A skateboard is a type of sports equipment used primarily for the activity of skateboarding. It usually consists of a specially designed maplewood board combined with a polyurethane coating used for making smoother slides and stronger durability.
A skateboard is propelled by pushing with one foot while the other remains on the board, or by pumping one's legs in structures such as a bowl or half pipe. 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. If the rider positions their right foot forward, he/she is said to ride "goofy;" if the rider positions their left foot forward, he/she is said to ride "regular." If the rider is normally regular but chooses to ride goofy, he/she is said to be riding in "switch," and vice versa. A skater is typically more comfortable pushing with their back foot; choosing to push with the front foot is commonly referred to as riding "mongo".
Recently, electric skateboards have also appeared. These no longer require the propelling of the skateboard by means of the feet; rather an electric motor propels the board, fed by an electric battery.
There is no governing body that declares any regulations on what constitutes a skateboard or the parts from which it is assembled. Historically, the skateboard has conformed both to contemporary trends and to the ever-evolving array of stunts performed by riders/users, who require a certain functionality from the board. Of course, the board shape depends largely upon its desired function. Longboards are a type of skateboard with a longer wheelbase and larger, softer wheels.
Skateboards have three axes. The tail axis (running from nose to tail), the central axis (running straight down through the center of the board), and the short axis (running from the width of the board, perpendicular to the tail axis).
The two main types of skateboards are the longboard and the shortboard. The shape of the board is also important: the skateboard must be concave to perform difficult tricks.
The following descriptions cover skateboard parts that are most prevalent in popular, modern forms of skateboarding. Many parts exist with exotic or alternative constructions. A traditional complete skateboard consists of the deck (often with griptape applied on top to enhance traction), trucks (with urethane bushings), wheels (with sealed bearings), bushings and nuts and bolts to fasten the truck and wheel assembly to the bottom of the deck. Older decks also included plastic parts such as side, tail, and nose guards.
The side of a skateboard
Modern decks vary in size, but most are 7 to 10.5 inches (17.78 to 26.67 centimeters) wide. Wider decks can be used for greater stability when transition or ramp skating. Skateboard decks are usually between 28 and 33 inches (71.12 and 83.82 centimetres) long. The underside of the deck can be printed with a design by the manufacturer, blank, or decorated by any other means.
The longboard, a common variant of the skateboard, has a longer deck. One of the first deck companies was called "Drapped" taken from Jonny's second name. "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. Variants of the 1970s often have little or no concavity, whereas 1980s models have deeper concavities and steeper kicktails.
Grip tape is a sheet of paper or fabric with adhesive on one side and a surface similar to fine sand paper on the other. Grip tape is applied to the top surface of a board to allow the rider's feet to grip the surface and help the skater stay on the board while doing tricks. Grip tape is usually black, but is also available in many different colors such as pink, yellow, checkered, camo, and even clear. Often, they have designs die-cut to show the color of the board, or to display the board's company logo.
An Independent brand skateboard truck
Attached to the deck are two metal (usually aluminum alloy) trucks, which connect the wheels and bearings to the 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 rubbersor 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 loosely for better turning and tighter for more stability. Standard kingpin nut size is 3/8" - 24tpi.
Skateboard trucks are manufactured in a number of different axle widths. In general an axle width should be chosen that is close to the width of the deck it will be used with. For example, a 7.75" wide deck will usually be fitted with trucks that have axles between 7.5" wide and 8.0" wide. (Standard truck axle nut size is 5/16"-24tpi UNF, and the thinner "jam" style with an optional nylon lock.) Trucks that are too wide can make doing tricks difficult and can cause the wheels to get in the way when the skateboard is being ridden. Trucks that are too small can be hard to maintain stability and can cause wheel bite to occur when turning.
Longboard-specific trucks are a more recent development. A longboard truck has the king pin laid at a more obtuse angle (usually between 38 and 50 degrees) to the deck, this gives a greater degree of turning for the same tilt of the deck. This allows riders to go much faster while still maintaining stability and control.
The wheels of a skateboard, usually made of polyurethane, come in many different sizes and shapes to suit different types of skating. Larger sizes like 55–85 mm roll faster, and move more easily over cracks in pavement and are better for transition skateboarding. 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 and are better for street skateboarding. Wheels also are available in a variety of hardnesses usually measured on the Shore durometer "A" scale.. Wheels range from the very soft (about Shore A 75) to the very hard (about Shore A 101). As the A scale stops at 100, any wheels labeled 101A or higher are harder, but do not use the appropriate durometer scale. Some wheel manufacturers now use the "B" or "D" scales, which have a larger and more accurate range of hardness. Modern street skaters prefer medium sized wheels (usually 51–54 mm), as small wheels with lighter trucks can make tricks like kickflips and other flip tricks easier by keeping the center of gravity of the skateboard closer to the deck, thus making the deck easier to spin. Street wheels are harder (A 100/A 101). Vertical ramp or "vert" skating requires larger wheels (usually 55–65 mm), as it involves higher speeds. Vert wheels are also usually slightly softer (A 98/ A 99), allowing them to maintain high speed on ramps without sliding. Slalom skating requires even larger wheels (60–75 mm) to sustain the highest speeds possible. They also need to be soft and have better grip to make the tight and frequent turns in slalom racing. Even larger wheels are used in longboarding and downhill skateboarding. Sizes range from 65 mm to 100 mm. 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 videographers as well, as the large soft wheels allow for smooth and easy movement over any terrain.
An animation of the working principle for aball bearing.N.B. The diagram shows an 8-balled-bearing whereas a skateboard bearing is typically 7-balled
Each skateboard wheel is mounted on its axle via two bearings. With few exceptions, the bearings are the industrial standard "608" size, with a bore of 8 mm, an outer diameter of 22 mm, and a width of 7 mm. 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. The scale starts with ABEC1 as the lowest, 3, 5, 7, 9. It is a common misconception that the higher ABECs are better for skateboarding, as the ABEC rating only measures tolerances, which do not necessarily apply to skateboards. Bearing performance is determined on how well maintained the bearings are. Maintenance on bearings includes periodically cleaning and lubricating them. Bearings that are kept unmaintained have their performance greatly lowered and will soon need to be replaced. Bearing cleaning kits are commonly available on the market. 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. Many companies do not show the ABEC rating, such as Bones Bearings, which makes bearings specifically for skateboarding, often marketed as "Skate Rated". Each bearing usually contains 7 steel or ceramic ball bearings, although other configurations are used as well.
Mounting hardware is a set of eight 10-32 UNF bolts, usually an Allen or Phillips head, and matching nylon locknuts. They are used to attach the trucks to the board. Some sets have one different colored bolt to show which side is the nose of the skateboard. Hardware is available in various lengths for mounting trucks with or without risers.