Smartwool Classic Mountaineer Maximum Cushion Review

The Mountaineer Maximum Cushion is everything that it states — a high Merino wool blend sock with lots of pile and maximum cushioning, built for the most extreme cold weather environments. It's less versatile than some of our other options, but it's top of its class for wintry or cold weather applications.

Performance Comparison

Comfort

This sock had one of the highest Merino wool blends that we tested — 74% Merino wool, 17% recycled nylon, 8% nylon, and 1% elastane. The Merino wool offers plush soft comfort, and the cushioning is among the highest in its class. We like that Smartwool incorporated recycled materials — peace of mind can be just as important as bodily comfort.

We wanted to test the “maximum cushion” of these socks, so we hiked with our two plushest cold weather socks side by side. Testing confirmed that the cushioning and comfort of the Classic Mountaineer is superior to most other cold weather socks on the market. It scored lower in this metric only because it's less form-fitting and less versatile. The sock is bulky and doesn't have compression paneling to hold it in place. This makes for a less specific fit but also allows you to wear liners underneath for added comfort on long, cold treks.

Wicking and Breathability

Even though the Mountaineer is a heavyweight sock, it measured in the middle of the pack for wicking and breathability. This is due to ventilation panels that run on either side of the instep and looped construction that helps move moisture away from the skin. Although it's 74% Merino wool, the 25% nylon in the blend lends to the wicking action.

We tested these socks during expeditions, long hot work days, and cold, damp nights along the coast. We found that on the hottest of days, our feet stayed surprisingly dry — even in boots. On cold nights when we were using the socks to keep our toes toasty, our feet stayed warm throughout the night, and if we were sweating, the socks did a superb job of wicking away the moisture. We also verified that the Mountaineer could hold up even after days of use. They'll take a lickin' and keep on keepin' your feet toasty and dry over the miles and days.

Warmth

These socks are built to protect you from the cold. Of all that we tested, they are the warmest and most plush. The high wool content ensures that feet will stay warm even in cold and damp conditions, while the superior wicking ability of the looped construction ensures that your feet will continue to stay warm and dry throughout the day.

While these socks are superb for mountaineering, skiing, and winter backpacking, we also found that they are swell for sleeping. They quickly became our go-to for a warm sleeping sock to keep our toes toasty when the cold night was nipping at our feet. The pile holds up well during use, so even if you only bring one pair of socks on your trek, these will keep working to keep your feet warm day and night despite the wear.

Durability

Due to the thickness, these socks are more durable than most. Despite our best effort, we haven't worn any holes, and the cushioning remains, adventure after adventure. Merino wool is generally less durable than synthetic fabrics, but a good blend in these socks ensures that you'll get a lot of use before they become cleaning rags.

At first, we questioned the durability of the looser stitch design of the Mountaineer. Although a looser stitch may increase the breathability of a thick sock, it doesn't always enhance durability. The threads on these socks tend to fray with use, but we didn't find that this affected the durability. The socks retained their performance despite this perceived drawback.

Drying Speed

Wool is slower to dry than synthetics, and even though these socks are 25% nylon, the high wool content makes them slower to dry than lightweight and mid-weight socks. During our testing, they took the longest to dry on the line — 200 minutes in 80°F weather.

We recommend you take an extra pair if you're embarking on a long cold trek. Each day you can dry your worn pair by the fire while you don your warm, dry pair to lounge around camp.

Should You Buy the Smartwool Classic Mountaineer?

If you're looking for a warm sock for cold wintry activities, look no further. The Classic Mountaineer Maximum Cushion offers unbeatable warmth, superior wicking ability, and comfy cushioning that will endure the miles. This sock is also a top contender for the most comfortable sleeping sock. It's a great one to throw in your pack when your days are warm, but the mercury drops at night. Your feet will stay snug as a bug in a rug while you recount the day's adventures by fire or lantern light. And you can rest assured that the night's cold won't nip at your toes. We recommend against using these socks anywhere you'll encounter stickers, burrs, bramble patches, or anything else that will cling or pull at the fibers. Their plushness becomes a weakness in these situations.

What Other Hiking Socks Should You Consider?