Every product is carefully selected by our editors. If you buy from a link, we may earn a commission.

How Smartwool Is Making The Ultimate Sock for Mountaineers

Smartwool’s new sock uses a patent-pending technology to make the most breathable, durable sock on the market for hiking and mountaineering.

“I‘m really crazy about foot care,” Conrad Anker, the mountaineer, says. “If your feet aren’t working, nothing is working.” He takes off his shoe and removes a sock and hands it to me in the backseat of the car as we drive along a stretch of I-75 between Chattanooga and Cleveland, Tennessee, en route to the mill that knitted this sock. “Pardon me,” he says. “This shouldn’t be too smelly.”

These socks are a prototype in its 9th or 10th iteration, designed and in testing for a fall 2016 release as the PhD Outdoor Mountaineer Sock by Smartwool, milled at the Renfo production facility in Cleveland, our destination. Though a custom sock is a largely unnecessary indulgence for most people, when you’re one of the most accomplished mountaineers in the world your feet benefit from a higher level of tailoring to help negotiate the difficult terrain and harsh conditions they encounter.

Anker has been working closely with Smartwool Director of Sock Development John Ramsey, whose family business has been in sock design for four generations. For this sock, Anker requested varying degrees of cushion — thick in the heel and toe, for example, and thin above the ankle — plus compression to keep the sock in place and to aid in muscle recovery. On top of that, the sock needed to be durable and breathable on his long expeditions in the Himalayas. Merino wool is breathable — and it adds a bit of “scratchiness” that Anker says is good for improving circulation when you’re in cold alpine climates — and is naturally a durable fiber. But to use a merino sock in a mountaineering boot, day after day, without having it fall apart, there’s some novel engineering required.


Wool’s “scratchiness” is good for improving circulation when you’re in cold alpine climates, according to mountaineer Conrad Anker.

Smartwool’s latest-generation technology, Indestructawool, allowed Ramsey’s team to execute Anker’s specific sock needs. Ramsey describes it as a “durability-based solution system” that balances comfort, fit and durability by incorporating three separate pieces into the sock: the skin (merino wool), the skeleton (elastic, made of lycra and nylon) and armor (nylon). “In short,” Ramsey says, “everything we’ve seen that exists out there is a two-piece system. We’ve created a three-piece system, which is all about putting the right yarns in the right places for the right reasons.” The merino skin provides comfort and breathability; the skeleton provides a foundation and stretch-to-fit properties; the armor is used as plating on the outside of the sock to protect against abrasion to the merino on the inside. Indestructawool, according to Smartwool, resulted in a 33 percent increase in durability over their previous technology, a two-piece system called Reliawool.

Hundreds of computerized knitting machines line the floor where the socks are made, each with up to 200 needles pulling yarn from up to 20 different cones hanging above them. Every few minutes they produce a sock. The machines are made by an Italian company called Lonati, which is the industry standard for companies making high-end socks of all kinds, and especially merino wool socks that retail for anywhere from $15 to $30 a pair. The machines have limitations, though, such that you can’t just turn them on and have something like Indestructawool roll out. Smartwool relies on their Development Manager, Greg Neyman, who works together with the mill employees to physically alter the Lonati machines so that they can knit socks like the PhD Outdoor Mountaineer.


“We have to manipulate the machines to run what we’re being asked to run,” Robbie Townsend, the plant manager, says. “That’s what we’re good at. My guys can custom cut jacks and all kinds of parts to custom make whatever Smartwool wants.”

Ramsey compares the mill workers and Neyman to Nascar drivers who know how to make the most of a very high-performance machine. “I can’t get into a Nascar car and win a race,” he says. “And I can’t jump on a Lonati machine and make it do what Greg can. We have a very talented technical team. They can get into the car and win the race, and we pride ourselves on having that skill set in house.”

Smartwool’s Indestructawool technology that provides the foundation for Anker’s sock is available now in their PhD Outdoor Medium Crew Socks and a handful of other styles at REI. The PhD Outdoor Mountaineer Sock will be available in Fall 2016 for $35. In the meantime, Anker will be putting the final version in the field at his local Hyalite Canyon in Montana, and perhaps soon on another big wall Himalayan adventure like Meru.

Learn More: Here

Conrad Anker’s Foot Care Tips

Stop for Lunch: “If you stop for lunch and you’re going to sit for an hour — and enjoy lunch, don’t ‘hut hut’ the whole time — take your boots and socks off, turn your socks inside out, dry them out, and get your feet in the sun.”

Soap and Water: “At base camp, every day, wash your feet with soap and water.”

Hand Sanitizer: “After washing my feet, I take hand sanitizing and give them a quick rub with that.”

Apply Grease: “Then I use a lot of hand grease and foot lotion because if you have dry flaky skin you’re more susceptible to frost bite. It’s a little counterintuitive: 20 years ago you didn’t want to have sweaty feet so you’d shake Dr. Scholl’s foot powder on to desiccate, but now you add that layer of fat just like the channel swimmers back in the day. My feet on summit day are gonna feel kinda squishy.”

Advertisement - Continue Reading Below
More From Camping