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Fakie
This is a skateboarding related list that defines everything, maneuver, venue, and physics terms that are important to skateboarding. These terms are commonly used in the vocabulary of a skateboarder in order to reference specific parts, tricks, and locations efficiently. Anatomy of a skateboard A skateboard is made up of many parts both movable and immovable that when put together allow a rider to propel him or herself forward and steer left or right. A skateboard is propelled by pushing with one foot while the other remains on the board, or by pumping in structures such as a pool or half-pipe. A skateboard can also be used by simply standing on the board while on a downward slope and allowing gravity to propel the board and rider. Board parts *Hardware: Nuts, bolts, and screws that hold the trucks, bushings, and base plate onto the board. *Board: Also known as the Deck or Shape, this is the main part of a skateboard, the portion that is used to skate on. Boards are typic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ollie (skateboarding Trick)
The ollie is a skateboarding trick where the rider and board leap into the air without the use of the rider's hands. It is the combination of stomping (also known as popping) the tail of the skateboard off the ground to get the board mostly vertical, jumping, and sliding the front foot forward to level out the skateboard at the peak of the jump. The ollie is a fundamental skill in skateboarding. Ollies are necessary to leap onto, over, or off of obstacles. As most flip tricks depend on it, the ollie is often the first skill to be learned by a new skateboarder and typically takes considerable practice to master. Origin of the technique In 1978, Alan Gelfand, who was given his nickname "Ollie" by Scott Goodman, learned to perform frontside no-handed aerials in bowls and pools using a gentle raising of the nose and scooping motion to keep the board with the feet. There are numerous references to Alan Gelfand's ollie, most notably pictures in the 1970s skateboarding magazine ''Skate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skateboarding
Skateboarding is an extreme sport, action sport that involves riding and Skateboarding trick, performing tricks using a skateboard, as well as a recreational activity, an art form, an entertainment industry Profession, job, and a method of transportation. Originating in the United States, skateboarding has been shaped and influenced by many skateboarders throughout the years. A 2009 report found that the skateboarding market is worth an estimated $4.8 billion in annual revenue, with 11.08 million active skateboarders in the world. In 2016, it was announced that skateboarding would be represented at the 2020 Summer Olympics in Tokyo, for both male and female teams. Skateboarding made its Olympic debut in 2020 and was included in the 2024 games. Since the 1970s, skateparks have been constructed specifically for use by skateboarders, freestyle BMXers, aggressive inline skating, aggressive skaters, and more recently, Freestyle scootering, scooters. However, skateboarding has becom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheelbase
In both road and rail vehicles, the wheelbase is the horizontal distance between the centers of the front and rear wheels. For road vehicles with more than two axles (e.g. some trucks), the wheelbase is the distance between the steering (front) axle and the centerpoint of the driving axle group. In the case of a tri-axle truck, the wheelbase would be the distance between the steering axle and a point midway between the two rear axles. Vehicles The wheelbase of a vehicle equals the distance between its front and rear wheels. At equilibrium, the total torque of the forces acting on a vehicle is zero. Therefore, the wheelbase is related to the force on each pair of tires by the following formula: :F_f = mg :F_r = mg where F_f is the force on the front tires, F_r is the force on the rear tires, L is the wheelbase, d_r is the distance from the center of mass (CM) to the rear wheels, d_f is the distance from the center of mass to the front wheels (d_f + d_r = L), m is the mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alan Gelfand
Alan "Ollie" Gelfand (born April 30, 1963) is an American skateboarder, racing driver, and businessman credited with inventing the Ollie (skateboarding), ollie, the foundational skateboarding trick. Early life Alan Gelfand was born in New York City, and is Jewish. Gelfand moved to Hollywood, Florida with his family in 1972. He started skateboarding in 1974 after his father bought him his first skateboard. Skateboarding career Invention of the ollie Named by Thrasher (magazine), Thrasher Magazine as "The Founding Father of A Generation", Alan Gelfand's invention of the ollie changed the face of skateboarding. His initial performance of the trick in 1976 at Skateboard USA in Hollywood, Florida, was serendipitous, stemming from the imperfect construction of the skatepark itself. Gelfand explained that the park's poorly constructed features inadvertently led to his groundbreaking discovery. "It was all by accident. The park was built so poorly that many of the features were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delrin
Polyoxymethylene (POM), also known as acetal, polyacetal, and polyformaldehyde, is an engineering thermoplastic used in precision parts requiring high stiffness, low friction, and excellent dimensional stability. Short-chained POM (chain length between 8 and 100 repeating units) is also better known as paraformaldehyde (PFA). As with many other synthetic polymers, polyoxymethylenes are produced by different chemical firms with slightly different formulas and sold as Delrin, Kocetal, Ultraform, Celcon, Ramtal, Duracon, Kepital, Polypenco, Tenac and Hostaform. POM is characterized by its high strength, hardness and rigidity to −40 °C. POM is intrinsically opaque white because of its high crystalline composition but can be produced in a variety of colors. POM has a density of 1.410–1.420g/cm3. Typical applications for injection molding, injection-molded POM include high-performance engineering components such as small gear wheels, Glasses, eyeglass frames, ball bearings, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball Bearing
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling, they have a much lower coefficient of friction than if two flat surfaces were sliding against each other. Ball bearings tend to have lower load capacity for their size than other kinds of rolling-element bearings due to the smaller contact area between the balls and races. However, they can tolerate some misalignment of the inner and outer races. Common ball bearing designs include ''angular contact, axial, deep-groove,'' an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABEC Scale
The ABEC scale is an industry accepted standard for the tolerances of a ball bearing. The ABEC scale is designed to provide bearing manufacturers dimensional specifications that meet the standards of precision bearings in a specified class. The scale is also used by manufacturers who produce equipment that require bearings must also know the dimensional tolerances to design parts that will accommodate a bearing. History It was developed by the Annular Bearing Engineering Committee (ABEC) of the American Bearing Manufacturers Association (ABMA). Tolerance classes There are five classes, which are named using the first five odd numbers: * 1 (widest tolerance) * 3 * 5 * 7 * 9 (tightest tolerance) The naming scheme is inverse with the tolerance, i.e. higher numbers mean lower tolerance. The higher ABEC classes (lower tolerance) provide better precision, efficiency, and the possibility of greater speed capabilities, but do not necessarily allow the components to spin faster. Bea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolling-element Bearing
In mechanical engineering, a rolling-element bearing, also known as a rolling bearing,ISO 15 is a bearing (mechanical), bearing which carries a load by placing rolling elements (such as balls, cylinders, or cones) between two concentric, Groove (engineering), grooved rings called Race (bearing), races. The relative motion of the races causes the rolling elements to rolling, roll with very little rolling resistance and with little sliding (motion), sliding. One of the earliest and best-known rolling-element bearings is a set of logs laid on the ground with a large stone block on top. As the stone is pulled, the logs roll along the ground with little sliding friction. As each log comes out the back, it is moved to the front where the block then rolls onto it. It is possible to imitate such a bearing by placing several pens or pencils on a table and placing an item on top of them. See "bearing (mechanical), bearings" for more on the historical development of bearings. A rolling el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearing (mechanical)
A ball bearing A bearing is a machine element that constrains relative motion to only the desired motion and reduces friction between moving parts. The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis; or, it may prevent a motion by controlling the vectors of normal forces that bear on the moving parts. Most bearings facilitate the desired motion by minimizing friction. Bearings are classified broadly according to the type of operation, the motions allowed, or the directions of the loads (forces) applied to the parts. The term "bearing" is derived from the verb " to bear"; a bearing being a machine element that allows one part to bear (i.e., to support) another. The simplest bearings are bearing surfaces, cut or formed into a part, with varying degrees of control over the form, size, roughness, and location of the surface. Other bearings are separate devices installed into a machine or mach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyurethane
Polyurethane (; often abbreviated PUR and PU) is a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane term does not refer to the single type of polymer but a group of polymers. Unlike polyethylene and polystyrene, polyurethanes can be produced from a wide range of starting materials resulting in various polymers within the same group. This chemical variety produces polyurethanes with different chemical structures leading to many List of polyurethane applications, different applications. These include rigid and flexible foams, and coatings, adhesives, Potting (electronics), electrical potting compounds, and fibers such as spandex and polyurethane laminate (PUL). Foams are the largest application accounting for 67% of all polyurethane produced in 2016. A polyurethane is typically produced by reacting a polymeric isocyanate with a polyol. Since a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
