Editing Tire (section)

==Construction types==
[[File:Tire plies.png|thumb|A cross-section of a tire showing ply orientations]]

Tire construction spans [[Pneumatics|pneumatic]] tires used on cars, trucks, and aircraft, but also includes non-automotive applications with slow-moving, light-duty, or railroad applications, which may have non-pneumatic tires.

===Automotive===
Following the 1968 ''[[Consumer Reports]]'' announcement of the superiority of the radial design, [[radial tire]]s began an inexorable climb in market share, reaching 100% of the North American market in the 1980s.<ref name="A Tale of Two Tires" /> Radial tire technology is now the standard design for essentially all automotive tires, but other methods have been used.<ref name=":0A" />

Radial (or radial-ply) tire construction utilizes body ply cords extending straight across the tread from bead to bead—so that the cords are laid at approximately right angles to the centerline of the tread, and parallel to one another—as well as stabilizer belts directly beneath the tread. The plies are generally made of nylon, polyester, or steel, and the belts of steel, fiberglass, or [[Kevlar]].<ref>{{cite web |url=https://agtiretalk.com/tire-casing-construction-poly-vs-nylon-vs-steel/ |title=Tire Casing Construction: Poly Vs Nylon Vs Steel |last=Tuschner |first=James |date=30 August 2021 |website=AG Tire Talk |access-date=11 September 2024}}</ref><ref>{{cite web |url=https://tiregrades.com/tire-anatomy/what-is-a-radial-tire/ |title=What Is a Radial Tire? |last=Creech |first=Will |date=12 May 2023 |website=TireGrades |access-date=27 July 2024}}</ref> The tire's footprint, wider than a bias tire's, and flexible sidewalls provide a better grip in turns, and its circumferential belts stabilize it. The advantages of this construction over that of a bias tire are many, including longer tread life, better steering control, lower [[rolling resistance]], improved fuel economy, more uniform wear, higher heat resistance, fewer blowouts, and a steadier, more comfortable ride at speed. Disadvantages, besides a higher cost than that of bias tires, are a harder ride at low speeds and generally worse performance on rough terrain.<ref name="Holman">{{cite web |url=https://www.motortrend.com/how-to/129-1102-tire-construction-technology-bias-and-radial/ |title=Tire Construction Technology: Bias and Radial |last=Holman |first=Sean |date=1 February 2011 |website=MotorTrend |access-date=10 September 2024}}</ref><ref>{{cite web |url=https://mechanicinsider.com/radial-vs-bias-ply/ |title=Radial vs Bias Ply – Debate Ends Here! |last=Smith |first=David |website=Mechanic Insider |date=26 July 2020 |access-date=7 September 2024}}</ref><ref name=":0A" /> Radial tires are also seldom seen in diameters of greater than 42 inches, as such tires are difficult to make.<ref>{{cite web |url=https://www.intercotire.com/comparing_bias_ply_radial_tires_trent_mcgee |title=Comparing Bias Ply to Radial Tires |last=McGee |first=Trent |website=Interco Tire Corporation |access-date=27 July 2024}}</ref>

{{vanchor|Bias}} tire (bias-ply, or cross-ply) construction utilizes body ply cords that extend diagonally from bead to bead, usually at angles in the range of 30 to 40 degrees from the direction of travel.<ref>{{cite web |url=https://help.summitracing.com/knowledgebase/article/SR-04654/en-us |website=Summit Racing Equipment |access-date=10 September 2024}}</ref> Successive plies are laid at opposing angles, forming a crisscross pattern to which the tread is applied. Such a design is resistant to sidewall deformation and punctures (and to punctures’ expansion, or “torque splitting”) and therefore durable in severe use.<ref>{{cite web |url=https://whirlingwheelz.com/radial-vs-bias-ply-tires/ |title=Radial vs. Bias Ply Tires: Pros & Cons, Differences & Which to Choose |last=Niklas |date=9 March 2022 |website=Whirling Wheelz |access-date=14 September 2024}}</ref> Since the tread and sidewalls share their casing plies, the tire body flexes as a whole, providing the main advantage of this construction, better traction and smoother motion on uneven surfaces, with a greater tendency to conform to rocky ground and throw off mud and clay, especially because the rubber is usually of a softer compound than that used on radial tires. However, this conformity increases a bias tire's rolling resistance, and its stiffness allows less control, [[traction (engineering)|traction]], and comfort at higher speeds, while [[Shearing (physics)|shear]] between its overlapping plies causes friction that generates heat.<ref name="Holman"/><ref>{{cite web |url=https://www.mudthrowers.com/bias_vs_radial_tires |title=Bias vs Radial Construction |website=Mudthrowers |access-date=10 September 2024}}</ref><ref>{{cite web |url=https://help.summitracing.com/knowledgebase/article/SR-04655/en-us |website=Summit Racing Equipment |access-date=10 September 2024}}</ref><ref name=":0A" /> Still, bias tires benefit from simpler structure and so cost less than like-size radials, and they remain in use on heavy equipment and off-road vehicles, although the earthmoving market has shifted to radials.<ref name=":0A" /><ref>{{cite web |url=https://www.constructionequipment.com/trucking/article/10708762/how-off-road-radials-are-changing-earthmoving |title=How Off-Road Radials Are Changing Earthmoving |last=Stewart |first=Larry |date=28 September 2010 |website=Construction Equipment |access-date=10 September 2024}}</ref>

A belted bias tire starts with two or more bias plies to which stabilizer belts are bonded directly beneath the tread. This construction provides a smoother ride that is similar to the bias tire, while lessening rolling resistance because the belts increase tread stiffness. The design was introduced by Armstrong, while Goodyear made it popular with the "[[Goodyear Polyglas tire|Polyglas]]" trademark tire featuring a polyester carcass with belts of fiberglass.<ref name="pliesandangles">{{cite magazine|date=March 1972|title=Plies and angles - see how they run|url= https://books.google.com/books?id=LtUDAAAAMBAJ&q=Plies+and+angles+-+see+how+they+run+Until+1967+U.S.+tiremakers&pg=PA61 | magazine=Popular Mechanics |volume=136 |issue=3 |page=62 |access-date=13 March 2014}}</ref> The "belted" tire starts two main plies of polyester, rayon, or nylon annealed as in conventional tires, and then placed on top are circumferential belts at different angles that improve performance compared to non-belted bias tires. The belts may be fiberglass or steel.<ref name="pliesandangles" />

===Other===
[[File:2005 091112-28rim0051 compressed.JPG|thumb|[[Airless tire]]]]
[[Tubeless tire]]s are pneumatic tires that do not require a separate [[#On the wheel|inner tube]].

Semi-pneumatic tires have a hollow center, but they are not pressurized. They are lightweight, low-cost, puncture-proof, and provide cushioning.<ref>{{cite magazine|last=Jones|first=Thomas H. |year=1980 |title=Get things moving with casters, glides, and wheels |magazine=Popular Science |volume=216 |issue=5 |page=148 |issn=0161-7370}}</ref> These tires often come as a complete assembly with the wheel and even integral [[ball bearing]]s. They are used on [[lawn mower]]s, [[wheelchair]]s, and [[wheelbarrow]]s. They can also be rugged, typically used in industrial applications,<ref>{{cite web|url= http://www.thomasnet.com/products/semipneumatic-wheels-93980407-1.html |title=Thomas Net sources for industrial use 'Semi-Pneumatic Wheels'|publisher=Thomasnet.com |access-date=2010-10-23|archive-date=17 July 2011 |archive-url= https://web.archive.org/web/20110717051419/http://www.thomasnet.com/products/semipneumatic-wheels-93980407-1.html |url-status=dead}}</ref> and are designed to not pull off their [[Rim (wheel)|rim]] under use.

An [[airless tire]] is a non-pneumatic tire that is not supported by air pressure. They are most commonly used on small vehicles, such as golf carts, and on utility vehicles in situations where the risk of puncture is high, such as on construction equipment. Many tires used in industrial and commercial applications are non-pneumatic, and are manufactured from solid rubber and plastic compounds via molding operations. Solid tires include those used for lawnmowers, skateboards, golf carts, [[Kick scooter|scooters]], and many types of light industrial vehicles, carts, and trailers. One of the most common applications for solid tires is for material handling equipment (forklifts). Such tires are installed utilizing a hydraulic tire press.

[[Wheelwright|Wooden wheels]] for horse-drawn vehicles usually have a [[wrought iron]] tire. This construction was extended to wagons on horse-drawn tramways, rolling on [[Haytor Granite Tramway|granite setts]] or [[plateway|cast iron rails]].

The wheels of some railway engines and older types of rolling stock are fitted with [[railway tires]] to prevent the need to replace the entirety of a wheel. The tire, usually made of steel, surrounds the wheel and is primarily held in place by [[interference fit]].

Aircraft tires may operate at pressures that exceed {{convert|200|psi|kPa bar psi|lk=on|order=out}}.<ref>{{cite book|last=Fabre|first=C.|url= https://www.worldcat.org/oclc/636611702 |title=Bearing capacity of roads, railways and airfields: proceedings of the 8th International Conference on the Bearing Capacity of Roads and Airfields, Champaign, Illinois, USA, June 29-July 2, 2009|date=2009| publisher=CRC Press/Balkema|isbn=978-0-203-86528-6|editor-last=Tutumluer|editor-first=Erol |location=Leiden, Netherlands |pages=1405 |oclc=636611702 |editor-last2=Al-Qadi |editor-first2=Imad L.}}</ref> Some aircraft tires are inflated with [[nitrogen]] to "eliminate the possibility of a chemical reaction between atmospheric oxygen and volatile gases from the tire inner liner producing a tire explosion".<ref>{{cite web |url= http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/55850e6389efba3c8625695b006723a3!OpenDocument#_Section1 |title= FAA Airworthiness Directive |access-date= 2013-06-15 |archive-date= 2 February 2017 |archive-url= https://web.archive.org/web/20170202053815/http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/55850e6389efba3c8625695b006723a3!OpenDocument#_Section1 |url-status= dead }}</ref>