Editing Inline skates (section)

=== Wheel hubs ===

{{multiple image
 | direction = horizontal
 | total_width = 300
 | image1 = Lloyd Gerhardt Keleny-US5897170A-1999-Inline skate wheel-Patent Drawing-FIG 2.png
 | image2 = Revision Flex Hockey Wheels-80mm-Firm-76A-IMG 6339-backlit-bg-FRD.png
 | footer = Clear polyurethane tire molded over interlock vanes of a plastic hub
}}

{{multiple image
 | direction = horizontal
 | total_width = 300
 | image1 = Cross sectional view-Labeda Polyurethane inline skate wheel-cut in half-80mm 85A-Composition-IMG 6393-IMG 6359-IMG 6366-bg-FRD.png
 | image2 = Ceasura wheel 2-3-rorated-bg removed.png
 | footer = Tire chemically-bonded to the interlock rim (left) vs. mechanical interlock (right)
}}

The outer rim of the hub, known as the '''interlock''', is buried within the polyurethane tire. Unless the tire is made from clear urethane, this rim remains hidden from view. Its size, shape, and design vary depending on the wheel’s outer diameter and the demands of different skating disciplines. Beyond mechanically securing the tire to the hub, the interlock rim also enhances the wheel’s overall structural rigidity.{{efn-ua|name=brennan-olson-1987-patent-notes-on-wheel-structure|Brennan Olson's 1987 patent described wheels with polyurethane poured over a hub with an interlock rim (outer rigid ring 46), and showed drawings of the same.<ref name="brennan-olson-1987-patent-modern-inline-skates"/>}}{{efn-ua|name=kryptonic-rollerblade-wheel-collab-1980s}}<ref name="us-patent-5312844-sw-plastics-process-pu-molded-over-interlock">{{Cite patent
|country=US
|number=5312844
|fdate=1993-05-14
|pubdate=1994-05-17
|gdate=1994-05-17
|title=Method of producing polyurethane injection molded in-line skate wheels
|inventor1-first=Stanley
|inventor1-last=Gonsior
|assign1=S&W Plastics Inc
}}</ref><ref name="powerslide-download-guides-wheels">{{cite web
|url=https://powerslide.com/cdn/shop/files/PS_WHEELS_INFOGRAPHICS_final.pdf
|title=Powerslide Wheels Guide
|website=Powerslide
|url-status=live
|archive-url=https://web.archive.org/web/20240531222450/https://powerslide.com/cdn/shop/files/PS_WHEELS_INFOGRAPHICS_final.pdf
|archive-date=2024-05-31
|access-date=2025-03-22
}}</ref> Some manufacturers apply a bonding agent to the hub before pouring the polyurethane, creating a chemical bond that reduces reliance on mechanical interlocking. Others use polyurethane-blended plastic hubs, such as "Estaloc," developed by Robert J. Labeda of Labeda Wheels in collaboration with B.F. Goodrich, which chemically bonds with the polyurethane tire during the molding process.{{efn-ua|name=ricardo-lino-with-tony-gabriel-tour-wheel-factory-notes}}<ref name="hockey-office-brand-faqs-labeda">{{cite web
|url=https://www.hockeyoffice.com/information-for-brands-and-products-ice-hockey/faq-manufaktur/
|title=Hockey brands faq - Labeda
|website=Hockey Office
|url-status=live
|archive-url=https://web.archive.org/web/20250329162257/https://www.hockeyoffice.com/information-for-brands-and-products-ice-hockey/faq-manufaktur/
|archive-date=2025-03-29
|access-date=2025-03-29
}}</ref>

The visible portion of the hub varies in size depending on the wheel’s overall dimensions and the requirements of specific skating disciplines. In some small wheels used for aggressive skating, the visible hub may appear as a thin ring between the bearings and the tire, just large enough to serve as a bearing housing. In contrast, larger racing wheels from the 1990s, typically around 82mm in diameter, often featured hubs occupying nearly 50% of the wheel’s diameter. By the 2020s, even larger wheels from 110mm to 125mm feature hubs that take up most of the wheel’s diameter.<ref name="joyner-inline-hockey-1995"/>{{rp|19–24}}<ref name="powell-svensson-inline-skating"/>{{rp|26–27}}<ref name="powerslide-download-guides-wheels"/><ref name="skatepro-complete-guide-to-inline-wheels">{{cite web
|url=https://www.skatepro.com/en-us/a15.htm
|title=Wheels for Inline Skates - A Complete Guide
|website=SkatePro
|url-status=live
|archive-url=https://web.archive.org/web/20250131235431/https://www.skatepro.com/en-us/a15.htm
|archive-date=2025-01-31
|access-date=2025-03-27
}}</ref>

{{multiple image
 | direction = horizontal
 | image1 = Revision Flex Hockey Wheels-80mm-Firm-76A-IMG 6326-top view-bg-FRD.png
 | image2 = Powerslide Spinner 90mm 88A inline skate wheels with Wicked ABEC 9 bearings-IMG 5926-bg-FRD.png
 | image3 = Powerslide Trident 100mm X-Grip Dual Density inline skate wheels with Wicked ABEC 9 bearings-IMG 4817-bg-FRD.png
 | image4 = Undercover Team Blank 110mm 86A inline skate wheel with Bones REDS bearings-IMG 4971-bg-FRD.png
 | width1 = 104
 | width2 = 117
 | width3 = 130
 | width4 = 143
 | footer = Spoked hubs in 80mm, 90mm, 100mm & 110mm wheels
}}

{{multiple image
 | direction = horizontal
 | image1 = Rollerblade 303 70mm 85A hubless inline skate wheels by Kryptonics ca 1980s-608ZZ TMK bearings-IMG 6726-bg-FRD.png
 | image2 = Razors Shift Pro Jeph Howard 2 60mm 90A aggressive wheel w bearings-IMG 6607-bg-FRD.png
 | image3 = Roces Impala 2023 Lightspeed Fairy Floss 70mm 84A inline skate wheel w bearings-IMG 6671-bg-FRD.png
 | image4 = Labeda Gripper Asphalt 80mm 85A inline skate wheel-IMG 6707-bg-FRD.png
 | width1 = 91
 | width2 = 78
 | width3 = 91
 | width4 = 104
 | footer = Hubless (no core), closed core, open 70mm & 80mm
}}

As wheel sizes increase, so too do their visible hubs. A solid polyurethane wheel of substantial size would be prohibitively heavy and excessively flexible, making it impractical for inline skating. To address this, large inline wheels adapted design principles from polyurethane stroller wheels, incorporating lightweight yet rigid '''spoked hubs''' with an interlock rim to secure the polyurethane tire. These spoked hubs, also known as '''open cores''', feature an outer rim connected to the bearing housing by distinct spokes. In contrast, a '''full hub''', also referred to as a '''closed core''', consists of a solid disc with no clear separation between the outer rim and the bearing housing. Between these two designs is the '''semi-open core''', which features a solid disc but with small hollows drilled between the outer rim and bearing housing to reduce weight.<ref>{{Cite patent
|country=US
|number=4447093
|fdate=1982-08-09
|pubdate=1984-05-08
|gdate=1984-05-08
|title=Wheel
|inventor1-first=Joel C.
|inventor1-last=Cunard
|inventor2-first=William H.
|inventor2-last=Ziegler
|assign1=Brown Group Recreational Products Inc
}}</ref><ref name="powerslide-download-guides-wheels"/><ref name="powell-svensson-inline-skating"/>{{rp|26–27}}<ref name="le-roller-en-ligne-on-inline-wheels"/>

Spoked cores are generally lighter than full cores but may offer reduced rigidity and structural integrity. As a result, aggressive skaters typically favor small wheels with robust full cores to ensure durability against the high impact of jumps and landings. Conversely, speed and marathon skaters prefer large wheels with spoked hubs, as the open core design allows air to circulate around the hub, helping '''dissipate heat''' generated by the bearings during prolonged high-speed use. Without adequate heat dissipation, the polyurethane tire may soften, increasing deformation during rolling and potentially leading to separation from the hub.<ref name="le-roller-en-ligne-on-inline-wheels"/><ref name="le-roller-en-ligne-on-physics-of-inline-skate-wheel"/><ref name="brennan-olson-1987-patent-modern-inline-skates"/><ref name="inlineskates-buying-guide-inline-skate-wheels">{{cite web
|url=https://www.inlineskates.com/Buying-Guide-for-Inline-Skate-Wheels/buying-guide-5-3-2013,default,pg.html
|title=Buying Guide for Inline Skate Wheels
|first1=Steve
|last1=Kopitz
|website=Inline Skates
|url-status=dead
|archive-url=https://web.archive.org/web/20210805202216/https://www.inlineskates.com/Buying-Guide-for-Inline-Skate-Wheels/buying-guide-5-3-2013,default,pg.html
|archive-date=2021-08-05
|access-date=2025-04-04
}}</ref>