Editing Inline skates (section)

=== Bearing quality ===

[[File:Inline bearings-ILQ-like Abec 3-TRUE Swiss-Bauer Abec 7 608ZZ-Front n Back-IMG 7406-IMG 7419-FRD.jpg|thumb|right|300px|ILQ-style, Swiss-style, and Sealed ]]

Bearings are commonly rated on the [[ABEC scale]], which measures manufacturing precision tolerances, with ratings ranging from 1 (lowest) to 9 (highest) in odd numbers. Originally developed for high-speed industrial machinery, the ABEC scale does not consider material type, material quality, or durability - factors that significantly impact bearing performance in skates. It also ignores how bearing enclosures respond to dirt, moisture, and other real-world skating conditions. While higher ABEC ratings may indicate better precision, they represent only one of many factors that determine a bearing’s suitability for inline skating.<ref name="powell-svensson-inline-skating"/>{{rp|27–28}}<ref name="usenet-chen-FAQ-abec-hype"/><ref name="powerslide-download-guides-bearings-by-wicked"/><ref name="usenet-chen-FAQ-inline-bearings"/>

ABEC precision ratings do not directly indicate how fast a bearing can safely spin. The actual maximum speed, called the mechanical limiting speed, depends on other factors such as materials, lubrication, load, and operating temperature. Manufacturers typically publish datasheets specifying the limiting speed for each tolerance class. For example, [[SKF]], a Swedish bearing manufacturer, lists a limiting speed of 38,000 RPM for its ABEC 3-rated 608 bearings. That is more than sufficient for inline skating, considering that an average skater cruising on 80mm wheels reaches only about 1,326 RPM, or 3.5% of the limiting speed.{{efn-ua|name=skf-608-bearing-abec-3-limiting-speed|
SKF’s 1,152-page rolling bearings catalog lists a limiting speed of 38,000 RPM for its Explorer-class 608-2Z bearings (pages 135 and 262). These bearings meet ISO 492 Class 6 precision tolerances, which are equivalent to ABEC 3, as noted on pages 7, 36, 248, and 250.<ref name="skf-group-rolling-bearings-1152-pages-2018"/>
}}<ref name="get-rolling-blog-engineer-perspective-on-skating"/>

[[File:Inline bearings-TRUE Swiss-Bones REDS-alike-All components disassembled-IMG 7510-FRD.jpg|thumb|right|300px|Bones Swiss can be disassembled]]

Recognizing the unique demands that skating places on bearings, George Powell of [[Powell Peralta]] collaborated with a Swiss bearing manufacturer in the early 1980s to develop 608 bearings specifically tailored for skateboarding. Unlike conventional 608 bearings designed for electric motors operating in clean environments, these purpose-built bearings were engineered to better withstand multi-directional loads from street skating. The outer-facing side featured a serviceable shield that could be easily pried open with a pin for cleaning, while the inner side was left open, as it sat protected within the wheel hub. Understanding that even high-precision bearings degrade when clogged with dirt, Powell replaced standard metal retainers with molded plastic ones, allowing skaters to easily remove these retainers and clean the balls and raceways. He also formulated a custom lubricant optimized for skating conditions. The result was the launch of '''Bones Swiss''' in 1983, a product that remains a gold standard for both skateboarders and inline skaters to this day.<ref name="bones-bearings-history-by-george-powell"/><ref name="bones-bearings-maintaining-your-bones-bearings"/><ref name="usenet-chen-FAQ-inline-bearings"/><ref name="inmoveskates-roller-skate-bearings"/>

[[File:Inline bearings-TRUE Swiss-Bones REDS-alike-Disassembled-Exploded view-IMG 7518-7520-7526-7528-7533-bg-FRD.png|thumb|right|300px|Structure of a Swiss-style bearing]]

Reputable skate bearing manufacturers generally avoid using ABEC ratings, as they do not reflect the engineering tailored specifically for skating. Instead, bearings are marketed under specialized product lines. For example, Bones Bearings offers models such as Bones Swiss, Bones Swiss Ceramic, Bones REDS®, and Bones Big Balls®. All of these are labeled '''Skate Rated'''™, indicating that every component is designed and tested with the demands of real skating in mind. Powell’s “Swiss” design and engineering has become an unofficial standard in the skating industry, with copycat brands offering bearings labeled '''Swiss''' that mimic the same structure and claimed quality, despite not being manufactured in Switzerland.<ref name="publow-speed-skating-1999"/>{{rp|317–318}}<ref name="naomi-grigg-2014"/>{{rp|22–24}}<ref name="bones-bearings-skate-rated-system"/><ref>{{cite web
|url=https://www.devaskation.com/what-are-swiss-bearings/
|title=What are Swiss Bearings?
|website=Devaskation
|url-status=live
|archive-url=https://web.archive.org/web/20250418171329/https://www.devaskation.com/what-are-swiss-bearings/
|archive-date=2025-04-18
|access-date=2025-05-17
}}</ref>

[[File:Inline bearings-Max ILQ-like Abec 3-Disassembled-IMG 7556-FRD.jpg|thumb|right|300px|Bearing styled after TWINCAM ILQ-7]]

Similarly, TWINCAM bearings were developed in the early 1990s specifically for inline skating and were promoted with the slogan “Beyond ABEC”. In 1991, the company launched serviceable bearings featuring removable shields held in place with a C-clip, allowing for easier maintenance. The following year, it introduced TK CLASSIC Racing Gel, a water-repellent lubricant formulated for inline skating. In 2002, '''TWINCAM''' debuted the '''ILQ-9''', a 6-ball bearing - an alternative to the standard 7-ball 608 bearings widely used at the time. The company later expanded the line with models such as ILQ-9 Pro with rubber shields, ILQ-7 with 7 balls (commonly found in OEM skates), ILQ-X mr2 with a 29% weight reduction, and ILQ-Midget with 11 balls. TWINCAM trademarked '''ILQ''' (InLine Qualified) as a proprietary quality rating system, positioning it as a specialized alternative to the ABEC scale. Various ILQ models are rebranded and distributed by major inline skate companies, including FR Skates, K2, Rollerblade, and Powerslide/Wicked.<ref name="twincam-ilq-asia-access-history">{{cite web
|url=http://www.twincambearing.com/
|title=TWINCAM home page
|website=TWINCAM Bearing
|url-status=dead
|archive-url=https://web.archive.org/web/20130305191532/http://www.twincambearing.com/
|archive-date=2013-03-05
|access-date=2025-05-16
}}</ref><ref name="loco-skates-on-twincam-ilq-bearings">{{cite web
|url=https://www.locoskates.com/blogs/help-articles/what-does-twincam-and-ilq-bearings-mean
|title=What are Twincam and ILQ Bearings?
|date=2025-02-13
|website=Loco Skates
|url-status=live
|archive-url=https://web.archive.org/web/20250512020518/https://www.locoskates.com/blogs/help-articles/what-does-twincam-and-ilq-bearings-mean
|archive-date=2025-05-12
|access-date=2025-05-16
}}</ref><ref name="skatepro-all-aspects-of-speed-skates"/>