On Pneumatic Tires.

The pneumatic tire…stays a product whose traits usually are not simply predictable or understandable by typical engineering strategies.

– From Mechanics of Pneumatic Tires, printed by the U.S. Division of Transportation, 1981. Editor: Samuel Ok. Clark.

The invention of the wheel is usually put ahead as a pinnacle of human ingenuity, but it surely strikes me that the defining attribute of contemporary transportation programs isn’t the wheel however the pneumatic tire. In america, automobiles with tires carry twice as a lot freight as automobiles with out them. Tires have an outsized position in particular person transportation: The overwhelming majority of People commute on tires, outweighing all different modes by about fourteen to at least one. Tires are on our lawnmowers, these iconic symbols of twentieth-century middle-class independence, they usually’re on our e-scooters, maybe the zenith of twenty-first century globalization and consumerism.

The tire’s meteoric rise may need shocked nineteenth-century observers of the wheel, which took millennia to penetrate (and form) human tradition. Wheels emerged in numerous kinds between 3000 and 4000 BCE. But even despite its apparent utility, wheeled transportation remained costly, uncomfortable, and comparatively uncommon effectively into the early fashionable interval. Richard Bulliet writes that as late as 1570, the variety of four-wheeled carriages in Britain “could possibly be counted on one hand,” and even in 1814 there was just one carriage for each 145 British inhabitants. By comparability, right now Britain has about one automobile for each 1.6 folks – and roughly half of Brits personal or have entry to a bicycle.

The recognition of bikes, vehicles, and wheeled transportation usually has a lot to do with the tire – and the recognition of the tire owes loads to bikes and vehicles. In his 1846 patent, Robert Thomson described his “aerial wheel” – the primary pneumatic tire – as an “elastic bearing” mounted to a wheel, “rendering their movement simpler and diminishing the noise they make.” He wrote this simply two years after Charles Goodyear obtained the patent for his rubber vulcanization course of; rubber was, in the end, lastly good for making stuff, and Thomson had a prescient understanding of how vulcanized rubber might make wheeled transportation extra environment friendly and cozy. By far the dominant mode of wheeled transportation of the time was horse-drawn carriages, and Thomson ran a collection of checks to grasp how a carriage with pneumatic tires would fare. He described intimately how pneumatic tires made journey dramatically extra snug for passengers, and diminished the whole drag on the automobile by as a lot as 68%. In time the advantages attributed to tires would multiply: They permit a lot increased speeds of journey; they enhance traction dramatically; they permit a automobile to keep up traction even when the street floor is uneven; they will tremendously cut back the sound of the wheel rolling over the bottom.

However Thomson was too early, and his carriage tires had nearly no impression on the course of historical past: As Henry C. Pearson famous in 1905, “they don’t seem to have come into use besides as a curiosity.” Thomson himself additionally appears to have turned his consideration to different issues; he later moved to Java and invented an improved fountain pen. An unimaginable technological breakthrough had occurred, however no one needed to place pneumatic tires on their carriages.

Forty years handed, with pneumatic tires nowhere to be seen. Stable rubber tires gained some reputation for farm automobiles; Thomson himself patented a strong rubber tire in 1867, six years earlier than he died. However the huge factor that modified round that point was the truth that people started pushing themselves round on wheels – as a substitute of being dragged in carriages by horses.

Velocipedes – often called “boneshakers” within the US – had been a big step in the direction of the fashionable bicycle, incorporating not simply two wheels but in addition a crankset and pedals, which allowed the rider to use power on to the entrance wheel as a substitute of pushing off the bottom like a scooter. One French producer alone produced 2 hundred velocipedes a day in 1869 – the next manufacturing charge than any auto producer would reach for the following forty years. Heavy, crude, and wildly well-liked, velocipedes would function the impetus for a variety of technological developments, from radial ball bearings to improved street surfaces to, in 1888, the reinvention of the pneumatic tire by John Boyd Dunlop.

Dunlop – a veterinarian who took a wildly profitable shot at enhancing his ten-year-old son’s tricycle – noticed what Thomson had earlier than him: Wheeled automobiles decelerate once they go over bumps, and the smoother their journey is, the extra environment friendly they’re. When wheels roll up the entrance of a bump they switch somewhat kinetic vitality into gravitational potential vitality; once they roll down the again aspect of the bump some – however not all – of that switch is reversed. Essentially the most environment friendly wheeled automobiles journey on the smoothest doable surfaces (prepare tracks) on the roundest doable wheels (railroad wheelsets); their movement might be described virtually as a straight line, they usually lose little or no vitality to being jostled round. However bikes, vehicles, and e-scooters should take care of far more assorted surfaces, and each time they bounce up and down, somewhat little bit of their kinetic vitality is dissipated as warmth. A bumpy street floor vibrates the bike and its rider, and that vibration causes every little thing – the tires, the construction of the bike, and the muscle tissue and skeleton of its rider – to actually heat up.

It warms my coronary heart to consider Dunlop – forty-eight years outdated, with a horse-shoeing enterprise that employed a dozen folks – springing to motion to assist his child’s trike go sooner. As a 1981 Dunlop-sponsored e book summarizes, “the boy’s report on the efficiency of the brand new machine on its new tyres was most encouraging.” At this level vulcanization was a mature expertise, and the bicycle business was large enough for Dunlop to think about a large marketplace for his invention. He promptly filed a patent (it was later invalidated) and inside a 12 months was supplying crude pneumatic tires to bicycle racers in Belfast.

In 2014, I visited a Taiwanese tire manufacturing facility as a part of a bicycle sourcing journey. On the time I had a reasonably good deal with on the manufacturing processes required to construct bike frames, however the sounds, smells, and general texture of tire manufacturing all felt overseas. Tires – whether or not for bicycles, vehicles, or every other goal – are made by way of principally the identical strategies that Dunlop utilized in 1888, by build up uncooked rubber on a cloth casing and a pair of wire beads after which vulcanizing the whole meeting. The tire business has dominated world rubber manufacturing principally since its inception; right now it consumes roughly three quarters of worldwide pure rubber manufacturing, and similarly massive portions of artificial rubber. Pneumatic tires are the killer utility for vulcanized rubber. They permit us the pliability to journey over all types of surfaces, from asphalt and concrete right down to gravel, grime, and sand. Pneumatic tires permit our transportation infrastructure to be versatile, dependable, and cozy, and allow us to journey to locations that we’re both unable or unwilling to get to by way of rail, ship, or air.

See Also

A 2024 Plea for Lean Software program (with working code)

It’s tough for me to conceive of a world with out pneumatic tires. They permit a number of the issues I get pleasure from in life. Then once more, tires are a part of a particular technological ecosystem; simply as they had been impractical earlier than the bicycle, it stands to motive that they could be impractical in some unspecified time in the future sooner or later.

SCOPE CREEP.

• Scope of Work’s workshop scavenger hunt kits are again in inventory! Get yours 🔜 here.
• This situation relied closely on The History of the Pneumatic Tyre, 1981, by Eric Tompkins, and Rubber Tires and All About Them, 1906, by Henry C. Pearson. For far more on rubber, try our (growing!) collection of feature articles on the subject. I additionally referenced my copy of Bicycling Science, wherein David Gordon Wilson explains the forces that have an effect on fashionable bicycle efficiency. Appropriately, his rationalization focuses on aerodynamics, and it generally feels as if he introduces different components principally to clarify how small they’re compared. Wind resistance dominates the power-speed relationship on fashionable bicycles, and the largest think about wind resistance is the frontal space of the bicycle owner and the bicycle they journey. The load of the bicycle, the standard of its bearings, and the dimensions and mechanical properties of its tires are all surprisingly insignificant. For those who, expensive reader, wish to go sooner in your bike, the best method of doing so will virtually definitely be to scale back your frontal space. However entering into an aerodynamically environment friendly place might be fatiguing, and over the previous decade or so, an increasing number of cyclists have used supple tires as a strategy to cut back rolling resistance and improve consolation. Certain sufficient, David Gordon Wilson does word that the diminished drag that comes from putting in low-loss tires “comes at maybe the least diploma of ache” of any of his different suggestions.
• The shift from inner combustion engines to electrical automobiles can be a great step for atmospheric CO2, however it’s possible that EVs will produce increased ranges of PM2.5 emissions – which, as this 2022 study in Los Angeles confirmed, are more and more pushed by brake put on and tire put on.
• Moquette is a sturdy pile material, typically comprised of wool, which is used to upholster the seats and flooring of commuter rail vehicles. Moquette is used prominently within the London Underground, and the London Transport Museum has a ton of information about the textile and its history on their website.
• Snecked masonry is a kind of stonework wherein roughly rectangular stones of combined sizes and proportions are organized to type an irregular sample.
• A couple of weeks in the past, a federal appeals court held that when a privately-developed commonplace (like ones for highway bridges, motor vehicle turn signals, and bike helmets) is adopted into public regulation, it might probably then be disseminated freely with out threat of violating its copyright. ‘“In a nation ruled by the rule of regulation, non-public events haven’t any enterprise controlling who can learn, share, and converse the foundations to which we’re all topic,” EFF Authorized Director Corynne McSherry mentioned. “We’re happy that the Court docket of Appeals upheld what different U.S. courts, together with the Supreme Court docket, have mentioned for nearly 200 years: Nobody ought to management entry to the regulation.”’
• For those who’re available in the market for a half-hour TV present that’s hilarious and honest and completely shocking, my highest advice goes to Reservation Dogs, which simply completed its three-season run on FX/Hulu.

Thanks as at all times to Scope of Work’s Members and Supporters for making this newsletter possible. Thanks additionally to Paul and Ziggy for sending hyperlinks.

Love, Spencer

p.s. – I’ll be again with extra on rubber within the coming weeks 😉
p.p.s. – We care about inclusivity. Here’s what we’re doing about it.