Wire wheel

For the tool, see wire brush.

Wire wheels on a penny-farthing

Wire wheels on the first Harley-Davidson motorcycle

Wire wheels on a Blériot XI

Wire wheels on a 1929 Alfa Romeo 6C 1750 Spyder Supersport

File:Vauxhall wheel - Flickr - exfordy.jpg

Wire wheels on a 1957 MGA

Wire wheels, wire-spoked wheels, tension-spoked wheels, or "suspension" wheels are wheels whose rims connect to their hubs by wire spokes. Although these wires are generally stiffer than a typical wire rope, they function mechanically the same as tensioned flexible wires, keeping the rim true while supporting applied loads. The term suspension wheel should not be confused with vehicle suspension.

Wire wheels are used on most bicycles and are still used on many motorcycles. They were invented by aeronautical engineer George Cayley in 1808. Although Cayley first proposed wire wheels, he did not apply for a patent. The first patent for wire wheels was issued to Theodore Jones of London, England on October 11, 1826. Eugène Meyer of Paris, France was the first person to receive, in 1869, a patent for wire wheels on bicycles.

Bicycle wheels were not strong enough for cars until the development of tangentially spoked wheels. They rapidly became well established in the bicycle and motor tricycle world but were not common on cars until around 1907. This was encouraged by the Rudge-Whitworth patented detachable and interchangeable wheels designed by John Pugh. These wheels owed their resistance to braking and accelerative stresses to their two inner rows of tangential spokes. An outer row of radial spokes gave lateral strength against cornering strains. These wheels were deeply dished so that steering pivot pins might lie as near as possible to the center-line of the tires. Their second feature was that they were easily detachable being mounted on splined false hubs. A process of assembling wire wheels is described as wheelbuilding.

On automobiles

After their artillery wheels proved inadequate US manufacturers paid John Pugh of Rudge-Whitworth royalties to manufacture wire wheels using his patents. This continued until the development of pressed steel wheels by Joseph Sankey which replaced wire wheels wherever the premium price of wire wheels was not justified by their weight saving.

• A sample of US-made cars first riding on wire wheels
• 1929 Cadillac .jpg

  Cadillac

• 

  Chrysler

• 

  Ford

• 

  Lincoln

• 

  Packard

• 

  Rolls-Royce Phantom III 1937 high-quality centre-lock (wire) wheels streamlined by nave plates

Sports cars

See also: Rudge-Whitworth and Borrani

Before 1960, sports/racing cars usually had Rudge-Whitworth wire wheels center-locking equipped with splined hubs and a quick-release "knockoff" (central wing nut) locking cap that could be unscrewed by striking a wing of the nut with a special alloy mallet or "knockoff hammer". Some jurisdictions, including West Germany, prohibited eared hubcaps. Some manufacturers (e.g. Maserati) preferred to hold the wheel on the splined hub by capping with a single conventional unwinged nut requiring a special large spanner.

In the 1960s even lighter cast alloy wheels became usual—at first with splined hubs and knock-off caps—and now predominate. New versions of wire wheels are still made but often with standard hub bolt patterns covered by a center cap to fit without adapters.

• 

  Ferrari knock-on wire-spoked wheel
  by Italian manufacturer Ruote Borrani, in Milan

• 

  Ferrari knock-on cast wheel
  by Italian manufacturer Ruote Borrani, in Milan

On motorcycles

Main article: Motorcycle wheel

At one time, motorcycles used wire wheels built up from separate components, but, except for dirtbikes, they are now used mainly for their retro appearance.

• 

  Wire wheels on a 1906 Curtiss V-8 motorcycle

• 

  Wire wheels on a French San Sou Pap motorcycle

• 

  Wire wheels on a modern motocross-style motorcycle

• 

  Wire wheels on a modern enduro-style motorcycle

• 

  Wire wheels on a modern cruiser-style motorcycle

On bicycles

Main article: Bicycle wheel

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. This development marked a major improvement 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 Stanley 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.

In the 1980s, 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

The reaction to a radial load of a well-tensioned wire spoked wheel, such as by a rider sitting on a bicycle, is that the wheel flattens slightly near the ground contact area. The rest of the wheel remains approximately circular. The tension of all the spokes do not increase significantly. Instead, only the spokes directly under the hub decrease their tension. The issue of how best to describe this situation is debated. Some authors conclude from this 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.

Despite being composed of thin and relatively flexible spokes, wire wheels are radially stiff and provide very little suspension compliance compared to even high-pressure bicycle tires.

Gallery

• 

  Bicycle wheels with a radial spoke pattern (left) and three cross (right)

• 

  Early Harley-Davidson with wire wheels

External links

• Astounding.org.uk, an analysis of the deflection of wire wheels.
• Duke.edu, an analysis of the deflection of wire wheels (PDF format).