Bearings
Skateboard Bearings
Skateboards predominantly use so-called precision ball bearings. Most bearings are manufactured from high-quality bearing steel, with the steel alloy determining the quality of the end product.
ABEC - The Magic Word
ABEC = Annual Bearing Engineers Committee
ABEC is a "tolerance rating" measured in inches. It prescribes minimum and maximum values for tolerances in the bearing's physical dimensions, its precise shape and rotation accuracy, in inches (accuracy class). ABEC ratings 1 to 9 define the allowable mechanical tolerances for the manufacture of ball bearings. For skater's bearings, the exact bore diameter and outside diameter- i.e the accuracy of the inner and outer ring's dimensions- is particularly important. Other ABEC criteria include radial and axial accuracy.
The higher the number, the smaller the tolerance value and the more precise the bearing. Common ABEC ratings are 1, 3, 5, 7 and 9.
608 (The Standard Bearing)
The most common type of bearing is type "608", a single-row, deep-groove radial ball bearing with two fixed or removable shields.
688 (Micro Bearing)
Some speed skaters also use the type "688" Micro Bearing. This bearing is much lighter compared to type 608. A 688 deep-groove ball bearing consists of inner and outer rings, a ball cage and usually 10-11 balls.
Truck
Skateboard Truck
The trucks are 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 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.
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. 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.
Deck
Skateboard Deck
For the mass market can basically distinguished between the two following categories:
Chinamaple
Wheter birch or beech, lumbers are cut and also treated in China.
Most chinamaple boards are cut into 9ply (sheets). After compression each ply is approximately 1.1mm-1.2mm thick. Consequently, a 9ply chinamaple deck is approximately 11mm-12mm thick.
However, there are also different wood qualities. Borders that show heavy dark knots are often used for toy qualities, this way the deckmaker does not have any waste material. High-class chinamaple boards are only produced with good sheet qualities (mostly from the inside of the trunk). They are specially sorted out and are therefore more cost-intensive. In order to reach a higher level of stability, the third and fifth sheet of the 9ply chinamaple board are vertically cut. Here, of course, fractions are made, since the trunk is often turned in one direction (horizontal sheets).
Meanwhile, it is even possible to produce 7ply decks whose flexibility and stability (impact) are in accordance with the tolerances necessary for the deck.
Chinamaple decks weight about 1200g.
The impact for both chinamaple and canadianmaple deck, must always be over 200kg (measured from the top onto the deck). The flexibility must not be below 92kg (the deck is inverted and loaded until it touches the ground), otherwise the deck is too soft. This is also why it is not possible to produce 6ply decks.
Canadianmaple
Imported wood from Canada, which is also used for all Pro Skateboard brands. It is more solid and tougher than chinamaple. The strucutre of the lumber itself is whiter and purer than chinamaple, because the trunks are significantly thicker. For lower quality decks, sheets with knots or slight discolouration may be used.
For fisrt-class desk, top quality sheets are used (Class A). The sheets are almost pure. However, wood is a natural product. It is therefore possible that Class A sheets also have knots on the deck.
Due to their consistency, canadianmaple decks can be produced with 7ply. Per ply the thickness is between 0.9cm and 1.0cm. The third and the fifth ply are also vertically cut. The total weight can vary between 950g and 1.200g, depending on the adhesive used.
Canadianmaple decks are produced using either hotpressed or coldpressed methods.
US branded decks are only produced using the more time-consuming coldpressed method, which takes about four times as long to produce as the hotpressed method. Therefore, their production is more expensive.
Wheels
Skateboard Wheels
The wheels of a skateboard come in many different sizes and shapes to suit different types of skating. Larger sizes like 54–85 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 Shore durometer "A" scale. Wheels range from the very soft (75A) to the very hard (101A). Modern skaters prefer smaller wheels, 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 often quite hard as this allows the wheels to slide easier on waxed surfaces for bluntslides and nose/tailslides. Vertical ramp or "vert" skating requires larger wheels, as it involves higher speeds. Vert wheels are also usually softer, allowing them to maintain high speed on ramps without sliding.