SNOWBOARDING

SNOWBOARD CONSTRUCTION

Each manufacturer has slightly different methods to making snowboards, but the basic structure stays very similar. The basic structure of a snowboard with a wood core is shown in the graphic below, with each part explained in detail further down the page.

Sidewall Construction

The sidewall is the area along the edge of a snowboard, and will generally be one of 3 types of construction, depending on how the ends of the different layers have been finished.

ABS Sidewall / Sandwich Construction - Where each layer of the snowboard is laid flat and an ABS sidewall is put in at the sides to protect the core. This design is good for freeriding as it transmits pressure to the edges well.

Cap Construction - The fibreglass layer and topsheet are brought down over the core to seal the edge. This design makes the board a bit lighter and gives a bit of extra snap, but it is not found on snowboards so often any more.

Half-Cap Construction - A hybrid of the other 2 constructions where the fibreglass layer comes down around the core, and the topsheet comes part way around to join a sidewall. This design provides good pressure transmission to the edges, and is reasonably light and snappy. It is normally found on higher end snowboards.

Quite often a hybrid-cap construction will be found on boards, with the board having an ABS sidewall along the middle of the board, turning into a cap construction at the tips.

The sidewalls that are added are generally made of ABS plastic, but often have layers of rubber underneath it to help absorb shocks, and can also have layers of other materials like aluminium, and bamboo.

The Core

The core is the central structure of a snowboard, which determines a lot of a snowboard's characteristics. This is where the main strength of a snowboard lies, and is seen as the part the snowboard to which everything else is attached to.

Core Materials

Most snowboard cores are made of strips of laminated hardwood like beech, birch, aspen, bamboo, or a mixture of them. Wood is used as it gives a lively feel with good vibration damping, it keeps its shape well, and has less resonance than foam or plastic.

Many other materials can also be used for or in the core though, including:

  • Carbon - Light, lively, strong and very good under compression, but very expensive.
  • Kevlar - Strong, reasonably light, good under tension, and a good dampener.
  • Aluminium Honeycomb - Very light and strong, but is expensive and has reduced damping capabilities.
  • Foam - Not used as the main material so often anymore as boards tended to lose their camber quickly and were a bit soft, lacking performance. Foam is often found in low stress areas of some cores to save weight.

Core Construction

Wood cores are made of strips of laminated hardwood that run along the length of the board. The strips used can be made of different woods, arranged in different patterns, and have areas that use other materials like foam. This is done to give different strengths, flexes, and weights to different areas of a snowboard, creating different properties and characteristics. The laminated wood strips are glued together and then precisely CNC machine cut into shape. Carbon fibre rods, and many other materials/structures are often stuck to the core as well to further enhance the desired board characteristics.

Fibreglass Layers

The fibreglass layers are there to help increase board stiffness and stop the board from deforming. There are 2 general ways in which the fibreglass is structured in the layers surrounding the core:

  • Bi-axial wrap - In bi-axial wraps the glassfibre strands are weaved together at 90° to each other, this produces a lightweight, dependable and forgiving layer.
  • Tri-axial wrap - In tri-axial wraps the glassfibre strands are weaved at +45°, 0° and -45°, this again produces a lightweight, dependable and forgiving layer but with increased torsional stiffness and response compare to the bi-axial wrap.

The glassfibre sheets are impregnated with resin, which holds the them together and gives them their strength.

Top Sheet

The topsheet is the part of the snowboard that you see on the top, this is where the graphics are, and is the protection for the inner parts of the snowboard. Topsheets can be made of many different materials including nylon, wood, fibreglass, plastic and composites.

There are 2 main ways in which the graphics can be put on a snowboard:

  • Encapsulation - Where the graphics are printed onto paper, cloth or a similar material and put under a clear top sheet, or clear lacquer on the topsheet. This leaves the graphics under or inside the topsheet, but able to be seen through the topsheet material. The materials and inks used are chosen carefully, otherwise they can affect the bond between the topsheet and the fibreglass underneath.
  • Sublimation - Where the graphics are fused into the materials that make the topsheet using special inks, suitable plastics and heat. This leaves the graphics as part of the topsheet, going all the way through the material so that even if it gets scratched the graphics will still be there.

Base Materials

Bases are made of P-Tex a polyethylene plastic. Most base materials will be followed by a number (i.e. sintered 2000). This number refers to the molecular weight of the polyethylene. The higher the number means the higher the molecular weight, which indicates a better and more durable base.

There are 2 types of base, extruded and sintered:

  • Extruded - This is where the base material is melted and then cut into shape. Extruded bases are cheap to make and low maintenance, but are less durable, and slower. They are smoother and less porous so don't absorb so much wax, but if the base is left unwaxed overall performance is not effected so much.
  • Sintered - This is where the base material is ground into powder, heated, pressed and sliced into shape. Sintered bases are more expensive to make, but are more durable and faster. They are very porous and absorb wax well, but will lose performance if they are left unwaxed, and are more difficult to repair.

Sintered bases can also have graphite and other materials in them, this makes them even faster and more durable. Graphite is added because it is conductive. As a snowboard slides static charges form between the base and the snow which increases friction. The graphite helps dissipate the static charges reducing friction and making the base faster. Graphite bases can also hold even more wax than normal sintered bases, which again makes them even faster.

The graphics that are put onto bases are generally put there by either printing the graphic inside the snowboard, with a clear base to see through to them, or by having a base made of pieces of different colour P-Tex that are precisely cut by machine to fit together.

Edges

Snowboard edges are made of steel or stainless steel, and are held into the board with T-shaped inserts which are built into them. There are 2 types of edges, full wrap and partial wrap. Full wrap edges go all the way around the snowboard and join at one end, this is the strongest type of edge for a snowboard, although it can be hard to repair if damaged badly. Partial wrap edges are where the edges just run along the sides of the board where they will make contact with the snow. Because there is less metal used this makes a snowboard marginally lighter, but because the continuous shape is lost the edges are not always as strong and it can leave the tips of the snowboard more prone to damage.

Metal Inserts

Metal inserts are stainless steel inserts that are built into a snowboard for the binding holes. Obviously as all the forces a rider puts into a snowboard are going to be transmitted through these inserts, they are very well attached to the snowboard's core.

Resin

All the individual parts of the snowboard are held together with resin. It is very important that the type and amount of resin are correct as this can effect the strength, weight and flex of a snowboard.

Wax

Wax is applied to the base of snowboards so that they create less friction with the snow and can slide faster. The most important features of a wax are; to lower the friction coefficient between the base and the snow as much as possible, to be hard enough that snow crystals will not penetrate the wax and make the base grip the snow, and to repel water.

Types of Wax

There are 2 types of wax, hydrocarbon waxes and fluorocarbon waxes. Hydrocarbon waxes are paraffin based, and are the most common type of wax used. They penetrate the deepest into P-Tex bases and last the longest when applied with a hot waxing iron. Fluorocarbon waxes differ from hydrocarbon waxes in that they are made of carbon molecules with negatively charged fluorine atoms, as a pose to the neutrally charged hydrogen atoms in hydrocarbon waxes. This repels water and dirt better, reducing friction and making fluorocarbon waxes faster. Fluorocarbon waxes are generally only used by racers though, as they are expensive, and require more preparation to use. Normally a snowboard is waxed with a hydrocarbon wax first, and then if a fluorocarbon wax is being used it is applied on top.

Temperature Waxes

Waxes are designed for use with different temperatures of snow. There are many all temperature waxes intended to work in all conditions, but really they are just mid range temperature waxes. The main difference between the waxes for different temperatures is how hard they are. A harder wax creates more friction, so the softest wax possible wants to be used, but the wax still needs to be harder than the snow to stop the base from gripping and increasing friction. Colder snow is harder and requires a harder wax, whereas warmer snow is softer and wetter, and requires a softer wax with more hydrophobic additives to repel water better.

For the average snowboarder an all temperature hydrocarbon wax does the job perfectly well, and will give them a reasonably fast ride in all conditions.

Anti-Static Properties

When a base slides along the snow, static charges are created which increase friction. Having a graphite additive in the wax helps conduct these charges, producing better anti-static properties. This creates less static charges between the base and the snow, and therefore reduces the friction due to static electricity.

On to the Newer Snowboard Concepts page.

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