Would you drive a car with paper tires?
In the late nineteenth and early twentieth centuries, the pneumatic tire was all the rage. Described by its inventor Robert William Thomson as “a hollow belt composed of some air- and water-tight material such as sulphurized caoutchouc or gutta percha, and inflated it with air, ” this wheel eventually came to dominate the market. It was prized in particular for the smoothness of the ride that it provided; for unlike traditional solid wooden wheels, pneumatic tires “in every part of their revolution present a cushion of air to the ground or rail or track on which they run.”
Then, as now, pneumatic tires were made of rubber; and 125 years ago they proved so popular that experts perpetually predicted a “rubber famine.” Indeed, the early twentieth century saw a sustained rubber shortage brought on by “the spread of automobilism throughout the world, and the enormous use of rubber in the construction of motor tyres.”
The scarcity of rubber increased the price of tires, which rendered them unpalatable (and possibly unaffordable) for many people. Clearly, something needed to be done to “supplant the useful but costly rubber tyre on motor vehicles.” Inventors, scientists, and hacks around the world therefore turned their collective brain power to solving this problem. Their solutions, such as they are, can be traced in Australian newspapers from the late nineteenth and early twentieth century. Applications for patents also serve to shed light on these innovations, though, as one astute journalist noted, “Some of these patents have appeared in use and lingered for a while, while others have never been manufactured at all, and never will be.”
All these alternatives attempted to replicate the comfort provided by the pneumatic tire — for example, by layering the materials to build the tire or substances that mimicked the elasticity and shock-absorbent properties of rubber. Other major selling points, besides a reduction of rubber content, included fewer punctures and increased longevity of the tire. Obviously, none of them managed to supplant rubber permanently, but they constitute a record of creativity, hope, and even kookiness that can amuse and perhaps even inspire us today.
Leather/Pigskin
Leather in various forms was a perennial favourite to replace rubber. In 1903, the Scotsman John Muir announced that he had “invented a new and useful Improvement in Leather Tires for Wheels…I have discovered that the skin of the pig is the substance most suited for the purpose in view.”
According to the Examiner of Launceston, Tasmania, “Mr Muir is said to have sold the American rights of his process for £1 000 000.” I could not confirm whether this was true or not, but in any case it involved a special tanning method followed by waterproofing with “rubber or any suitable rubber substitute or composition, or artificial or mineral wax, or any suitable oleaginous substance or waterproof compound.” The end result was “a waterproof-leather wheel-tire composed of multiple layers of partially-unhaired and antiseptically-tanned pigskin, bristle-roots in said layers uniting adjacent layers, and a waterproofing composition forcibly compressed into the substance of said layers.”
While Muir’s pigskin tire did not in fact eliminate rubber completely, it did reduce the amount of rubber needed for each tire. However, a later invention from 1905–06 does not mention rubber at all. It consisted of sheets of chrome-tanned leather alternating with sheets of canvas “cemented together so as to form one common substance.” A perpetually hopeful journalist described this invention as “admirably adapted to replace rubber and to obviate all difficulties entailed by its use.”
That tire may be the same one over which the Sydney Morning Herald rhapsodised later that same month, saying that “this is the first time that it has been brought to such a state of perfection as to be claimed on an equality with the average rubber pneumatic. …The effect of moisture on the new tyre will be even less serious than upon India rubber, whilst there is less liability to puncture.”
Metal Springs
In the minds of some journalists, metal spring tires were a leading candidate to overtake their rubber counterparts, and indeed patents for such tires outnumber any other rubber alternatives.
The position and shape of the springs varied; Joseph Ridge envisioned multiple tapered springs, while others preferred a uniform width but varied their lengths.
Still others placed the spring on its side, creating — in the words of Emanuel M. Conrad — “an endless spring coil confined about the wheel rim and enveloped by a hollow casing.”
All these variations had one main objective: to “cushion jars and jolts under spring action instead of air action” and thus rival the pneumatic rubber tire in its comfort. Unfortunately, they never managed to do so. Nevertheless, spring tires became common in Germany during World War I, when a British naval blockade prevented the country from importing rubber. By the end of the war, the Kaiser was said to be the only person in the country with rubber tires on his car. Everyone else was relegated to “iron, even for the staff cars. They bumped over the roads and made a terrific noise, and could not go fast.”
Wood
In 1905, a solution to the “problem of tyre maintenance in the case of motor-omnibuses and trade vans” appeared: wooden tires! “The new tyre consists simply of sections of wood, resting upon a pneumatic cushion. A new process of seasoning and hardening wood…has made the tyre possible.” The wood acted as a protective cover for the inflated rubber tire, thus increasing the rubber’s longevity. (During World War I, the rubber tires of some Germany army vehicles were similarly encased with leather.)
Solid wooden tires also appeared. John Henry Knight built a tire of wood from the ash tree: “An excellent instance of the elasticity of wood is afforded by the archer’s bow, which retains its qualities for half a century century or more.” Knight’s tires were made using the “sectional” method, in which smaller blocks of wood were steamed and bolted into place alongside each other. Alternately, a single piece of wood might form the tire. However, such tires ultimately proved less popular and less practical.
Despite the “innumerable tests” carried out by Knight to show that his tires were “resilient and springy,” wooden tires generally lacked elasticity and had to be supplemented by steel springs to absorb the shocks. This addition “makes it possible to run on bad roads, as also along paved streets.”
Wool and Cotton
Unlike wood, wool and cotton are soft and, in the case of wool, elastic and springy — just like rubber. Perhaps these shared properties provided a source of inspiration to the person who decided to weave cotton tires “in much the same manner as cotton wicks for lamps. The tyre is continuous and endless, and of the form of a wheel, thereby enabling fitting to the wheel to be carried out with facility and celerity. The tyre has a greater bursting strain than any other material from which tyres are at present made, being equivalent to six thousand pounds per square inch.”
However, cotton was too popular for its own good. Already in 1909, “the world’s demand for cotton increases steadily…but the supply does not show signs of responding to the demand by a proportionate increase.” Cotton was therefore not a useful material with which to replace rubber — but not to worry! In 1913, “glowing accounts” from the United States reached Australian shores of “tyres made of wool, solidified under hydraulic pressure.” The usual superlatives followed: woollen tires boasted “ a resiliency quite equal, and a wearing surface far superior to that of the rubber.” They were also “much cheaper” and supposedly weighed 5–10 lbs less than their rubber equivalents.
Rope
In 1905, the Italian inventor Eugenio Cantono patented a rope tire for motor vehicles. The tread consisted of “rope [which] may be made of a vegetable fiber or of iron, steel, or other metallic wire or of other suitable material, such as leather, and in form may be made round of twisted strands or flat of plaited strands.” Benefits to the rope tire included a “good gripping-surface […] skidding or slipping upon wet pavements is entirely overcome and traction in mud or sand materially assisted.”
Several years later, an Australian sheep shearer inadvertently lent some credibility to Cantono’s claims about the suitability of rope tires for rough terrain. This anonymous man rode 100 miles on a bicycle with makeshift rope tires, and his feat became the subject of an admiring and awe-struck newspaper article: “He had no tyres on his bicycle, and could not obtain them where he was, so he decided to splice ropes into the rims, which he did, and rode the whole of the above distance without accident, although over very rough country.” Perhaps the rope tires really did, in Cantono’s words, “materially assist” the shearer over that terrain.
Paper
In the 1890s, paper tires for bicycles were all the rage — in the press if not in reality. The New Zealand Mail predicted that they would soon supersede rubber: “These tyres can be made cheaper than those made from indiarubber, two paper tyres costing only one-half or two-thirds that of a pair of rubber ones. It is claimed that they will last longer, as they are less yielding, and will not so easily be cut or punctured. Another advantage claimed is that they will be less liable to leak from frequent inflation.”
In 1906, an American (unnamed in the Australian press) released his version of the paper tire. He assured the public that such a tire was “especially suited for heavy vehicles by reason of its durability, and is not so prone to skid on a muddy surface as rubber.”
Yet paper tires remained firmly outside the norm for the next five years. Even by 1911, despite the best efforts of “an ingenious inventor” who had “undertaken to replace the strips of rubber used in motor tyres by compound strips of paper attached to each other by chemical binders under great pressure,” these tires had not yet taken over the world. Eventually, they were entirely forgotten. It was a sadly anonymous ending for an invention that “claimed to be as strong as steel, and as elastic as india-rubber, impervious to water and oil, and remarkably silent in action.”
Wheat
The fact that water can be added to wheat/flour and the resulting mass kneaded into an elastic dough may have inspired Mr W.T. Carr, who “foretells the making of rubber from artificially masticated grain, really from its treatment by a machine that will chew it with a chemically contrived saliva, and later press the mass into a rubber of the highest quality.”
Carr’s masticating machine began in “a small shed in his backyard” that was outfitted with “a coffee grinder and a kettle of hot water.” It was later developed to use a synthetic version of ptyalin, a component of saliva that helps to digest starch, and could manufacture six different grades of rubber: “№1 in the form of a thin solution for waterproofing, №2 in thicker solution for tubing and other flexible materials, №3 for tyres, №4 as a loaded substitute for linoleum, №5 still further loaded and hardened for paring purposes, and №6 again still further hardened for golf balls.”
There was truly no downside to this new wheat-rubber. Carr insisted that it was not a substitute to tree rubber — he felt that using the word “substitute” implied that it was inferior — but an equal, if not better, substance. As one journalist bluntly put it, “The proof of his assertion lies in the fact that his ‘rubber’ will vulcanise.” It also “cost considerably less than ordinary rubber.” Although some writers expressed concerns that using wheat to make rubber could lead to food shortages, optimism reigned: “It seems to be unquestionable that wheat-rubber is destined for a very high place in modern industry.”
The Magical Mystery Material
In 1912, Australian newspapers published the story of “a new kind of motor wheel, which, it is claimed, will completely do away with the rubber tyre.” Harold Richie and “Mr. Cropper, manager of the Sydney engineering works” could claim the honour of having discovered a material that would “soon supplant the present system of rubber tyres.” According to the article, they had already acquired a provisional patent and there was “abundant reason” for believing that their invention would be “found workable in practice.” Even more exciting, the new material was 75% cheaper than rubber.
However, just what these tires were made of is unknown. The article does not mention exactly how Richie and Cropper intended to render rubber tires obsolete; nor could I find any patents registered in Richie or Cropper’s names. Perhaps their materials and processes will be rediscovered in the twenty-first century…or perhaps they were all bunk to begin with.
Final Thoughts
More than one hundred years ago, necessity — in this case, a rubber shortage— was the mother of invention when it came to developing non-rubber tires. Desperation had a similar effect, as evidenced by the German civilians who outfitted their bicycles with tires of hemp rope, cellulose (paper), and wood during wartime. Yet despite the many alternatives, rubber remains the material of choice for tires today.
Would we be so creative, crazy, and ingenious as our ancestors? We might find out sooner rather than later, as climate change, war, and geopolitics show us what we’re made of — or rather, what our tires will be made of in the future.
