Good lower limb function, especially good foot function, is my first priority. Of all the components of the ski equipment system, the human component is the most important. Having the right shape of foot and leg is a good start. But having the right shape of foot and leg is not enough. You also need to have strong functional feet that are aligned straight ahead and a body that has a high degree of functional symmetry if you want to be able to ski like the best. It is possible to strengthen weak feet and correct poor body alignment. But I will save this subject for a future post.
When I examine a ski boot there are three things that I look for. The first is the general shape of the shell, the stiffness of the material it is made from and especially the integration of the overlap of the shell lower and cuff interface aka as the throat of the boot. The second thing is the shape of the boot board, the ramp angle and how well the boot board integrates with the shell base. The third thing is the material the liner is made of and the ease of removing material from it or cutting away portions.
The photo below shows what I look for in the interface of the boot shell bottom and cuff when all 4 buckles are closed to the first bale catch. I want a shell that is integrated and torsionally stiff at this interface. The interface of the shell below (black plastic on the left) conforms to this criteria.
I also want a cuff shape that is oval and stiff enough to resist deformation. These characteristics provide a degree of predictability that creates an environment my foot and leg can function in. This means getting a race shell with very stiff plastic. Although harder to insert my foot into, the predictability and stability of the defined space and volume that comes from a stiff shell trumps convenience in my books. My current boot is about a 10 year old Head World Cup size 335. It is by far the best boot shell I have skied in. Although it is still in good shape, I am considering replacing it next season with the Head Raptor.
The photo below shows what happens to the shell bottom/cuff interface of a boot shell when the buckles are closed tightly. The transition overlap of the lower shell moves towards the back of the shell. This creates an obstruction to movement of the shin during dorsiflexion of the ankle and an overlap of the cuff that is unstable.
I want the majority of the movements of my leg to happen within the consistent, defined shape of a shell cuff without the need for the shell to distort in order to accommodate movements of my leg, especially in ankle flexion. In order to maintain an integrated shell/cuff interface, I never tighten the buckles beyond the first bale catch. If the shell doesn’t adequately restrain my foot I adjust the fit in the forefoot of the tongue.
Assuming the shell is stiff enough and the shell/cuff interface is well integrated, the next thing I examine is the boot board. I want a boot board that is flat (no toe spring) and made of solid hard foam as opposed to injection molded plastic.
I check the fit of the boot board in place in the shell to make sure that shelf on either side of moulded portion integrates with the sides of the shell beyond the well that the moulded portion sits in. I check to make sure there are no discernible ridges or irregularities across the area where the balls of the feet will be.
I also calculate the ramp angle of the boot board. The boot board in my Head World Cup calculated out at 3.2 degrees. I find this interesting because it appears that Head increased boot board ramp angle to 6 degrees in their Raptor line then decreased it this season to 4 degrees.
If the shell and boot board check out, I stand in both shells without liners in my bare feet first then in one shell on one foot to find out if there is sufficient width for my metatarsals to spread under load. I also check for any interference with the inner aspect of my foot especially my inside ankle bone.
When I go to a shop to try on new boots I take my current pair with me, put on both boots and wear them in the shop for a few minutes. Then I try one of the boots I am considering purchasing on one foot and compare it to my current boot on the other foot. Next I replace the liner in the boot I am considering with the liner from the same foot of my current boot. This gives me a good idea of how the shells compare.
When I change to a new boot I keep my old pair of as a reference until I am sure that the new boot is working as well or better for me than my old boot. If I feel like there are some issues that I have a hard time identifying I can use my old boots as a reference to compare them to the new boot. I also have me the option of temporarily going back to my old boots until the issues with my new boots are sorted out. More than one racer’s career has gone downhill after they switched boots and/or ski-binding systems that had a significantly different net ramp angle, shell shape or forward lean than their previous boots.