What is the difference between keen ice and heavy ice

The curling stone's concave bottom, which limits how much it comes into contact with the ice, and the pebbles reduce friction. Essentially, the pebbles melt a bit when the heavy stone runs across them, creating a micro-layer of water upon which the stone can glide.

Sweepers—those furious ice brushers who've become fodder for Olympic memes and GIFS —use a broom to brush the pebbles, thereby changing how the stone spins.

Specific techniques melt the pebbles, reducing friction and helping the stone travel even farther and straighter. Naturally, the game changes as the pebbles erode, and sweepers have to constantly compensate. So while strategy is left to the athletes, pebbling falls on the shoulders of ice technicians like Shawn Olesen, a North Dakotan who spends most waking moments thinking of the science, and art, of creating the perfect curling ice.

While he was not part of the crew to prep the curling ice in Sochi, he does travel the country building surfaces for the United States Curling Association USCA , the organization responsible for the championship events that send American athletes to the Olympics.

These conditions helped carry the stone to the other side of the ice. The process actually starts well ahead of competition. Host arenas Olesen works with send water samples to a company called Jet Ice so that PH levels and purity can be measured.

The goal is to have the most neutral water source possible, with close to no dissolved solids, Olesen says. Clean water is easier to manipulate into perfect pebbles on the ice. From Jet Ice, Olesen recieves tools—from carbon filters to water softeners and anti-ion tanks—custom built for each arena so the water can be purified before it hits the ice. Olesen and a team of up to 12 people will arrive at a competition site four or five days ahead of the event.

The team uses a laser level to make sure the existing ice is as flat as possible—within half an inch—and shaves off inconsistencies. They paint over hockey lines, draw throwing circles, logos and other curling-specific markings and put foam around the edges of the long, narrow game sheets. From there, they flood the playing surfaces with water; carpet is laid around the foam's edges. From a water tank on their backs, workers spray purified water through a copper wand, which drops pebbles across every inch of the plus-foot curling sheet, much like a sprinkler moving back and forth across a lawn.

Each pebbling can is different, with varying numbers of holes, producing pebbles in a range of sizes. Some technicians measure the number of droplets per centimeter, Olesen says.

Each ice maker has his own preference for pebble size and pebbling technique," he adds. Crews lay down two coats of pebbles on each game sheet. Get this if: You are the type of winter warrior who is always in and out of the house—shoveling, taking out the trash, visiting the neighbors—and therefore always pulling boots on and off.

Winter rubber can stay softer at lower temperatures, and soft rubber is grippy rubber. However, very few soles provided a noticeable difference in traction at all, with two exceptions. With no knowledge of what was under their feet testers were not informed of what their boots were made of , our team reported better traction walking on smooth ice in these boots and in the Danner Arctic. There are some fit differences between this and more traditional boots, such as the Kamik and Sorel boots.

That makes this boot much easier to slip on and off for quick entries and exits than the lace-up Danner. Typically, this foot movement causes some instability on ice and snow. In this case, the rubber returns much of the traction lost by the fit, and in a noticeable way. Flaws but not dealbreakers: The major flaw with this boot is the wide top opening.

If you step in snow deeper than the boot, you get a foot full of snow so much for all that waterproofing. There is also a knee-high version available for men and women , if you prefer. The faux fur on this slip-on boot sets it apart—the warmth, the cozy sensation, and even the additional stability it provides make it worth recommending. Get this if: You prefer a cozier slip-on that will still keep you stable and dry while you are shoveling and running errands.

What you gain in convenience with rubber, slip-on snow boots you sometimes lose in ankle stability which really impacts traction. In the case of the Bogs Arcata , the faux fur lining helps address that issue. But in the case of winter boots, faux fur is a big advantage! The original native mukluks used fur for warmth, and in this case, the faux fur lining goes all the way over the toes.

It makes an all-rubber boot, which can feel loose around the feet, fit more snugly and therefore behave more stably on loose snow, packed snow, and chunky ice. Flaws but not dealbreakers: As with every slip-on boot, the top is open, and snow can get in. Snow can also get in through the cut-out handles. And we think they still do the job better than any other similar option. Flaws but not dealbreakers: There is no traction advantage.

We began our research by seeing what other review sites had to say. These are the features we focused on:. Waterproofing: A waterproof sole is a good, obvious place to start. But the shaft height of the boot, as well as how snugly it fits around the leg, also makes a difference. We chose boots that had tall shafts, about 8 to 10 inches. They keep snow out! We also looked for boots with snow collars, which line the opening of the boot and keep snow from falling in or clinging to your leg.

Warmth: We chose to test boots that use gram insulation in their design. That means one square meter of insulating material weighs grams. Warmer boots, meant for standing still in the cold, often have heavier insulation— grams, grams, or more. We also sought out boots with reflective layers, which send body heat back to the wearer. Columbia aggressively markets its reflection tech as Omni Heat, but a lot of brands do this, including Baffin, Kamik, and others.

This design increases warmth without adding bulk. As for temperature ratings, we were initially skeptical of temperature ratings provided by manufacturers. But when we had testers tell us how warm a boot felt, subjectively, their impressions were a relative match—boots with warmer ratings felt warmer, and those with colder ratings felt colder.

Traction: A great winter boot sole is hard to design, because it has to navigate so many surfaces. We sent our testers out with clipboards and charts and had them rate traction on every one of those different surfaces.

Though sticky, winter-specific rubber gets all the attention, we discovered there are four ways a boot can gain and improve traction on snow and ice:. That depends on what you need. Laces give you a better fit and a lot of traction, and that makes a good ice boot and a good walking shoe. Slip-ons are functional for going in and out of the house 10 times a day. So we chose a few of each, and if a shoe somehow integrated both functions, even better. It seemed more important to find what worked, and then discuss why.

We were having some stock issues with the Danner Arctic Side Zip for men and women , our former pick for walking on ice. There was a significant amount of heel lift for all our testers that made them hard to wear.

The L. Bean Snow Boots for men and women are rain boots masquerading as snow boots. Columbia Heavenly Slip II and Shorty Omni-Heat have the same snow-friendly foot shape as our pick, the Columbia Heavenly Omni-Heat , but without the laces or tall shaft height, there is less ability to keep snow out of your boot and off your pants. And they had the worst traction of every boot we tested imagine plastic on ice. The boot has been discontinued for winter ; it appears to have been replaced by the Chilkat Nylon II boot , which has an even shorter shaft, and the Tsumoru Boot , which also appears to be quite short.

And though we liked that about this boot, the fit was off. The ankle was very soft, and the boot itself is huge. The Sorel Pac 2 boots for men and women have rain-boot treads and are slippery in snow. If you want a pair of boots in this style, and want them to last more than a season, we recommend going with the UGG shorty. The Uggs come already coated and ready to wear. When we went searching for new boots to test this year, a lot of places were out of inventory.

But we have plans to get our hands on some new models from The North Face and Kamik as soon as things are back in stock. Eve O'Neill is a senior staff writer reporting on travel and outdoors at Wirecutter. She has always been drawn to ideas about how to relate to, and play in, the wilderness.

Who this is for. What does this guide not cover? Winter work boots, or extreme-cold boots, which are heavily insulated to keep feet warm for long periods of time and sometimes have features like reinforced toe caps or electrical hazard protection. Winter hiking boots. A few made it into the test pool since hiking boots are built for walking, albeit on trails, and that has some crossover appeal. But winter hiking boots have more sophisticated lacing which can help with traction than boots made for in-town use.

And the shaft height how far the boot comes up your leg is shorter, usually 5 to 7 inches, which makes it easier to flex your ankle, and in turn makes walking and driving easier. There are millions of these—pick whatever you like! A mukluk is a soft-sided, often knee-high animal-skin boot originally worn by the aboriginal tribes of the Arctic, especially when hunting and dog-sledding.

They have one of the highest warmth-to-weight ratios of any winter shoe and are ideal for walking through deep snow without getting your feet stuck. Why you should trust me.