in-line skate

Background

In-line skates were developed in the mid-1980s, but the basic concept of rolling wheels attached to a boot is much older. Earlier roller skates had wheels of wood, plastic, or steel, arranged in pairs. Modernday in-line skates have wheels made out of polyurethane plastic arranged in a line so that the gliding action is much like that of an ice skating blade. Sometimes this type of skate is called a rollerblade, although this is a trademark name and refers only to a specific brand of skates.

History

People in Scandinavia used ice skates as early as 1000 B.C. These skates were made of bone runners tied to boots, and they were used to travel across frozen lakes. The first roller skate is credited to Belgian inventor Joseph Merlin, who in 1760 demonstrated a pair of skates with small metal wheels. A French inventor named Petitbled patented a roller skate in France in 1819 that was some-thing like today's in-line skates. Petitbled's invention had a straight line of wooden, metal, or ivory rollers attached to a wooden sole. Soon after, Robert John Tyers of London came up with what he called the "rolito," a similar skate with five wheels placed in a row on the bottom of a shoe. Roller skates steadily gained in popularity, and the 1849 French opera "La Prophete" even featured a simulated ice skating scene where the performers used wooden-wheeled in-line skates.

These early skates became less common, however, with the 1863 invention of the "rocking skate" by American James Plimpton. Plimpton's skate had a pair of wheels in front and back, mounted on a rubber-padded plate. Roller skaters were able to skate in curves with the Plimpton skate, quite an advantage over previous models. This style of skate soon became the standard. Other innovations were incorporated: high-topped stiff leather boots were attached to metal plates; moveable parts were added to plates to allow skaters to turn corners; and a pair of wheels was attached to an axle on each assembly. Plastic wheels eventually replaced steel or wooden wheels, and basic design improvements over the years have included use of a rubber toe stop, similar to a front brake, and sturdier assembly.

In the 1980s, hockey players Scott and Brennan Olson of Minneapolis, Minnesota, were looking for a way to modify hockey boots so they could cross-train year round. While rummaging through a sporting goods store, they discovered an in-line skate and decided to improve on the design. They began assembling what would be the first "Rollerblade" in-line skate in the basement of their parents' house. The Olsons' first in-line skate had steel frames and skateboard rubber wheels that were riveted to hockey boots. Their prototype was extremely clunky and heavy, but the basic design prevailed.

Hockey players were the first to seriously use in-line skates. During the summer months, they played roller hockey games in the gym and outside on pavement. Nordic and alpine skiers also began to use in-line skates in their training. Soon the popularity of the skates spread to non-athletes as well. Scott Olson created the company that became Rollerblade, Inc. and improved on several of the in-line skate patents. But competition from other in-line skate manufacturers forced the company to adopt even more sophisticated manufacturing and marketing efforts. In 1994, Rollerblade patented the Active Brake Technology (ABT) braking system, a cuff-activated braking system that made stopping easier for beginning in-line skaters. The new brake also provides greater speed control. Rollerblade currently holds 16 U.S. patents and 200 pending patents for in-line skating products.

Parts of In-Line Skates

The modern in-line skate has polyurethane wheels aligned on a strip or truck (chassis) made out of plastic or light aluminum. The truck holds the wheels in place with bolts, and on some models the wheels can be detached and changed. The truck is attached to a molded boot, also made of polyurethane, which holds the buckles (made out of plastic, velcro straps, or cloth laces). Some in-line boot shells are leather or a combination of leather and polyurethane plastic. The brakes are made of hard rubber or polyurethane and are located on the back of the skate.

The boots are designed to provide good ankle support by extending 3-4 inches (7-10 cm) above the ankle joint. The upper and lower portions of the boot are connected on each side of the ankle by a hinge system that allows the ankle to flex. For additional comfort, boots are lined with material that absorbs sweat, usually high-density foam covered with nylon clots. Wheels vary in hardness (durometer) and size (diameter). Generally, the harder the wheels, the faster the skates. Wheels have two ball bearings per wheel that are separated by a spacer of either plastic or metal. Bearings help the wheels spin faster and more freely. The spacer helps prevent the bearings from making contact with each other.

Raw Materials

The in-line skate is a product of modern technology. High-grade polyurethane, copolymer plastics, or carbon fiber Kevlar (material used to make bulletproof vests) are used to make the majority of in-line skating shells or boots. Wheels are also made of polyurethane. Harder nylon or urethane plastic or steel is used for the chassis and brake components. Frames that hold the wheels can be made of aluminum, carbon fiber, or titanium. Cloth or plastic foam is used to line the inside of the boot. Steel is also used for ball bearings, buckles, and other attachments on the in-line skate itself.

The Manufacturing
Process

Separate companies worldwide manufacture the individual in-line skate components. For example, manufacturers of skate-board wheels also make in-line skate wheels. Another company makes the boot shell and chassis; another manufacturer provides the braking system. In-line skates are manufactured using an assembly line process whereby all components move down a conveyor belt and are assembled piece by piece.

Making the boot shell

• In-line boot shells are made by a process called injection molding. Urethane plastic is injected into a mold to form the boot shell, much like a ski boot. Dye may be added for color. When the mold has cooled, the injection-molding machine ejects the finished boot.

Inserting the liner

• Soft cloth or plastic foam is cut to various sizes and inserted into the boot shell. The dimensions of the liner should conform to the skater's foot.

Adding the attachments

• The remaining shell cuff (as well as the tongue), metal buckles, and plastic or velcro fasteners are attached to the shell. Most of these pieces are bought prefabricated.

Assembling the wheels

• The frame, including wheels and bearings, is attached to the boot shell by rivets or by a coupling system. The frame is often assembled ahead of time. The wheels are placed in a row and attached to the frame. On inexpensive models, the boot and frame are injection molded as one unit.
• Once the in-line skate has been assembled, it is boxed and delivered to stores.

The Future

In 1990, Rollerblade reported retail sales of more than $100 million and in 1991 controlled about 70% of the in-line skating market. Ultra-Wheels claims about 20% of the market. Since its heyday, however, Rollerblade has lost market share to many competitors, an indication of the widespread popularity of in-line skates. Industry analysts have predicted that the market for in-line skates could reach $1 billion in 1995, compared to $200 million in 1992. The future for the product is highly favorable and newer models that are faster, lighter, and more comfortable are being developed every year.

Where To Learn More

Books

Powell, Mark and John Svensson. In-Line Skating. Human Kinetics Publishers, 1993.

Rappelfeld, Joel. The Complete Blader. St. Martin's Press, 1992.

Periodicals

Fassett, Wayne. "Blade Runners." Popular Mechanics, November 1991, p. 49.

Macnow, Glen. "New Ideas Get a Sporting Chance." Nation's Business, December 1992, pp. 62-63.

"Synergy Standouts." Sporting Goods Business, February 1994, p. 74.

[Article by: Evelyn S. Dorman]

The noun has one meaning:

Meaning #1: a shoe with rollers fixed to the sole in a line
  Synonym: roller blade

'Inline skates' (often called Rollerblades after the popular trade name) are a type of roller skate used for inline skating. Unlike quad skates, which are configured with two front and two rear wheels, inline skates have two, three, four or five wheels arranged in a single line. Some inline skates, especially those used for recreation, have a "stop" or "brake" which is used to slow down while skating; most inline skates have a heel stop rather than the toe stop, particularly indispensable for inline figure skating.

The modern style of inline skates were developed as a substitute for ice skates, for use by a Russian athlete training on solid ground for Olympic long track speed skating events. Life magazine published a photo of American skater Eric Heiden, training for the 1980 Olympics, using such skates on a Wisconsin road.^[1]

During the late 1980s and early 1990s, Rollerblade, Inc., a company founded by Scott and Brennan Olson in Minneapolis, Minnesota, widely promoted inline skating; they were so successful that their trademarked name Rollerblade became synonymous with inline skates.^[2]

Contents 1 Parts 1.1 The boot 1.2 The frame 1.3 Bearings 1.4 Wheels 2 Brakes 3 Notes 4 See also 5 External links

Parts

A skate is composed of a boot, which is worn on the foot. To the boot is attached a frame, which holds the wheels in place. Bearings allow the wheels to rotate freely around an axle. Finally, the rubber brake typically attaches to the frame of the right foot.

An inline skate designed for artistic roller skating

There are different types of inline skates for different types of skating such as aggressive skating, speed skating, Inline hockey and artistic inline skating. Those differ in the boots, frames and wheels that are used.

The boot

For most skating a high boot is used, which provides more ankle support and is easier to skate in, particularly for beginners. Speed skaters often use a carbon fiber boot which provides greater support with a lower cut allowing more ankle flexion. For recreational skating a soft boot is used for greater comfort, but many other disciplines prefer a harder boot, either to protect the foot against impact or for better control of the skate. The boot may also contain shock absorbent padding for comfort.

Most aggressive skates use a hard boot or a hard/soft boot for increased support.

The frame

The frame and wheels of an inline skate.

Typical recreational skates use frames built out of high-grade polyurethane (plastic). Low-end department or toy store skate frames may be composed of other types of plastic. Speed skate frames are usually built out of carbon fibre or extruded aluminum (more expensive but more solid), magnesium, or even pressed aluminum, which is then folded into a frame (cheaper but less sturdy).

Carbon fibre frames are expensive but more flexible, making for a smoother ride at the expense of worse power transfer between the leg and the wheels. In general, carbon fibre frames weigh about 160-180 grams. Aluminum can weigh from 170 to 220 grams. Frame length ranges from around 230 mm for short-framed four wheel skates (used for example in inline hockey), up to about 325 mm for a five wheel racing frame.

Bearings

Axles, bearings and spacers.

Ball bearings allow the wheels to rotate freely and smoothly. Bearings are usually rated on the ABEC scale, a measure of the manufactured precision tolerance, ranging from 1 (worst) to 9 (best) in odd numbers. The ABEC standards were originally intended for high-speed machinery, not skating applications, and do not account for the quality of steel used, which is also important. While higher rated bearings are generally better in overall quality, whether they automatically translate to more speed is questionable^[3].

The vast majority of skate bearings on the market are produced in China, and tend to be of much lower quality and durability than bearings produced in Canada, Germany, Japan, Switzerland, or the USA. Newer bearings on the market now use ceramic ball bearings instead of steel, the merits of which have yet to be determined.^{[citation needed]}

Wheels

Diagram of inline skate wheels with different diameters and profiles.

Wheel sizes vary depending on the skating style:

• 44–59 mm for aggressive skating.
• 68–72 mm for artistic inline skating.
• 47–80 mm for roller hockey skating.
• 72–80 mm for freestyle slalom skating.
• 72–90 mm for general recreational skating.
• 84–110 mm for speed skating.

Wheels are nowadays almost universally made of polyurethane (a kind of durable plastic). Most other plastics and rubber either wear down too quickly or have too much roll resistance. In general, the bigger the wheel, the faster the skate^{[citation needed]} . However, large wheels take more energy to start rolling. Smaller wheels allow faster acceleration, maneuverability, and a lower center of gravity. Wheel hardness is measured on the A scale (see Durometer) and usually ranges between 78A-93A (higher numbers are harder). Harder wheels are faster and more durable, but soft wheels may have better grip (grip is determined by many factors, and wheel manufacture is arguably more important than durometer) and less affected by road bumps. Wheel profiles and thicknesses again vary by application. Elliptic profiles minimise friction for a faster ride; more rounded profiles have better grip and are more stable.

Brakes

A brake allows the skater to stop by moving his foot. A hard rubber brake is typically attached to the heel of the frame. Learning how to use the heel brake thus is crucial for beginners.

Heel brakes can interfere with a useful technique called crossover turn, in which a skater crosses one leg over another to make a sharp turn without losing much speed; for this reason, some users prefer not to use heel brakes. Skaters in the freestyle slalom and Aggressive inline skating disciplines also tend not to use heel brakes, since they can limit the skater's ability to perform tricks effectively. Most aggressive inline skates and racing skates do not have a heel brake for extra speed and control, people wearing inline skates with no heel brake can use various other methods to stop, such as the T-Stop in which the skater moves one skate perpendicular to the other, making a "T" shape to increase friction and slow the rider down.

Notes

1. ^ Whittingham, Richard, LIFE In sports, Harper & Row, pp. 236–237 
2. ^ Lemelson-MIT (August 1997). "Inventor of the Week Archive: Scott & Brennan Olson (spelling corrected per rowbike.com -ed.)". MIT School of Engineering 2.In 1995 the Pic skate, utilizing a toe brake, was invented by sporting good designer John Petell of West Springfield, Massachusetts and Nicolas Perna master rated figure skating coach of Fairfax, Virgina. The invention, patented in 1998 is the bases for the new sport of inline figure skating. The key lesson derived from the invention is the correct angle between the pic (toe brake) and the skating surface which enables one to perform virtually all ice skating moves: jumps, spins, and footwork moves normally associated with ice figure skating. One unique feature of the Pic skate is that it allows for stops while skating in reverse. The Pic skate has been found in a survey to be 2.3 times easier to use than conventional heel brake skates. Inline figure skating clubs have formed in France,Spain,Greece, and several other countries to participate in this emerging sport. The 5th annual Paris Open is scheduled for January 2010. Skaters from several countries are expected to compete. The Pic skate has also been tested for hockey as well as an all purpose skate with very positive results. A gym skate program has been developed to teach beginning skating in schools. In a survey the. http://web.mit.edu/invent/iow/Inline.html. Retrieved 2007-02-25. 
3. ^ ABEC = HYPE?

See also

• Inline skate wheel setups

External links

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