Inline skates

Inline skates are a type of roller skate, used for inline skating. Unlike quad skates which have a configuration of 2 wheels in the front and 2 wheels in the back, inline skates have two, three, four or five wheels arranged in a single line. Some inline skates have a "stop" or "brake" which is used to slow down while skating; most inline skates have a heel stop rather than a toe stop.

The earliest roller skates were of the inline design, but these were later superseded by quad skates, the design of which made skating curved edges easier. During the late 1980s and early 1990s, the popularity of inline skates had a strong resurgence, led by the company Rollerblade, Inc., who promoted and popularized inlines; their skates became so successful that the term "Rollerblades" has become synonymous with "inline skates", and many people call any form of skating "Rollerblading," although this is an unauthorized genericized trademark.

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. There are different types of inline skates for different types of skating such as aggressive skating, speed skating, 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 lower boots 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.

The frame

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 or extruded aluminum (more expensive but more solid), or even pressed aluminum, which is then folded into a frame (cheaper but less sturdy).

Carbon 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 frames weigh aboutt 160-180 grams. Aluminum can weigh from 170 to 220 grams. Frame flength ranges fromd 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

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 and not skating applications. While higher rated bearings are generally better in overall quality, whether they automatically translate to more speed is still questionable. The quality of the steel used is also very important, but is not rated by the ABEC scale. In any case, the general opinion is that if you have the money or inclination, higher ABECs certainly can't hurt. Note that bearings alone won't make up for poor technique or lack of fitness.

Newer bearings on the market now use ceramic ball bearings instead of steel. The merits of ceramic versus steel are probably still to be determined as well.

Wheels

Wheel sizes vary depending on the skating style:

54-56 mm for aggressive skating
68-72 mm for artistic inline skating
72-80 mm for general recreational skating
59-80 mm for roller hockey skating and slalom
80-110 mm for speed skating

In general the bigger the wheel, the faster the skate. 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-86A (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.

External links

Illustrated History of Inline Skate Design At the US Patent Office
Inline skating safety information from Seattle Children's Hospital

Roller skating | Footwear | Sporting goods

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