Winter mountain boots, from B0 to B3: what to look for in walking boots

Whatever the adventure, the right footwear is essential. Whether you are looking to move quickly over light terrain or need security on a snowy peak, you need the right tools for the job. Choosing winter mountain boots can be a daunting task. Key features include rigidity of the sole, thickness of the uppers, compatibility with crampons and overall ease of use. Mountain boots are categorised from B0 to B3  - the lower numbers are lighter and more flexible with the higher numbers more suitable for difficult terrain.

What are B0 boots?

B0 mountain boots are walking boots for three seasons, but not designed for winter use. They are flexible, lighter weight boots that are ideal for walking, backpacking and scrambling. They are not recommended for use in snow and they are incompatible with crampons.  

With a flexible sole and flat heel, B0 boots have a lower cut allowing greater freedom of movement. This makes them ideal for hiking in normal conditions. A lightweight construction allows greater comfort on long walks. They are not recommended for use in snow or climbing, Strap on crampons should not be used with these boots and are likely to damage the softer materials of the boot.

What are B1 boots?  

B1 mountain boots are three-four season boots, more rigid than B0, making them suitable for winter fell walking, while maintaining a light weight. B1 boots are compatible with C1 strap-on crampons. A good all-round boot, they are not recommended for climbing or more demanding winter mountain conditions.

An ideal hybrid that you can use all year round, B1 boots are versatile. Leather or fabric uppers allow breathability and flexibility. The semi-rigid midsole is designed to take C1 crampons. These boots have a flat heel and do not have the toe lips required for C2 mountaineering crampons. B1 boots are useful for mixed 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. B2 boots have a heel lip making them compatible with C2 crampons. 

B2 boots are suitable for mountaineering and mixed climbing. The increased thickness of the uppers in comparison to B1 adds insulation. Highly durable with wide-spaced lugs on the soles, along with a higher ankle, 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 are also compatible with C2 crampons with heel-clip bindings.

What are B3 boots?  

B3 mountain boots are rigid boots for serious mountaineering including snow and ice-climbing. A high level of stiffness in the soles and uppers give a high level of traction for the most challenging conditions. B3 boots have a heel and toe ledge making them compatible with C3 crampons. 

B3 boots give the highest level of support in both the lateral and medial axis for technical climbing in all conditions. The stiffness of these boots makes them less appropriate for general hiking in normal conditions. C3 crampons can be fitted to B3 boots although lighter C2 crampons can also be used, depending on the terrain.