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]
In the 1st millennium BC, an iron rim was introduced around the wooden wheels of chariots to improve longevity on rough surfaces. [5]
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.
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]
In railroad usage, the conical running surface of the wheels may be called a rim, a wheel tread, or a tire.
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]
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.
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.
A spoke is one of some number of rods radiating from the center of a wheel, connecting the hub with the round traction surface.
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.
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.
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).
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.
The wheel size for a motor vehicle or similar wheel has a number of parameters.
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.
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.
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.
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.
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.
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.
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.
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
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.
While many people refer to wheels as "rims," this is technically incorrect.
The second trend is rim inflation, the ... popularity of increasingly large wheels ...
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.
The term wheel may be used in several ways...