The rims of
wire wheels (or "wire spoked wheels") are connected to their hubs by wire
spokeA spoke is one of some number of rods radiating from the center of a wheel , connecting the hub with the round traction surface....
s. Although these
wireA wire is a single, usually cylindrical, string of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various wire gauges...
s are generally stiffer than a typical
wire ropethumb|Steel wire rope Wire rope consists of several strands laid together like a helix. Each strand is likewise made of metal wires laid together like a helix...
, they function mechanically the same as
tensionTension may refer to:*Tension , a force related to the stretching of an object *Tension , the perceived need for relaxation or release created by a listener's expectations...
ed flexible wires, keeping the rim true while supporting applied loads.
Wire wheels are used on most
bicycleA bicycle, also known as a bike, push bike or cycle, is a pedal-driven, human-powered vehicle with two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist or a bicyclist....
s and motorcycles. They were invented by aeronautical engineer
George CayleySir George Cayley, 6th Baronet was a prolific English engineer, one of the most important people in the history of aeronautics. Many consider him the first true scientific aerial investigator and first person to understand the underlying principles and forces of flight...
and first used in bicycles by
James StarleyJames Starley was an English inventor and "Father of the Bicycle Industry." He was born in 1831 at Albourne. James Starley ran away from home and later settled in Coventry where he became one of the most innovative and successful builders of bicycles and tricycles...
. A process of assembling wire wheels is described as
wheelbuildingWheelbuilding is the art and science of assembling a wheel from its component rim, spokes, nipples and hub.-Goals:...
.
On automobiles
Before 1960, sports/racing cars often had wire wheels equipped with "knockoff" (central wing nut) hubs that could be unscrewed by striking a wing of the nut with a mallet or "knockoff hammer", but in the 1960s cast light-alloy or "Mag(nesium)" wheels became common and now predominate.
On motorcycles
On bicycles
The first commercially successful use of wired wheels was on bicycles. They were introduced early on in the development of the bicycle, following soon after the adoption of solid rubber tires. It marking a major improvement in bicycles, over the older wooden wheels, both in terms of weight and comfort (the increased elasticity of the wheel helping to absorb road vibrations).
In England, the engineer
William StanleyWilliam Ford Robinson Stanley was a British inventor, engineer and philanthropist. He founded Stanley Trades School, renamed as Stanley Technical School ....
developed the
steel-wired spider wheel in 1849, an improvement over the cumbersome wooden spoked wheels then fitted to the tricycles that his employer was making.
Bicycle manufacturers build millions of wheels annually, using the common crossed-spoke patterns whose crossings of adjacent spokes are governed by the number of spokes in the wheel. Wheelbuilders of racing teams and in good bicycle shops build wheels to other patterns such as two-cross, one-cross, or no-cross (usually called radial). Many of these patterns have been used for more than 100 years, it is claimed that crossed patterns have more strength and stability while irregular patterns are art forms and have little structural merit (Brandt, 1993).
In the 1980's, cast wheels with 5 or 6 rigid spokes began to appear in the Olympic Games and professional racing: these have advantages in specialized applications, such as time trials, but wire-spoked wheels are used for most purposes.
Reaction to load
When a radial load is applied at the hub to a well tensioned wheel, such as by a rider sitting on a bicycle, it causes the wheel to flatten slightly near the ground contact area. The rest of the wheel remains approximately circular.
The tension of all the spokes does not increase significantly. Instead, only the spokes directly under the hub have decreased tension.
Some authors conclude that the hub "stands" on those spokes immediately below it that experience a reduction in tension. Other authors conclude that the hub "hangs" from those spokes above it that have higher tension than the ones below it.
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