Rim (wheel)

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Cutaway diagram of a rim and tire from an ATV ATV Rim Lip Parts.jpg
Cutaway diagram of a rim and tire from an ATV
Cross section of a bicycle rim Felge-querschnitt.jpg
Cross section of a bicycle rim
A wooden bicycle rim with tubular tire 16-11-18-Holzfelge mit Schlauchreifen-RR2 7364.jpg
A wooden bicycle rim with tubular tire

The rim is the "outer edge of a wheel, holding the tire". [1] It makes up the outer circular design of the wheel on which the inside edge of the tire is mounted on vehicles such as automobiles. [2] For example, on a bicycle wheel the rim is a large hoop attached to the outer ends of the spokes of the wheel that holds the tire and tube. [3] In cross-section, the rim is deep in the center and shallow at the outer edges, thus forming a "U" shape that supports the bead of the tire casing. [4]

Contents

In the 1st millennium BC, an iron rim was introduced around the wooden wheels of chariots to improve longevity on rough surfaces. [5]

Characteristics

Scratched rim on a one-piece alloy wheel. The black residue remains from where the tire was seated on the "safety profile" rim. Scratched rim on one-piece wheel.jpg
Scratched rim on a one-piece alloy wheel. The black residue remains from where the tire was seated on the "safety profile" rim.
Thomas B. Jeffery's 1882 clincher rim patent Tbj clincher tire.jpg
Thomas B. Jeffery's 1882 clincher rim patent
Design
The first pneumatic tires for bicycles were simple tubes in shape secured to the wooden outer concave surfaced circumference of the wheel by glue and air pressure pressing them against it. [6] The surface for receiving the tube was not very secure thus causing the tires to sometimes come off the rims. [6] Bicycle manufacturer and inventor Thomas B. Jeffery developed an improved tire that had a wire embedded in the rubber of the tire; that wire could be tightened onto the rim. [7] His 1882 patent became the ancestor of all clincher tires, the design found on modern bikes and cars. [7] Modern clincher tires have wires embedded on both beads of the tire so the wires fit inside the edges of the rim to hold the tire in place when it is fully inflated. [7]
Diameter (effective)
A distance between the bead seats (for the tire), as measured in the plane of the rim and through the axis of the hub which is or will be attached, or which is integral with the rim.
Width (effective)
A separation distance between opposed rim flanges. The flange-to-flange width of a rim should be a minimum of three-quarters of the tire section width. And the maximum rim width should be equal to the width of the tire tread.
Type
Depends on the type of vehicle and tire. There are various rim profiles, as well as several rim components.
Modern passenger vehicles and tubeless tires typically use one-piece rims with a "safety" rim profile. The safety feature helps keep the tire bead held to the rim under adverse conditions by having a pair of safety humps extending inwardly of the rim toward the other tire bead seat from an outer contoured surface of the rim. [8]
Heavy vehicles and some trucks may have a removable multi-piece rim assembly consisting of a base that mounts to the wheel and axle. They then have either a side ring or a side and lock ring combination. These parts are removable from one side for tire mounting, while the opposite side attached to the base has a fixed flange.
Low tire pressure applications such as off-roading and drag racing use a beadlock that clamps or physically attaches the bead of the tire to the rim of the wheel. This reduces the chance of the tire separating from the rim, causing a sudden deflation. [9]
Material
Various metals can be used for the rim. Commonly seen are alloy (magnesium and aluminum), mag (magnesium), aluminum, and chrome. Teflon coatings are sometimes also applied for an extra layer of protection.
Vehicle performance
Because the rim is where the tire resides on the wheel and the rim supports the tire shape, the dimensions of the rims are a factor in the handling characteristics of a vehicle. For example:
Overly wide rims in relation to the tire width for a particular car may result in more vibration and a less comfortable ride because the sidewalls of the tire have an insufficient curvature to flex properly over rough driving surfaces. Oversized rims may cause the tire to rub on the body or suspension components while turning.
Overly narrow rims in relation to the tire width may cause poor handling, as the tire may distort sideways under fast cornering. On motorcycles, a narrow rim will alter the tire profile, concentrating tire wear in a very small area during cornering, with a smaller contact patch during braking. [10]
On bicycles, the optimum tire width is about 1.8 times the rim's internal width. [11] An example is a 35 mm tire on a rim with an ETRTO 17 mm internal width, or one-and-a-half times the rim's external width. Considerable variation outside this range is safe, but very wide tires on a narrow rim can overstress the rim and damage the tire sidewalls, whereas very narrow tires on a wide rim give a hard ride and can result in a high-pressure tire blowing off. [11] However, wider wheels and wider tires are increasingly popular, making prrievious guidelines obsolete because manufacturers are focused on providing a more comfortable and faster riding experience. [12]

Production

Damage to the rim can cause vibration and cause a tubeless tire to fail to hold pressure BentRim.jpg
Damage to the rim can cause vibration and cause a tubeless tire to fail to hold pressure

A standard automotive steel wheel rim is made from rectangular sheet metal. The metal plate is bent to produce a cylindrical sleeve, and then the two free edges of the sleeve are welded together. At least one cylindrical flow spinning operation is carried out to obtain the desired thickness profile of the sleeve—and the desired angle of inclination relative to the axial direction in the zone for the outer seat. The sleeve is then shaped to obtain the rims on each side with a radially inner cylindrical wall in the zone of the outer seat and with a radially outer frustoconical wall inclined at an angle corresponding to the standard inclination of the rim seats. The rim is then calibrated. [13]

To support the cylindrical rim structure, a disc is made by stamping a metal plate. It has to have appropriate holes for the center hub and lug nuts. The radial outer surface of the wheel disk has a cylindrical geometry to fit inside the rim. The rim and wheel disk are assembled by fitting together under the outer seat of the rim and then being welded together. [13] The disk is welded in place such that the center of the wheel is equal to the center of the hub. The distance between the centerline of the rim and the mounting plane of the wheel is called the "offset" and can be positive, negative, or zero. [14]

One-piece rim and wheel assemblies (see image) may be obtained by casting or forging.

Meaning

Used broadly, or used figuratively, the word rim can mean the outer edge of any circular object. [15] [16]

On a bicycle wheel, the rim is clearly just one component of the assembly, and it can be purchased separately and replaced if damaged or if the sidewalls have been eroded by rim brakes. [17]

In discussions of automobiles, however, the terms wheel and rim are often incorrectly used synonymously, as in decorative wheels being called rims. One engineering text says, "alloy wheels [are] often incorrectly called aluminum rims". [18]

Some authors are careful to use rim literally for only the outer portion of a wheel, where the tire mounts, [19] just as the rim of a coffee cup or a meteor crater does not refer to the entire object. Others use rim to mean the entire metal part to which the tire mounts, [20] because the rim and the wheel are often cast or stamped from a single piece of metal instead of being distinct as with wire wheels. At the same time, "wheel" may refer to the entire rotating assembly, including the tire. [21] [22]

Railroad usage

In railroad usage, the conical running surface of the wheels may be called a rim, a wheel tread, or a tire.

Historical development

Early wheels of motor vehicles started as bicycle wheels, with the rims attached to the central axle by spokes. As vehicles became heavier, wood-spoked wagon wheels with steel rims were used. Later, solid rubber tires were mounted on the rims of those wooden wheels. Some wooden automobile wheels had a demountable steel rim that was bolted onto the outer circumference of the wooden wheel. Wheels that were completely made of metal (single or multiple pieces) gradually became widespread around the 1930s. [23]

See also

Related Research Articles

<span class="mw-page-title-main">Tire</span> Ring-shaped covering that fits around a wheels rim

A tire or tyre is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface.

<span class="mw-page-title-main">Mountain bike</span> Type of bicycle

A mountain bike (MTB) or mountain bicycle is a bicycle designed for off-road cycling. Mountain bikes share some similarities with other bicycles, but incorporate features designed to enhance durability and performance in rough terrain, which often makes them heavier, more complex and less efficient on smooth surfaces. These typically include a suspension fork, large knobby tires, more durable wheels, more powerful brakes, straight, extra wide handlebars to improve balance and comfort over rough terrain, and wide-ratio gearing optimised for topography, application and a frame with a suspension mechanism for the rear wheel. Rear suspension is ubiquitous in heavier-duty bikes and now common even in lighter bikes. Dropper seat posts can be installed to allow the rider to quickly adjust the seat height.

<span class="mw-page-title-main">Spoke</span> Part of a wheel extending radially from the hub to the rim

A spoke is one of some number of rods radiating from the center of a wheel, connecting the hub with the round traction surface.

<span class="mw-page-title-main">Bicycle brake</span> Braking device for bicycles

A bicycle brake reduces the speed of a bicycle or prevents the wheels from moving. The two main types are: rim brakes and disc brakes. Drum brakes are less common on bicycles.

<span class="mw-page-title-main">Bicycle wheel</span> Wheel designed for a bicycle

A bicycle wheel is a wheel, most commonly a wire wheel, designed for a bicycle. A pair is often called a wheelset, especially in the context of ready built "off the shelf" performance-oriented wheels.

<span class="mw-page-title-main">Racing bicycle</span> Bicycle designed for competitive road cycling

A racing bicycle, also known as a road bike is a bicycle designed for competitive road cycling, a sport governed by and according to the rules of the Union Cycliste Internationale (UCI).

<span class="mw-page-title-main">Cyclo-cross bicycle</span> Bicycle designed for cyclo-cross racing

A cyclo-cross bike or cyclo-cross bicycle is a bicycle specifically designed for the rigors of a cyclo-cross race. Cyclo-cross bicycles roughly resemble the racing bicycles used in road racing. The major differences between the two are the frame geometry, and the wider clearances that cyclo-cross bikes have for their larger tires and mud and other debris that they accumulate.

<span class="mw-page-title-main">Wheel sizing</span> Measuring a wheel rim diameter to find the wheels size

The wheel size for a motor vehicle or similar wheel has a number of parameters.

<span class="mw-page-title-main">ISO 5775</span> International standard for labeling the size of bicycle tires and rims

ISO 5775 is an international standard for labeling the size of bicycle tires and rims. The system used was originally developed by the European Tyre and Rim Technical Organisation (ETRTO). It is designed to make tire sizing consistent and clear. It replaces overlapping informal systems that ambiguously distinguished between sizes. For example, at least 6 different "26 inch" sizes exist, and "27 inch" wheels have a larger diameter than American "28 inch" wheels. The Japanese Industrial Standards Committee also cooperates with ISO 5775. The corresponding Japanese standards are JIS D 9112 for tires and JIS D 9421 for rims.

<span class="mw-page-title-main">Snow chains</span> Devices fitted to the tires of vehicles to improve traction on snow and ice

Snow chains, or tire chains, are devices fitted to the tires of vehicles to provide increased traction when driving through snow and ice.

A beadlock or bead lock is a mechanical device that secures the bead of a tire to the wheel of a vehicle. Tires and wheels are designed so that when the tire is inflated, the tire pressure pushes the bead of the tire against the inside of the wheel rim so that the tire stays on the wheel and the two rotate together. In situations where tire pressure is insufficient to hold the bead of the tire in place, a beadlock is needed.

<span class="mw-page-title-main">Thomas B. Jeffery</span>

Thomas Buckland Jeffery was a British emigrant to the United States who co-founded the Gormully & Jeffery company which made the Rambler bicycle. He invented the "clincher" rim which was widely used to fit tires to bicycles and early automobiles, and in 1900 established the Thomas B. Jeffery Company to make automobiles, again using Rambler branding.

<span class="mw-page-title-main">Zipp</span> American cycling components company

Zipp is an American company that is best known for designing, manufacturing, and marketing carbon-composite bicycle wheels for road cycling, triathlons, track racing, and mountain biking. The company's product range also includes handlebars, stems, seat posts, tires, inner tubes, handlebar tape, and bags.

Plus sizing is the practice of replacing an automotive wheel with one of a larger diameter fitted with a new tire of lower aspect ratio so that the new tire has close to the same diameter and circumference as the original tire to minimize any changes in speedometer accuracy, torque and traction control, while reducing sidewall flex and (generally) increasing cornering ability.

A tubeless tire is a pneumatic tire that does not require a separate inner tube.

<span class="mw-page-title-main">Bead breaker</span> Automotive Tool

A bead breaker is a tool used for separating tires from rims. The innermost diameter of the tire that interfaces with the rim of a wheel is called the tire bead. The bead is a thicker section of rubber, and is reinforced with braided steel cables, called the bead bundle. The surface of the bead creates a seal between the tire and rim on radial and bias-ply tires.

<span class="mw-page-title-main">Bicycle tire</span> Tire that fits on the wheel of a bicycle

A bicycle tire is a tire that fits on the wheel of a bicycle or similar vehicle. These tires may also be used on tricycles, wheelchairs, and handcycles, frequently for racing. Bicycle tires provide an important source of suspension, generate the lateral forces necessary for balancing and turning, and generate the longitudinal forces necessary for propulsion and braking. Although the use of a pneumatic tire greatly reduces rolling resistance compared to the use of a rigid wheel or solid tire, the tires are still typically the second largest source, after wind resistance, of power consumption on a level road. The modern detachable pneumatic bicycle tire contributed to the popularity and eventual dominance of the safety bicycle.

<span class="mw-page-title-main">Motorcycle tyre</span> Tyres of a motorcycle

A motorcycle tyre is the outer part of motorcycle wheel, attached to the rim, providing traction, resisting wear, absorbing surface irregularities, and allowing the motorcycle to turn via countersteering. The two tyres' contact patches are the motorcycle's connection to the ground, and so are fundamental to the motorcycle's suspension behaviour, and critically affect safety, braking, fuel economy, noise, and rider comfort.

A railway or railroad is a track where the vehicle travels over two parallel steel bars, called rails. The rails support and guide the wheels of the vehicles, which are traditionally either trains or trams. Modern light rail is a relatively new innovation which combines aspects of those two modes of transport. However fundamental differences in the track and wheel design are important, especially where trams or light railways and trains have to share a section of track, as sometimes happens in congested areas.

References

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  2. "Definition of rim". Collins English Dictionary. 2023. Retrieved 19 April 2023. a. the outer, circular part of a wheel b. the metal flange surrounding the wheel of an automotive vehicle, on which the tire is mounted
  3. "Definition of rim". WordReference Random House Learner's Dictionary of American English. 2023. Retrieved 19 April 2023. 1. the outer edge or border of something:a chip on the rim of the glass. 2. the outer circle of a wheel, attached to the hub by spokes.
  4. Forester, John (1993). Effective Cycling. MIT Press. ISBN   9780262560702 . Retrieved 19 April 2023 via Google Books.
  5. Timelines of Science. Penguin. 2013. p. 20. ISBN   9781465421234 . Retrieved 19 April 2023 via Google Books.
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  7. 1 2 3 Rubenson, Paul (9 March 2005). "Thomas B. Jeffery, Clincher Tires". Patent Pending Blog - Patents and the History of Technology. Retrieved 19 April 2023.
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  11. 1 2 Arthur, David (25 October 2021). "How to choose the best width road tyres for your riding". road.cc. Retrieved 19 April 2023.
  12. "How Wide Wheels and Wide Tires Can Make You Faster". In The Know Cycling. 10 June 2022. Retrieved 19 April 2023.
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  14. Kershaw, John; VanGelder, Kirk (2017). Automotive Steering and Suspension. Jones & Bartlett Learning. p. 144. ISBN   9781284147490 . Retrieved 13 July 2018.
  15.  "rim, n.1.", OED Online, Oxford University Press, March 2016
      "rim. (n.d.)", Dictionary.com Unabridged, retrieved May 23, 2016
  16. "Wheel Tech: Wheel Construction". tirerack.com. Retrieved 26 June 2022. While many people refer to wheels as "rims," this is technically incorrect.
  17. Wikstrom, Matt (24 November 2016). "When to replace your road bike wheels". CyclingTips. Retrieved 19 April 2023.
  18. Reimpell, Jörnsen; Stoll, Helmut; Betzler, Jürgen W. (2001). The Automotive Chassis: Engineering Principles. Translated by AEGT Limited (German to English). Butterworth Heinemann. p. 115. ISBN   9780750650540 . Retrieved 19 April 2023 via Google Books.
  19. Walker, Rob (2007-06-17). "Donk my ride". The New York Times. Retrieved 19 April 2023. The second trend is rim inflation, the ... popularity of increasingly large wheels ...
  20. "rim, a. The peripheral portion or outer ring of a wheel". Oxford University Press. Retrieved 19 April 2023. 2009 Miami Herald (Nexis) 19 Feb. 8 The rims and tires were taken off a 2006 Ford...and the car was left mounted on bricks.
  21. Bennett, Sean (2010). Heavy Duty Truck Systems. Cengage Learning. pp. 855–856. ISBN   9781435483828 . Retrieved 13 July 2018. The term wheel may be used in several ways...
  22. Duke, Tom (19 November 2012). "Tire Wheel Balancing Steps". Tire Review Magazine. Retrieved 19 April 2023.
  23. Darmsted, Clint. "The Evolution of the Ford Wheel" (PDF). Northwest Vintage Speedsters Club. Retrieved 15 March 2021.