by Geir Mjosund 06/12/2014
Boots for any climbing over snow and ice needs to be of a type that will let you use crampons. Boots are graded according to their compatibility with different types of crampon.
Crampons and Boots
B0 graded boots are not suitable for use with crampons. The sole is not stiff enough to prevent them moving differently to the crampon with the result that the crampons will move around and may come off all together. They are also not very stiff in their upper section and may not provide enough support to your ankle or enough rigidity to allow ‘edging’ of the boot in snow when not using crampons.
B1 graded boots are suitable for use with strap-on C1 Crampons for use on moderate snow and ice conditions. They have fairly stiff soles so that the crampon does not loosen or come off as the boot during walking flexes. They are also quite fairly stiff on the upper part so that they can provide good support for the ankle and then allow edging in the snow when not using crampons. They are then again not so stiff that they are too uncomfortable to walk in when you are not in the snow.
B2 graded boots are suitable for use with C1 Crampons or C2 Crampons. They have a clip lever at the back and therefore require the boot to have a special shelf at the heel for the end of the heel lever so it can engage. The boots have a stiffer sole than B1 boots and will help to keep the crampons in place on moderate mountaineering climbs. Some B2 boots are still flexible enough to be used on an approach walk.
B3 graded boots are suitable for use with technical C3 Crampons. The boot is fully rigid and allows the crampon to be used on more technical climbs (where there is likely to be sustained use of the crampon’s front points) without the crampon loosening. B3 boots are likely to be very uncomfortable for approach walks and trekking as they are rigid and often heavily insulated.
Examples of each crampon type are shown below. Note that there are also variations on these basic ideas.
On all climbs or treks where you will use crampons, your boots will need to be rated at least B1 or B2 to use with crampons.
If you want to buy your own crampons before the trip please be sure that you take your boots to the shop and ask a expert to check the fit of the crampons with the boot. Some of the combinations of boots and crampons do not provide a good match and can lead to poorly fitting crampons and some real problems on the mountain.
BOOT GRADING FOR WARMTH
Another very important ting to consider when choosing your mountain boots is how warm they are. For anything other than technical climbing, this is likely to be the most important factor in your choice of boot. Different types of boot are constructed differently, with different materials and built up in layers. Usually on warmer boots, the layers are able to be seperated into an inner and outer boot. This helps as it allows you to warm/dry the inner’s and also to wear them inside the tent and in base camps.
It sounds obvious when it is pointed out, but if you are walking on snow, your feet lose heat through the sole of your foot into the cold ground. This is made even worse if the snow is not hard packed, as you may be ankle or even shin deep in the stuff and your whole foot and lower leg may be conducting heat to the snow. Therefore, it is also the condition of the mountain that affect which boots are needed, beside from just the altitude or location.
Then of course the warmer the boot the more volume and bulk it has to it and usually the more expensive it is too. Using a boot that is too warm can be as problematic as having one that is not warm enough. It will lead to excessive sweating which is uncomfortable and can ultimately lead to greater chance of blisters, cold feet or even frostbite when you stop working hard, the sweat conducts warmth away from your feet, or can even freeze.
Above the snowline there are four main options, in descending order of warmth:
- ‘Triple-Boots‘ for 8000m or very cold peaks (K2, Everest, Denali) such as Millet Everest, La Sportiva Olympus Mons, Scarpa Phantom 800. These are constructed with inner boot, shell and super-gaiter.
- ‘Plastics‘ like the Scarpa Vega, preferably with a high altitude rated inner boot for warmth (Elbrus). These are a double-boot with a shell and a liner boot.
- ‘Hybrids‘ like the La Sportiva Spantik or Scarpa Phantom Guide which are a double or even triple boot but the outer boot is not solid plastic so tat is can be more comfortable.
- ‘4-Season‘ boots like Scarpa Charmoz Pro these are what you would commonly use in Nordic winter conditions. They would be suitable for mountains like Toubkal or other Moroccan Atlas peaks in winter.
The images show examples of boot types mentioned above. Please note that there are often many example of boots that will do the same job.
CHOOSING AND FITTING BOOTS
Remember that on a mountain trip you will spend a lot of time in your boots and your feet will be working hard. You will greatly regret cutting any corners with selection and the fit of your boots!
If you are buying expensive boots for an expensive expedition it is strongly recommended that you visit a specialist retailer with trained staff, propper foot-measuring facilities (length & width) and a wide range of brands and models. This will allow you to try out a range of different boots before committing to one. Another important thing you should consider is to take the exact socks that you will wear on the trip with you to the shop. You need to try the boot on with the right sock as this can make a huge difference to the volume and comfort of the fit.
When fitting your boots, you often need to go up a half size or so from what you would buy in a normal shoe. This will allow for thick socks and some extra space as your feet often swelling a bit at altitude. Generally on high mountains you are walking very slowly and deliberately and will not experience the same amount of movement that you would with an approach boot. But you do need to ensure that when walking you do not experience any ‘heel-lift’ inside the boot and that there is sufficient space around your toes for you to wiggle them. Any tighter than this and it is likely that they will either rub and give you blisters or be so constricting as to restrict the blood supply and lead to cold toes and you don’t want that do you!