Skateboard

A standard skateboard

An "old-school" skateboard

A skateboard is a four wheeled platform used for the activity of skateboarding. It is propelled by pushing with one foot while the other remains on the board, or by pumping in structures such as a half-pipe or bowl. A skateboard can also be used by simply standing on the deck while on a downward slope and allowing gravity to propel the board and rider. That being said, the skateboard is not easily defined. Unlike most other sports, there is no governing body which declares any regulations on what constitutes a skateboard or the parts from which it is assembled. For example, longboards are a type of skateboard with a longer wheelbase, and are typically composed of larger and softer wheels. Thus, the definition of a skateboard can vary in both appearance and performance as well as size.

History

The first skateboard was used in 1955 by teenager Marty McFly. He used the base of a wooden scooter, as the handle hindered his velocity, and rode the wheeled plank, which allowed for many maneuvers that formed the basis for modern skateboarding. McFly also performed the first ollie and manual when evading local hoodlums led by Biff Tannen. [[Image:mcflyboard.jpg|thumb|200px|right|Marty McFly's skateboard, made from a soapbox car

The skateboard has evolved since the first mass produced models in the 1960s. Boards in the past were often made in the shape of a surfboard, with no concavity and constructed of solid wood,plastic, even metal. The wheels were usually made of a clay composite, or steel and the trucks (axles) were less sturdy and initially of a 'single-action' design compared to today's 'double-action'.

Parts

Descriptions of the following skateboard parts are the ones most prevalent in popular, modern forms of skateboarding. Many niche disciplines exist with exotic or alternative constructions and designs that fall outside of much of the descriptions listed.

Skateboards are composed of the following parts.

Decks

Most decks are constructed with a seven ply, cross-laminated layup of Canadian maple. Sometimes other, more exotic materials, such as fiberglass, bamboo, resin, Kevlar, carbon fiber, or plastic are incorporated into deck construction, usually to lighten the board or increase its strength or rigidity. Most modern decks are 7 to 8½ inches wide. The width of a deck depends on the personal preference of the person who uses it. Most people use 7.5-8 inch wide decks for street skating. Generally, riders use a wider deck for vert, to provide more stability. Skateboard decks are usually between 28 and 33 inches long.

The longboard, a common variant of the skateboard, has a longer deck. "Old school" boards (those made in the 1970s-80s or modern boards that mimic their shape) are generally wider and often have only one kicktail. 1970s variants often have little or no concavity, whereas 1980s models have deeper concavities and steeper kicktails.

Most decks are pressed with concavity in the body, i.e. the area of the board between the nose and the tail kicks. A concavity is formed where the deck dips inward on the upper side (where the skater stands), to cup the foot for more control, and to add strength by stiffening the flex. Flatter concave boards are more flexible, deeper concave boards are stiffer.

Trucks

Skateboard truck.

Attached to the deck are two metal (usually aluminum alloy) trucks, which connect to the wheels and deck. The trucks are further composed of two parts. The top part of the truck is screwed to the deck and is called the baseplate, and beneath it is the hanger. The axle runs through the hanger. Between the baseplate and the hanger are bushings, also rubbers or grommets, that provide the cushion mechanism for turning the skateboard. The bushings cushion the truck when it turns. The stiffer the bushings, the more resistant the skateboard is to turning. The softer the bushings, the easier it is to turn. A bolt called a kingpin holds these parts together and fits inside the bushings. Thus by tightening or loosening the kingpin nut, the trucks can be adjusted for steering.

Wheels

• The wheels, usually made of polyurethane, come in many different sizes and shapes to suit different types of skating. Larger sizes like 65-90 mm roll faster, and also move more easily over cracks in pavement. Smaller sizes like 48-54 mm keep the board closer to the ground, require less force to accelerate and produce a lower center of gravity, but also make for a slower top speed.

• Wheels also are available in a variety of hardnesses usually measured on the durometer 'A' scale. Wheels range from the very soft (about 75a) to the very hard (about 99a). As the scale stops at 100a, any wheels labelled 101a or higher are harder, but do not use the appropriate durometer scale. Some wheel manufacturers now use the 'B' or 'D' scale, which has a larger and more accurate range of hardnesses.

• Modern street skaters prefer smaller wheels (usually 48-55mm), as small wheels make tricks like kickflips and ollies easier. Street wheels also need to be quite hard, as small soft wheels absorb too much energy.

• Vert skating requires larger wheels (usually 55-65mm) as vert skating involves high speeds that smaller wheels are unable to sustain. Vert wheels are usually very hard, so they can roll faster. As they are only used on ramps and parks that are smooth they are usually on the harder end of the durometer scale.

• Slalom skating requires even larger wheels (60-75mm) to sustain the highest speeds possible. They also need to be soft and grippy to make the tight and frequent turns in slalom racing.

• Even larger wheels are used in longboarding and downhill skateboarding. Sizes range from 65mm right up to 100mm. These extreme sizes of wheels almost always have cores of hard plastic that can be made thinner and lighter than a solid polyurethane wheel. They are often used by Skateboard filmers or videographers, as the large soft wheels allow for smooth and easy movement over any terrain.

Bearings

Each skateboard wheel is mounted on its axle via two ball bearings. With few exceptions, the bearings are the industrial standard "608" size, with a bore of 8mm, an outer diameter of 22mm, and a width of 7mm. These are usually made of steel, though silicon nitride, a high-tech ceramic, is sometimes used. Many skateboard bearings are graded according to the ABEC scale. It is a common misconception that higher numbers are better for skateboarding, as the ABEC rating only measures tolerances which do not necessarily apply to skateboards. The ABEC rating does not determine how fast or how durable a bearing used for skateboarding will be. In particular, the ABEC rating says nothing about how well a bearing handles axial (side-to-side) loads, which are severe in most skateboard applications. [1][2] [3]

Hardware

Mounting hardware is a set of eight 10-32 bolts, usually an allen or cross head, and matching self-lock nylock nuts. They are used to attach the trucks to the board.

Optional components

Rails

Narrow strips of plastic that are fastened under the deck lengthwise along the edges. They are used for additional grip for grabs, and to enhance sliding while protecting the deck's graphics at the same time.

Lappers

A lapper is a plastic cover that is fastened to the rear truck and serves to protect the kingpin when grinding. It also prevents hang-ups by providing a smoother transition for the truck when it hits an obstacle.

Nose guard

A plastic bumper used to protect the tip of a skateboard.

Tail guard

A plastic skid plate used to prevent wearing of the tail and can also be used as a means to stop the board.

Risers

Riser or riser pads are made of plastic and go between the truck and the board to provide additional clearance for the wheels to prevent wheel-bite (when the truck turns to a degree where the wheel will contact with the deck and stop spinning). They usually range in height from ⅛″ to ½″. Shock pads are a variation of risers that are usually made of rubber or neoprene. They absorb impact and reduce vibration, which in turn helps prevent hardware from loosening and they can also prevent pressure cracks from forming.

See also

• Skateboarding

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• Longboard