Alpine touring (AT) boots are different from alpine ski boots. AT boots are designed for both downhill skiing and ascension using climbing skins, while alpine boots are primarily downhill-oriented. AT boots have a supportive ski mode for skiing downhill, plus a flexible unlocked or "walk" mode that lets your ankle and lower leg flex forward and back for skinning and bootpacking uphill. AT boots usually have a curved (rockered) and lugged rubber sole like a hiking boot that gives improved grip on slippery surfaces and lets you walk more naturally. They also focus on lightness and are increasingly made with lightweight materials like Pebax®, Grilamid, and carbon fiber to save weight without sacrificing performance.
The AT and backcountry market is expanding at a tremendous pace, with dozens of alpine touring boot designs available in a wide range of uphill and downhill capabilities. Do some research before you buy and figure out what your needs are.
Things to consider:
- What type of skiing do you plan to do in this boot? Big-mountain riding on wide skis or week-long hut trips in the Alps?
- Do you plan to use this boot in the ski area, or strictly for touring?
- What shape of foot do you have, and which brands/models fit your foot best?
- What style of AT bindings will you be using with this boot?
- What's your ability level, and how supportive of a boot do you need to ski all the conditions you might encounter in the backcountry?
Uphill Weight vs. Downhill Performance
Some AT boots come close to or surpass alpine boots in stiffness and downhill performance while adding a walking hinge and lugged sole. These boots are suitable for strong and experienced skiers who plan to ski all types of terrain and want to use the same setup both in and out of bounds. Sometimes referred to as "crossover" boots, these AT boots will normally be on the heavier end of the spectrum and have flex index numbers (the rating system to determine stiffness) in the same range as high-end alpine boots, i.e. 110-130. While these boots excel on the descent, weight and sometimes cuff mobility may make them less suitable for skinning – you’ll have to decide for yourself on the weight vs. performance question. Factors that influence this decision are skiing style, fitness, and terrain choice.
Lightweight AT boots, on the other hand, are a dream to skin uphill with but may sacrifice some downhill performance. How much performance you’re willing to give up is highly personal and depends on ability level, skiing style, and fitness.
If you plan to use an AT boot for all of your skiing, both lift-served and touring, it helps to make an honest assessment of how much of each you’ll be doing and choose your boot with this in mind.
The AT market is dominated by a small number of manufacturers with decades of experience, but many alpine boot makers are now making touring-oriented crossover AT/alpine boots that fill the needs of the aggressive AT boot customer. Companies often have a fit "profile" that is consistent throughout their line, but there are variations between models, so it's important to check out the specifications of each one and try the boots on if possible.
Comfort with AT boots is critical - you can't go down to the lodge and take your boots off when you're miles away from the trailhead. Many people skin with their top buckles loosened (causing more fore/aft movement of the foot), so experienced backcountry skiers may fit their AT boots a little more generously than alpine boots in length.
Last and width for AT boots is typically more generous than performance alpine boots. Forefoot widths in the 100-103 mm range are most common.
Many AT boots include a thermo-formable liner, which makes for a warmer and more accurate fit. Deal with fit issues before you head out on a trip - aching feet and blisters can be more than just an inconvenience in the backcountry.
Remember that not every AT boot will work with every alpine touring binding.
•All tech bindings (e.g. Dynafit) require a boot with molded-in toe fittings and a slotted plate at the heel. If you wish to use these bindings, you will need to have a boot with these fittings.
Dynafit boot with molded-in fittings to use with tech bindings
•MOST AT boots and alpine boots will work with MOST frame AT bindings (like Marker and other brands), but be sure to check the manufacturer’s recommendations. Boots with minimalist soles like the Dynafit TLT5 and TLT6, Atomic Backland series, La Sportiva Stratos/Syborg and Scarpa Alien series boots are compatible only with tech bindings.
•Manufacturers of the Salomon Guardian and Atomic Tracker bindings recommend using pre-2014 / 2015 models of those bindings only with WTR (Walk to Ride) flat soled (non-rockered) AT boots or alpine boots. 2014 / 2015 models with sliding AFD's are compatible with ISO 9523 (rockered) Touring soles.
•AT boots with rockered ISO 9523 Touring soles are not compatible with ISO 5355 Alpine bindings. Even if they fit, release may not be consistent. The exceptions are the Marker Lord SP and Salomon/Atomic Warden bindings, which are compatible with both types of soles.
•Some AT boots designed for performance downhill skiing offer interchangeable alpine and tech soles, which enable you to switch between alpine bindings and tech AT bindings with the same boots. Some boots come with the interchangeable sole included, while other brands charge extra for the second sole. The K2 Pinnacle 130 and 110 boots offer a non-rockered sole with tech fittings, designed to be used in any type of binding.
The question of how much boot you'll need to confidently ski all terrain and conditions can be more complicated than you think and depends on the individual and the day. Even the experts are constantly adjusting their idea of what boot works best for them, so don't feel bad if you aren’t able to figure it out right away. If in doubt, choosing a slightly heavier, more supportive option is probably safer. While this may seem inconvenient on the way up, the added security of a sturdier boot can make all the difference on the way down.
Common AT boot questions:
Can I use AT boots with my alpine bindings? It depends. Most crossover AT/alpine boots are designed to be compatible with alpine bindings. Although some alpine bindings will adjust to accommodate the higher AT boot toes and it may physically fit in, manufacturers warn against using true AT boots in alpine DIN bindings because the added grip of rubber soles can prevent the boot from properly releasing during a fall. Some AT boots come with or have available aftermarket alpine soles that can be installed by the user and are designed for use with alpine bindings. The Marker Lord SP binding, and the Salomon / Atomic Warden binding allow use of either ISO Alpine or Touring soles. Ask a certified ski tech if you are uncertain about a specific boot / binding compatibility issue.
Can I use an AT boot for all my skiing, lift-served as well as touring? Many people do this successfully, including many ski professionals. A one-boot quiver may involve some compromises, though, in binding choice and downhill capabilities.
Will an AT boot be as durable as my alpine boots? It depends. Beefy AT boots will last for years even when worn on a daily basis. Light boots with thin shell walls and streamlined hardware may not. Rubber soles may wear quickly if you scramble over rock or walk on hard surfaces frequently.
How much performance will I give up if I switch to AT boots from alpine boots? Maybe not much at all, but it depends on which alpine boot you’re coming from. The latest crop of high-performance crossover AT/Alpine boots are very close to high-end alpine boots in stiffness and response and still have decent tour modes.
Can I retrofit tech fittings into my current AT or alpine boots? Not recommended. It's been done, but it's time-consuming and easy to mess up, plus you have to locate a pair of old tech boots to scavenge the parts out of.
Can't I just skin in my alpine boots? Yes, but the question is for how long? Most people find skinning for any length of time in alpine boots that don’t have a walk mode quite uncomfortable.
**You should carry an avalanche beacon, shovel and probe when travelling in avalanche terrain and know how to use them. Backcountry travel requires an acceptance of the risks involved (avalanches are not the only danger) and implies a willingness to take responsibility for educating oneself about these dangers and ways to mitigate them. We recommend that backcountry travelers take an AIARE Level One class or the equivalent, and practice the skills they learn there regularly with their partners.