thumb|right|upright=0.8|Recreational skates

thumb|right|Urban skates

Inline skates are boots with wheels arranged in a single line from front to back, allowing one to move in an ice skate-like fashion. Inline skates are a type of roller skate. Inline skates became prominent in the late 1980s with the rise of Rollerblade, and peaked in the late 1990s. The registered trademark Rollerblade has since become a generic trademark: "rollerblading" is now a verb for skating with inline skates, or "rollerblades."

In the 21st century, inline skates come in many varieties, suitable for different types of inline skating activities and sports such as recreational skating, they are typically used to mimic ice skating without the ice — due to its inline design. urban skating, roller hockey, street hockey, speed skating, slalom skating, aggressive skating, vert skating, and artistic inline skating. Inline skaters can be found at traditional roller rinks, street hockey rinks, skateparks, and on urban streets. In cities around the world, skaters organize urban group skates. Paris Friday Night Fever Skate (Randonnée du Vendredi Soir) is renowned for its large crowd size, as well as its iconic +10 mile urban routes. Wednesday Night Skate NYC is its equivalent in New York City, also run by volunteers, albeit smaller in size.

History

The documented history of inline skates dates back to the early 18th century, when enterprising inventors sought to make boots roll on wheels to emulate the gliding of ice blades on dry land. Because these wheeled skates were modeled after ice blades, their wheels were arranged in a single line. Skates were simply assumed to have a single runner, whether it was a steel blade on an ice skate or a row of wheels on a wheeled skate.

Wheeled skates

thumb|right|upright=1.2|First patented wheeled skate - 1819

The first patented wheeled skate was filed in France in 1819 by Charles-Louis Petibled. From that point forward, more patents and documented designs continued to explore wheeled alternatives to ice skates. It was the first double-row skate that allowed beginners to steer easily by simply leaning in the desired direction. Plimpton's invention sparked a rapid rise in roller skate popularity and spread across both sides of the Atlantic, creating a period of "rinkomania" during the 1860s and 1870s. His design also redefined the term "roller skate", which no longer referred to all wheeled skates but became synonymous with the "two-by-two" Plimpton style. Polyurethane offers high elasticity, or wheel rebound, without compromising other properties. This rebound helps convert stride energy into acceleration, benefiting all types of inline skating.

In the early 1980s, Scott Olson similarly repurposed polyurethane wheels from roller skates, shaving down tens of thousands to fit the skates sold by his company, Ole's Innovative Sports – later known as Rollerblade. The same qualities that made polyurethane wheels ideal for skateboarding, such as durability, impact resistance, and a smooth ride, also benefited inline skating. This innovation helped bring inline skating out of obscurity and transform it into a popular outdoor sport during the 1980s.

The visible hub size varies with wheel dimensions and skating discipline. In small aggressive wheels, the hub is just a thin ring housing the bearings. In contrast, racing wheels from the 1990s had hubs taking up nearly half the diameter. By the 2020s, 110 to wheels feature hubs that occupy most of the wheel's diameter.

A wheel's volume grows with the square of its diameter given fixed width. Large solid wheels would be too heavy for inline skating, so designers adopted stroller wheel concepts, using lightweight spoked hubs with interlock rims to hold the tire. These "spoked hubs", or "open cores", have an outer rim connected to the bearing housing by spokes. "Full hubs", or "closed cores", are solid discs with no visible separation. "Semi-open cores" fall in between, with solid discs and small hollows drilled to reduce weight.

Wheel diameter and profile

thumb|right|Common sizes and profiles

Inline skate wheels in the 2020s range from to in "wheel diameter", but the "wheel width" remains standardized at .

"Small" wheels in aggressive skates, typically 55 to in diameter, often have a "flat" contact profile resembling a rounded rectangle like car tires.

Most inline wheels are "medium-sized" with a "round" profile, since skaters often tilt their skates rather than always keeping them fully upright. Many techniques involve edging, or skating on the wheel sides, which requires a consistent contact surface at various angles.

  • The National Museum of Roller Skating - many historical roller and inline skates mentioned in this article are featured in this museum's collections.
  • Skating Book FAQ / Bibliography, part 1 of 2 - a listing of inline skating books published in the heyday of inline skating, in the 1990s. Part 1 includes books on inline skating, roller hockey, and quad skating. TOC from each book is reproduced, along with a short summary of the book.