Reassessing My Ski Boot Setup

What ankle mobility, ramp angle, and forward lean taught me about separating variables in ski-boot setup.

Early in my pathway to high-performance skiing, I struggled with two recurring pieces of feedback. The first was a tendency to “settle” at the end of the turn, flexing more at the knee than at the ankle or hip. I had the strength to ski through this slightly aft position, but at times would leave the snow during transition in a dolphining maneuver.

The second was that I didn’t move through the ankle enough.

The two seemed connected, but maybe not in the way I initially thought.

Three Pieces of Boot-to-Ski Geometry

Before getting into what I changed, it helps to separate three pieces of boot-to-ski geometry that are often discussed together.

Boot-Board Ramp

Under the liner is the boot board, or zeppa, which typically has 2° to 5° of ramp—the heel sitting higher than the toes.

Cuff Forward Lean

Next is the forward lean of the cuff. Modern ski boots typically have 13° to 18° of forward lean.

For this discussion, I use forward lean to describe the relationship between the boot cuff and lower leg, while ramp describes the heel-to-forefoot angle inside the boot.

Binding Delta

Lastly is binding delta, which is also created by a difference in heel and toe height. For a given binding, shorter boot-sole lengths therefore produce greater delta angles.

RAMP

Heel-to-forefoot angle inside the boot

FORWARD LEAN

Relationship between the cuff and lower leg

BINDING DELTA

Heel-to-toe height difference created by the binding

The Idea Started in the Gym

I like to discover solutions for myself, frequently making changes without telling anyone and then using feedback from trusted peers to see whether they work.

The idea for addressing my skiing feedback started in the strength gym.

I was coaching squat technique and demonstrating ways to achieve full depth when ankle mobility is limited. One option is placing small weight plates under the heels to create a ramp angle. Elevating the heel reduces the ankle dorsiflexion required to reach a given squat depth, which is one reason weightlifting shoes have thicker heels.

Someone pointed out that I could demonstrate proper depth barefoot because I had good mobility through my ankles, knees, and hips.

That led to a question:

If heel elevation is commonly used to accommodate limited ankle mobility in a squat, why was I elevating my heel inside a ski boot when I had plenty of ankle mobility?

From Observation to Hypothesis

I started researching dorsiflexion. Using the weight-bearing knee-to-wall test and its established normative values, I confirmed that I have a high range of ankle dorsiflexion.

There is no established formula connecting ankle dorsiflexion to ski-boot setup, so what followed was a hypothesis.

I wondered whether the combination of my ankle mobility, boot-board ramp, and cuff geometry was putting me farther forward than I wanted to be. If so, dropping my hips back and “settling” could have been a way of compensating for that position.

Changing One Variable at a Time

My ski boot has an aggressive amount of forward lean and a moderate amount of ramp.

I began by removing most of the ramp from the boot board, lowering my heel relative to my forefoot without changing the cuff.

On snow, however, I lost some feel for the front of the ski.

I added a spoiler to progressively increase cuff forward lean until I got that feel back.

The important distinction was that I was now creating the lower-leg position through my available ankle range of motion rather than by elevating my heel.

What I ultimately wanted wasn’t necessarily less forward lean.

I wanted less ramp.

What Happened on Snow

After these changes, there was less mention of settling or insufficient ankle flex, and I found it easier to move through a more flexed transition.

Importantly, the people providing that feedback didn’t know what I had changed.

That doesn’t prove the equipment changes caused the improvement, but the pattern was consistent enough to convince me that ramp and forward lean were worth treating as separate variables.

One Variable Left

There is one more variable I haven’t addressed: binding delta.

Interestingly, one of the skis I used most last year—and received the most favorable feedback on—has zero binding delta.

I’ll have more on that in another article.

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