200 gram insulation is adequate for active cool weather pursuits, but not enough for really cold weather or lower activity levels. The OutDry membrane and nylon upper effectively exclude water from the interior of the boot in dry snow conditions, but we were disappointed that the boots are not waterproof, as claimed, in wet snow conditions or in water.
Specifications and Features
|Uppers are ballistic nylon, midsole is compression molded EVA, outsole is rubber|
|200 gram Thinsulate|
|OutDry waterproof-breathable membrane, moisture wicking lining, padded collar, gusseted tongue, Kamik comfort footbed, rubber toe guard and outsole|
|Measured weight: (Women’s 7) 19.4 oz/boot (550 g), (Men’s 12) 24.1 oz/boot (683 g), |
Manufacturer specification: (Men’s 9) 20 oz/boot (567 g)