⛷️

SKIING WITH A SMILE · FOUR-PART SERIES

The Secret of a Reliable Kick

PART 1 OF 4

 

The Secret of a Reliable Kick – Part 1: Choosing the Right Ski Length and Stiffness

There are many things that determine whether a classic cross-country ski will provide a reliable kick.

Unfortunately, not all of them can be fixed with another layer of wax.

Some factors are beyond the control of an ordinary recreational skier. Others, such as choosing the correct kick wax, are at least theoretically within everyone's reach.

So what do we actually need for a reliable kick?

≈

SKI GLIDE PHYSICS · RESEARCH SERIES

Why Ski Base Matters

PART 2 OF 2

Why Ski Base Matters – Part No. 2

What Actually Touches the Snow?

At the very beginning of sliding, assuming a freshly prepared and fully waxed ski base, the ski-base material itself may have little or no direct contact with the snow.

Instead, the initial contact takes place primarily between the snow surface and the additionally applied wax and coating layers. During the first several hundred metres, the outermost contact material may be a topcoat or a so-called speeder.

≈

SKI GLIDE PHYSICS · RESEARCH SERIES

Why Ski Base Matters

PART 1 OF 2

Why Ski Base Matters – Part No. 1

If ski waxes and surface coatings worked exactly as they are often presented to work—that is, if they formed a continuous layer covering the entire ski-base surface, regardless of how complex the structure pattern is, and if this layer survived for several tens of kilometres—then the ski-base material itself should matter very little during a race.

Under such conditions, the ski base should hardly ever come into direct contact with the snow. The actual sliding interface would be formed primarily between the snow surface and the wax/coating layer.

In reality, however, the sliding interface and the associated wear processes are considerably more complex.

Liquid Ski Gliders: Wax Base vs. ISANTIN Coating – Glide Performance and Durability

We tested more complex liquid gliders called also as top coats or speeders on ISANTIN coating and we compared liquid glider’s gliding performance and stability if applied both on recommended wax base or ISANTIN coating.

Key Findings

We compared the glide performance and durability of complex liquid gliders applied over two different base layers: a conventional wax base and an ISANTIN coating.

Ski Wax Removal: Three Wax Reservoirs and Brushing – Part 5

☰

WAXING & SURFACE TREATMENTS · RESEARCH SERIES

Wax Layers & Ski Base Preparation

PART 5 OF 5

 1.11 The Boundaries Between the Individual Reservoirs Are Not Sharp

The three reservoirs described above form a useful working model, not three perfectly separated layers.

In reality, continuous transitions exist between them.

Wax filling a deeper groove in the ground structure is geometrically located above the polymer surface, but it may simultaneously be retained very strongly by mechanical interlocking.

Ski Wax Reservoirs: Surface Films and UHMWPE Absorption – Part 4

☰

WAXING & SURFACE TREATMENTS · RESEARCH SERIES

Wax Layers & Ski Base Preparation

PART 4 OF 5

 1.8 First Reservoir: The Macroscopic Wax Layer Above the Surface

The first and most clearly visible reservoir consists of wax that remains as a continuous layer above the original ski-base surface after ironing.

Its thickness may be locally relatively high, particularly where a large amount of wax has been applied or where the wax has not been distributed uniformly by the iron.

How Ski Base Additives Affect Wax Absorption and Penetration – Part 3

☰

WAXING & SURFACE TREATMENTS · RESEARCH SERIES

Wax Layers & Ski Base Preparation

PART 3 OF 5

 1.6 Effect of Additives on the Ski Base’s Capacity to Absorb Wax

Various additives and solid lubricants are commonly incorporated into UHMWPE intended for ski bases, including carbon black, graphite, and other carbon-based materials. The use of carbon particles and solid lubricants in ski-base materials is well documented in the technical literature.

How Does UHMWPE Ski Base Material Absorb Wax? – Part 2

☰

WAXING & SURFACE TREATMENTS · RESEARCH SERIES

Wax Layers & Ski Base Preparation

PART 2 OF 5

 1.3 Which Regions Can Absorb Wax

Under normal conditions, wax molecules cannot freely penetrate perfectly ordered crystalline regions of UHMWPE.

In the crystalline phase, polymer chains are tightly packed and there is insufficient free volume between them for the easy diffusion of paraffin-wax molecules. Crystalline regions therefore represent effectively closed or very poorly accessible parts of the material with respect to wax penetration.

Ski Base Structure and Wax Reservoirs – Part 1

☰

WAXING & SURFACE TREATMENTS · RESEARCH SERIES

Wax Layers & Ski Base Preparation

PART 1 OF 5

Hand or Rotary Brush – That Is the Question?

Service People Version – Understanding Ski Wax Layers

Ski waxing is often presented as a relatively straightforward process: apply wax, allow it to cool, scrape off the excess and finish the ski base with a hand brush or a rotary brush.

But what exactly are we removing during scraping and brushing? Where does the wax actually remain? And how do the properties of the ski base material and its structured surface influence the final result?

Rotary vs. Hand Ski Brushes: Wax Removal and Surface Wear – Part 2

▤

SKI PREPARATION · RESEARCH SERIES

Hand or Rotary Brush?

PART II OF II

 3. How a Fine Rotary Steel Brush Removes Wax

3.1. Specific Design of a Rotary Brush

A rotary brush is functionally similar to a hand brush, but its design and mode of action differ substantially.

For SWIX and TOKO brushes, we will assume:

Ski Base Stiffness and Structure Stability on Wet Snow – Part 2

▦

SKI GLIDE PHYSICS · RESEARCH SERIES

Ski Base Material and Structure Quality

PART 2 OF 2

 The Importance of Dimensional Stability in Wet Conditions

Some ski base manufacturers consider dimensional stability to be one of the decisive material properties, particularly for bases intended for warm and wet snow conditions.

In colder conditions, contact occurs predominantly between the ski base and individual ice grains, whose surfaces are covered by a very thin quasi-liquid layer, referred to as the QLL. At the points of actual contact, this layer can act as a highly effective boundary lubricant.

How Ski Base Material Affects Stone Grinding and Structure Quality – Part 1

▦

SKI GLIDE PHYSICS · RESEARCH SERIES

Ski Base Material and Structure Quality

PART 1 OF 2

 Effect of Ski Base Material on Structure Quality

Ski base material affects the quality of a stone-ground structure primarily in two ways:

1.     through the formation of unwanted fibres and hairs during grinding,

2.     through the dimensional stability of the material during machining and subsequent loading.

A conventional racing ski base consists of an ultra-high-molecular-weight polyethylene (UHMWPE) matrix reinforced and modified with functional particles, most commonly carbon black, lamellar graphite and/or graphene.

Can Ski Brushes Reach the Bottom of Structure Grooves? – Part 2

≋

SKI BASE STRUCTURE · RESEARCH SERIES

Ground vs. Functional Structure

PART 2 OF 2

 

Dimensional Relationship Between the Groove and the Brush

The difference between the ground profile and the functional profile is clearly illustrated by the geometric relationship between the groove and the brush fibres.

Consider a symmetrical V-shaped groove with a pitch of 500 micrometres and a depth of 50 micrometres. At half its depth, it is approximately 250 micrometres wide. A steel fibre with a diameter of 120 micrometres corresponds to the groove width at a depth of approximately 38 micrometres. This model deliberately disregards elastic deformation of both the fibre and the wax and therefore represents a rather optimistic estimate of the attainable depth.

Stone-Ground vs. Functional Ski Base Structure – Part 1

≋

SKI BASE STRUCTURE · RESEARCH SERIES

Ground vs. Functional Structure

PART 1 OF 2

 

The Structure That Does Not Actually Exist

A great deal has been written about structures—perhaps so much that it has become difficult to make sense of them. Let us therefore look at them from a different perspective and show that, at least on well-prepared skis, a structure does not actually exist as a separate and unchanging geometric form.

What We Mean by Structure

By structure, we mean a system of grooves of different shapes, pitches and depths ground into the surface of the ski base.

Hand Brushing Ski Wax: How Steel Brushes Work – Part 1

▤

SKI PREPARATION · RESEARCH SERIES

Hand or Rotary Brush?

PART I OF II

Hand or Rotary Brush - That Is the Question?

To understand the fundamental differences between hand brushing and rotary brushing when removing excess wax from the surface of a ski base, we must first describe how wax is deposited on the base and how it interacts with the base material.

1. Three Types of Wax Reservoir in the Ski Base

After hot waxing, the wax is not present on the ski base as a single homogeneous layer. To assess the effect of brushing, it is useful to distinguish three basic reservoirs.