[Editor’s Note: We posted this article by Charlie Bradley last fall, and if you missed it back then, you don’t want to miss it now.]
We’re at the start of the 2012/13 season, so it’s a good time to be thinking about boots again. I ended my Boot Fitting 101 article promising to talk about boot sole lengths and how to make the boot your own, so we’ll pick up there.
When I started boot fitting in the mid eighties, the lengths of the boot soles were much shorter than they are today. For example, 15 to 20 years ago, a size 27/27.5 shell measured 310-312mm. That same size today will measure 316-320mm! Mondo sizing—the distance from the back of your heel to the end of your longest toe, measured in centimeters—was almost unheard of. So why the change?
In Boot Fitting 101, I talked about how a ski boot should fit suspiciously snug. The biggest problem with the boot fitting problem is that the boot often feels too short to the customer out of the box. (As true as this is today, imagine what it was like 25 years ago when boots were ~7mm shorter.) Boot manufacturers started making their boots longer to try to mitigate the problem of constantly hearing, “this boot is too short.”
So how does a new (or even experienced) boot buyer and boot fitter actually know what size they are getting? One simple rule of thumb is to subtract 40mm from the boot sole length. Why 40mm? This is the combined measurement of the toe and heel lugs of the boot. So, for example, if you’ve got a 315mm boot sole length, you subtract 40 to get 275. Divide by 10, and you’ve got your Mondo length: 27.5.
However, while this calculation will help you arrive at your Mondo length, it’s most helpful just to know your boot sole length. (I can’t stress this enough.) If you know your boot sole length (BSL) number—assuming it’s coming from a correctly sized boot (again, see the Boot Fitting 101 article)—you’ll know what size boot you’ll need when you begin to try on boots from various manufacturers.
Boot sole length is always stamped onto the heel lug. Memorize this number.
Most boots are stamped and are accurate to within 1 or 2mm. Do the math and when you find what you think is the correct size, shell size yourself. Or just go to a qualified fitter and he or she can do all the dirty work for you.
Making The Boot Your Own
Once you have found the right size and the right shape, now what? Are you ready to ski? Most people would think so, especially those who are relatively new to the sport. But there are still some things you can do to enhance fit and improve performance. The first thing is to get a custom foot bed.
A custom foot bed finishes the fit of your boot. It creates a foundation that mirrors the shape of the bottom of your foot that not only stabilizes the foot but transfers maximum force to the edge of the ski.
Now, I’m not talking about one of those “off the shelf,” “trim to fit,” pre-formed foot beds that so many shops are fond of pushing because it is an easy $40 sale. I’m talking about a truly customizable insole, one that is actually molded to your foot!
There are a number of these types of foot beds on the market, and what you buy will depends on what your shop sells. The most important thing with a custom foot bed is not that you get the right brand, but that you get the right type of foot bed. An experienced boot fitter should be able to recommend an insole for you based on a couple of different criteria.
• Windlass action
• Forefoot mobility
Dorsiflexion is the ability to bend or close the ankle joint. In general, the more flexible you are in the ankle joint, the more supportive a foot bed you’ll need. Conversely, the more rigid you are in the ankle joint, the more flexible (or shock absorbing) the footbed should be. Here are examples of limited (or rigid) dorsiflexion, and excessive (or flexible) dorsiflexion.