WHAT ARE B1 BOOTS?
More rigid than B0 boots are four-season B1 mountain boots. They’re still relatively light, but are sturdier, warmer, often well above the ankle and are compatible with C1 strap-on crampons. Their leather or fabric uppers are breathable and flexible. These boots have a flat heel so don’t have the toe lips required for C2 mountaineering crampons.
Though a good all-round boot, B0 boots aren’t recommended for climbing or colder and more demanding winter mountain conditions. B1 boots are useful for general alpine terrain and less technical rock routes.
WHAT ARE B2 BOOTS?
B2 mountain boots are genuine four-season boots, with the rigid soles and uppers required for challenging winter mountain conditions, while still retaining a small amount of flexibility for general walking. Because B2 boots have thicker uppers and a heel lip compatible with C2 crampons, they’re suitable for mountaineering and mixed climbing.
Highly durable with wide-spaced lugs on the soles, along with a higher cut, B2 boots provide the support and protection needed to tackle mid-grade climbing and glacial terrain. Flexible C1 crampons can be used with B2 boots but they’re also compatible with C2 crampons with heel-clip bindings.