BorealG1 Lite Mountaineering Boot

A tough, light, and capable alpine boot.

Boreal's lightest double boot, the G1 Lite Mountaineering Boot was designed and built for the fast-moving alpinist and 6000-meter summit bids. The tough outer boot is composed of a combination of Teramida textile, Lorica synthetic leather, and ceramic-reinforced stretch Cordura nylon. Six millimeters of EVA foam insulation behind that offers warmth in addition to the triple-layer Thinsulate insulation in the inner boot. The inner boot is also fitted with a heat-reflective aluminum layer to redirect heat back to the foot for reliable warmth in cold and high alpine conditions.

For protection against moisture, Boreal built the outer boot around a waterproof and breathable Cordura nylon lining and put its Dry-Line waterproof and breathable membrane with fully sealed seams in the inner bootie. A stiff and light carbon composite midsole made with layers of PU and EVA weaved between offers shock absorption when toeing in on sections of bulletproof blue ice. TPU toe and heel welts make the boot compatible with automatic crampons for quick attachment during still-dark alpine starts.

The entire boot is built on a deeply lugged Vibram Teton sole for a sure-footed feel when climbing without crampons on. Making the boot more comfortable while hiking and climbing is the addition of Boreal's Bi-Flex system, which consists of soft compressible panels that act like hinges for a progressive forward flex and better forward and lateral flex, making the boot a bit more comfortable to hike and climb in that stiff and unforgiving mountaineering boots.

  • Boreal Dry-Line waterproof and breathable membrane
  • Cordura-Sympatex waterproof and breathable lining (outer boot)
  • 6mm EVA foam insulation (outer boot)
  • Triple-layer Thinsulate insulation
  • Teramida with Lorica ceramic reinforced stretch Cordura upper (outer boot)
  • PU inner bootie with heat-reflective aluminum film
  • Tanka, lace, and hook-and-loop closure
  • Ultralight carbon composite midsole
  • EVA and PU shock-absorbing layers
  • Bi-Flex system
  • Vibram Teton rubber sole
  • Automatic and semi-automatic crampon compatible
  • Reviews
  • Q & A

Light and Right

  • Familiarity: I've put it through the wringer
  • Fit: True to size

I can't say enough good things about these boots. For a super warm double boot, they are incredibly flexible and comfortable. The flexible upper provides a fit that is way more comfortable than the La Sportiva Baruntse and can be laced snug for climbs that require some precision footwork without worrying about shin bang. The comfort extends to approaches over rock and as far as warmth, it's a non-issue. The only thing to be aware if is that these things have a huge footprint so I needed the extender bars in order for BD crampons to fit my size 11.5s. All in all a fantastic boot that I'm looking forward to wearing until it wears out.

Light and Right

How is the fit on these? true to size? Would you say they run more wide or narrow? I typically wear Scarpa boots; my street size is 9.5 but I usually wear 10s in mountaineering boots. I'm wondering if these would fit for me. Thanks in advance.