As a mechanical engineer, this statement baffled me. All manufactured technology exists in the context of the manufacturing capabilities available to the designer. The manufacturing tech had to be tremendously complicated before a decent bike could be made. Hollow steel tubes aren't simple. Ball bearings aren't simple. There is a reductionist viewpoint among "theory" people that misses the trees for the forest.
Good steel, in quantity, only goes back to 1880.
Lots of things that "could have been built in antiquity" foundered on that basic fact. Before Bessemer, steel was as exotic as titanium is now.
The alternatives are not good. Cast iron? Too heavy and too brittle. Wrought iron? Maybe, but not that great. Lead? Too soft. Brass? Could work, but expensive. A king's kid might have had a brass bicycle.
If the iron workers of Cizhou, China, who had an air-blown steel making process by about 1100 AD, had made the next step to a Bessemer converter, history would have been completely different. They were close. Right idea, limited steelmaking capability, existing iron industry. Coal was available, but apparently not too easily.
The few places in the world with easy access to both coal and iron ore started the Industrial Revolution. Then came railroads, and the resources didn't have to be so close.
We think a computer is an impressive piece of technology, but many of the things around us that we consider less than mundane are just as incredible if we look just a couple hundred years back.
Making the first precision screw requires a "screw originating machine". This is a special-purpose device which can make a better screw than the ones used in building it. Then you can install the first precision screw in a lathe and make more screws in harder metals. This is how precision is bootstrapped.
> Making the first precision screw requires a "screw originating machine". This is a special-purpose device which can make a better screw than the ones used in building it.
I hadn't realized screws would be needed to create a screw-making machine. I love that we have machines that make better versions of their own components, something I never even thought to think of!
In our current economy, that reversion would be even more painful. In the short term, as much as I hate the US military, their "freedom of navigation" guarantees are essential. In the long term, every nation/bloc should make sure it has the materials to re-bootstrap if necessary.
Here in Korea, we just had to scramble because Japan decided to limit photoresist and high-purity HF exports. I count the scramble as a good thing for national self-sufficiency.
My apologies for going way off topic.
For fans of that podcast, it's one of the best single episodes. Dan Carlin has a particular style, which is not for everyone, but fans know what to expect.
That's why it pains me when I see activists crying for correcting the wrongs at all costs, "justice" at the cost of "order". It's ultimately a self-destructive approach that's akin to cutting off the branch you're sitting on, after first setting it on fire.
The biggest threats to the current order are companies and politicians that refuse to address our unsustainable level of pollution, which is pushing our climate out of balance.
They're the people advocating for a "starve the beast" approach to governance, literally trying to create a financial crisis just to get a few percent taxes shaved off their bottom line (and probably think they can profit off the crisis too).
They're the people pushing for increased gerrymanding and census manipulation, which radicalizes politics on both ends of the political spectrum, shuts out people in the middle, and erodes faith in our institutions on the long term.
These things are by far the biggest threat to the long term stability of the current order in the US.
The knowledge, How to rebuild the world from scratch
We can't do a Saturn V today. We might be able to do a Saturn V equivalent, though, as both NASA and SpaceX are retracing the steps towards heavy lifters.
“Imagine waking up the next morning and the world totally forgot all knowledge on Linux Kernel, and you are now tasked to release the next major version with major changes / improvements”
And remember the documentation and tests we have on Saturn V is certainly not as great as what we have on Linux kernel.
They're having to analyse the garments in medical scanners to work out how the fabrics work.
The idea that technology that enabled the equivalent of the space race could be lost within a century is quite sobering.
I first need to finish and ask someone to proofread my long overdue post on my views about advertising industry.
With no readily-accessible source of energy, we would never be able to reboot. And everything readily-available has already been mined. We now drill deep below the ocean surface for oil.
The Ecotechnic Future, The Retro Future, The Long Decent, Not the Future we ordered - all great books on what will happen if these systems crumble from resource depletion.
As much as I want disagree with his views, they look more sound every day. He is actually doing a follow up series on these topics on his blog (Ecosophia) currently.
Consider also the amount of people needed all across the industries and supply chains of any product you know. I don't have hard sources, but I fondly remember this essay by Charles Stross. TL;DR: how many people does it take to maintain (not improve) current technology level of our civilization? Charlie puts it at 100 million to 1 billion.
And now think of the economies and infrastructure needed to just feed these people. We hit 1 billion around 1804, which is far in the industrialization process, and most of these people weren't working to support the technology levels anyway.
For some insights, I recommend tracking down and watching Connections. It's an old show, from the era where TV shows actually made sense, and it drives home just how much our current technology is dependent on right combinations of social, economical and technological conditions.
EDIT: fixed site reference in .
 - http://www.antipope.org/charlie/blog-static/2010/07/insuffic...
 - https://en.wikipedia.org/wiki/World_population_milestones
 - https://en.wikipedia.org/wiki/Connections_(TV_series); I hear you can find it on a site that starts with "daily", and ends with "motion.com".
Really when you get down to it, like computers, tools are used like 30+% of the time to build other better tools. Jigs, more accurate cutters, measurement devices, etc. With code that's things like test frameworks, rpc mechanisms, version control, code gen, etc. In fact in software engineering you're usually seen as a better engineer if you build things indirectly (frameworks) instead of mass production of the solution.
Check out the home machine shop series to see how you'd build up a tech stack from basically scrap metal and wood and Sand.
The Metal Lathe (Build Your Own Metal Working Shop From Scrap Series Book 2) https://www.amazon.com/dp/B007USU8HU/ref=cm_sw_r_cp_apa_i_Gh...
The lathe is pretty much the ur-machine, and a lathe is really just screws
here's a link to the text https://www.sefaria.org/Pirkei_Avot.5.6?lang=bi&with=all&lan...
The form of the verb translated that God "rested" is in fact progressive in the original Hebrew.
A better compiler can compile itself more efficiently, same for CPU/chip layout systems.
Absolutely. Otherwise, all compilers would be written in Assmebly. Most compilers used today are written in C and the compiler for C (GCC) is written in C itself.
The C language was also written by Ken Thomson, because he was unhappy with the BCPL language, so the compiler for C was originally written in B. So on and So forth.
More Recently, the initial compiler for Rust was written in OCaml but is now written in Rust itself.
Its been a while, and I think it was gcc 7.x timeframe, and IIRC, you had to have at a min, gcc 4.x available to bootstrap, and it took something like 3 separate bootstrap iterations to get the final compilers was like 4-6 hours if memory serves.
There is certainly a major milestone in each new language though, when it becomes feature complete enough to write its own compiler.
He asked about standard screw sizes and was told that there were no standard sizes or "in stock", and he should just tell them what size he wanted because their supplier just makes whatever size screws they need.
This is how compilers for example are made. You initially compile the improved source code of a compiler on the previous version.
I wonder if there is an ancestry trees (or I guess chains) somewhere of the major compilers out there?
But for real, interesting read. Thanks for linking that.
Would love to see some applications of such a thing.
I learned that in 1751, Vaucanson made this full-metal lathe: https://artsandculture.google.com/asset/metal-turning-lathe/... that was a kind of breakthrough and the ancestor of modern lathe, one of the first precision machine tool. Add that to his automata and his invention of punch cards to program looms and I am now realizing how much of a Da Vinci that guy was.
See the excellent book "Foundations of Mechanical Accuracy" by Wayne Moore of the Moore Tool Company for details.
There recently was an article on HN that fabs install microphones and other environmental sensors everywhere and use deep-learning to extract QA information from the sensors.
People would burn scrap lumber to recover the nails.
Which reminds me when I was a little kid people would carefully pull the nails out of old boards and save them.
You would be able to offer great advice about washing hands or the solar system generalisations. But actually create something to show people....even the simplest things would be beyond most of us.
Tools required: tin snips and a hammer.
A battery can be made from a jar, lemon juice, and two electrodes.
Believe me, as an 8 year old, my skills were limited to using a hammer to mash my thumb with. :-)
Electromagnets substituted for magnets, and bearings were a dent in the sheet metal that the point of a nail sat in and turned. Simple and effective.
Once you showed this to a medieval craftsman, they could reproduce it and start improving it.
The version I built was far simpler, and used electromagnets instead of the magnets, but you can see the general idea.
I didn't design it, I don't know where the Den Mothers got the design from. But I found it fascinating, as you could see and feel how it worked.
I built several of them. One day, I got a little bolder and replaced the battery with an A/C cord. The motor buzzed loudly and burst into flames. I learned about alternating current that day :-)
Even 21-century craftsman would find that impressive.
The merchants were despised, as merchants everywhere are; the rich farmers weren't. And a hereditary distinction between commoners and nobles was gone by the tenth century.
So I'd want to hear a little more context to the claim that "the iron industry was shut down because of the effrontery of commoners getting rich there".
The right take away after reading Stark is to become skeptical of a non-trivial amount of historical scholarship regarding the issues he covers, and skeptical of Stark as well.
Stark says, "Eventually, Mandarins at the imperial court had noticed that some commoners were getting rich by manufacturing and were hiring peasant laborers at high wages. They deemed such activities to be threats to Confucian values and social tranquillity[sic]. Commoners must know their place; only the elite should be wealthy. So, they declared a state monopoly on iron and seized everything. As Winwood Reade summed up, the reason for China's many centuries of economic and social stagnation is plain: 'Property is insecure. In this one phrase, the whole history of Asia is contained.'"
Footnotes for sources list "Hartwell 1966, 1967, 1971, McNeill 1982" for the info on the iron industry, and "Reade 1925: 108" for the quote.
"Hartwell 1971" resolves to 'Hartwell, Robert, 1971. "Historical Analogism, Public Policy, and Social Science in Eleventh- and Twelfth-Century China." The American Historical Review 76:690-727.'
Hartwell 1966 is "Markets, Technology, and the Structure of Enterprise in the Development of the Eleventh-Century Chinese Iron and Steel Industry." The Journal of Economic History 26:29-58.'
(No Hartwell 1967 is listed in the bibliography.)
McNeill 1982 resolves to 'McNeill, William H. 1982. The Pursuit of Power: Technology, Armed Force, and Society Since A.D. 1000. Chicago: University of Chicago Press'
Finally, Reade resolves to 'Reade, Winwood. 1925. The Martyrdom of Man. London: Watts.'
I'm not sure that Reade is important for more than the quote. I suspect that Hartwell and McNeill are the source of the actual info on what happened in China.
And, presuming that Stark summarized adequately, the problem may have been hiring peasants for high wages. That may in fact have been somewhat disruptive to the existing social order...
Vikings transported Crucible steel all the way from Afghanistan to make high end swords. Damascus steel(actually manufactured in India) and then forged into weapon in Damascus.. etc
There got to be other reasons. Better or equivalent to Crucible steel but en masss.. you can have forged plate for everyone, horse full armor, heat treated crossbow bolt heads etc.
But there was never a Chinese ideological opposition to peasants becoming rich; the theory advanced by AnimalMuppet makes no sense.
The assumption here is that every thing works in a clear way so you can see the military or whatever advantages of a particular phenomenon. Now I don't know if AnimalMuppet is literally correct that the bureaucracy simply shut down the steel industry -- but if it happened it would be because all that cheep steel was not being used for obvious things, like the imperial army, but for other unexpected uses. Maybe arms and armour still had to be made the old fashioned way anyhow, so there was no immediate military advantage.
More likely, things were subtler. Things innovations can strangled long before their importance is clear. Imperial China had a vibrant merchant class, but it isn't the kind of place that is likely to tolerate the "disruptive innovation" which fuelled Britain's Industrial Revolution -- where a bunch of upstarts come and do things with unexpected things. Even modern China (or for that matter the modern United States) struggles with it.
Bernhard J. Stern, "Resistances to the adoption of Technological Innovations" (1937)
Bearings could have been polished and oiled wood. The frame, wood. The hinge of the front wheel, brass or another small bit of steel. Transmission could be a leather belt. Wheels, wood again.
Would such a device somehow emulate a modern bicycle? Very likely.
Would such a device be practical, reliable, fast, to say nothing of comfort? I greatly doubt it.
But efficient enough to go some distance, reliable enough not to need a full-time repair-man, and cheap enough to be sold to people who didn't already own a horse & carriage? That needed lots more technology.
You also need people to ride it. It wouldn't fly as a palace amusement because the king (and more importantly the little prince) would keep falling off. They won't have an incentive to value the skill until there is a horde of middle-class, 19th century, hipsters showing him up.
A circus act is more plausible, but only if there's some continuum of other simpler circus equipment leading up to this rather sophisticated bit of engineering.
I suspect you could make a perfectly acceptable modern bicycle with 18th century technology, albeit not as durable. Metal axles aren't much of a problem. Light and strong wheels are trickier, but you could get away with solid wooden ones, or emulate modern spoke systems with sturdy leather strands. The chain is difficult point - leather won't cut it as you need immense tensile strength and rigidity - but if you didn't want to meticulously hand-craft a modern chain (possible but tedious), a direct-gear solution might be practically possible.
No, what was missing was the very concept that it would be a worthwhile thing to attempt to build. It would have taken an incredible visionary to follow the above steps, especially in a world where the poor quality of roads made such a device of questionable value. And anyone rich enough to afford such a thing was doubtless rich enough to afford a horse carriage - who in that set would aspire to pedal through the mud?
tl;dr expensive, flimsy bicycles are completely useless in a world with poor roads and deep wealth inequality.
You make a last great point with this.
Without paved roads, rubber, decent springs; all of the shortcomings are amplified. The gear drive works, but if you have a wood wheel, with a wood axle, w/ wood cogs, the tolerances to be both comfortable and effective on cobblestone or dirt would be troublesome.
as a one-word piece of supporting evidence, let me just say - Boneshakers.
Leonardo da Vinci could have built a Chukudu in 1490.
Leather is good enough for motorcycle drive belts. Nowadays belt drive bikes use cogged composite belts, but once upon a time they were leather.
A find of the past few years has been Joseph Needham's truly epic Science and Civilisation in China. Begun in 1954, still in production -- the series is not yet completed, 7 volumes, 27 books. Simon Winchester (also author of The Perfectionists, mentioned in this thread, has an excellent biography, The Man Who Loved China.
And bamboo really is a hell of a material. The breadth of vocational materials science they had was staggering.
A printing press isn't as useful if you have to manually verify and fix the types ever other print.
It brings to mind one artifact of letter construction being based upon the writing method - cuneiform vs ink pen letters for instance.
Archimedes could have built a velocipede, using mostly wood, same tech as ox-driven carts, just the wheels being lighter and more narrow since the load is much less, and it would have worked fine.
I'm just not sure about road surface quality back then. I suspect that was a bigger limiting factor.
Also, bikes are kind of a city thing. On the country side, horses work just fine.
Perhaps that's just my experience.
You're right about horses. Oxen were the preferred power source to move goods. Sometimes donkeys. Horses were used for the same purposes, but that indicated the owner was definitely not on the lowest rung on the social ladder. The context here is the Eastern Bloc decades ago.
It was a limiting factor for modern bikes too, sealed roads were invented to make cycling easier.
Haven't they made working bicycles with wooden frames?
It is the little parts that matter. Not just screws; really-spherical ball bearings, ceramic-hard bearing races, micrometer adjustment.
Without good bearings, friction and wear make it a short-lived toy.
Albeit such devices would be “powered” by animals rather than people. So the friction of baring-less wooden joints was probably less of a concern.
Well that still leaves wood.
And bicycles made out of wrought iron would work perfectly fine. First bicycles were made out of wood and durability wasn't their main issue.
"Technology factors are more convincing to me. They may have been necessary for bicycles to become practical and cheap enough to take off. But they weren’t needed for early experimentation. Frames can be built of wood. Wheels can be rimmed with metal. Gears can be omitted. Chains can be replaced with belts; some early designs even used treadles instead of pedals, and at least one design drove the wheels with levers, as on a steam locomotive."
"Second, advances in materials and manufacturing were probably necessary for a commercially successful bicycle. It’s a bit hard, from where I stand, to untangle which advances in design were made possible by new materials and techniques, and which were simply sparks of inventive imagination that hadn’t been conceived or developed before. But the fact that people were willing to put up with the precarious high-wheeled design indicates to me that pneumatic tires were crucial. And it’s plausible to me that advanced metalworking was needed to make small, lightweight chains and gears of high and consistent quality, at an acceptable price—and that no other design, such as a belt or lever, would have worked instead. It’s also plausible to me that wooden frames just weren’t light and strong enough to be practical (I certainly wouldn’t be eager to ride a wooden bicycle today)."
Take even just a single part from it, like the chain for example probably represents centuries worth of technology. Each link has to be uniform to operate smoothly on a chainring or sprocket, which indicates some form of mass production.
Chains must be hardened to withstand stress, resist stretching. Soft steel would wear and deform too quickly.
Each link is in itself a complex component composed of a uniform bushing and pin shaped oblong symmetrical down the center and also quite small. It must pivot smoothly.
I doubt there are many people, even skilled people, who could make a complete bicycle from raw metal stock.
He attempted to build the basic components of a toaster from scratch. Smelting metal, molding plastic, etc. The book is a tough recommendation because he sortof gives up on the later parts and limps to a finish, but overall its a fascinating look at how difficult these processes are if you build them up from scratch.
One of the more famous videos is where it takes them ~$1500 and 6 months to make a chicken sandwich and they still used a lot of equipment that they didn't make themselves.
it takes them ~$1500 and 6 months
to make a chicken sandwich
I'm now convinced that almost no software engineer is worth its title unless he made some physical apparatus on any complexity. Even a pair of scissors.
As with usability testing, small-n samples, say three to five, go a long way.
Do you have cross-domain expertise yourself?
As for ball bearings these are incremental improvements not a necessity (see horse chariots and carriages with wheels used for millenia before we had ball bearings). For another example see medieval wooden windmills - all cogs and bearings made from wood with some animal fat and skin for bushings and lubrication - worked well enough for centuries.
> Tutankhamen's chariots give us an opportunity to study the details of wheels and axles. The aspect that is most striking to a present-day engineer is that the axles were made of wood and the wheels bad wooden journals. The favored materials were elm and birch, which were imported because neither wood was native to Egypt. Anyone accustomed to modern practice finds it hard to believe that wood-on-wood could function as a bearing at all. This primitive arrangement was improved in a few cases by the addition of a leather bushing. Lubrication in the form of animal fat or tallow is known to have been used, although the exact composition has not been determined.
First mass-produced bicycle (velocipede) had no ball bearings until a few years later.
>> Anyone accustomed to modern practice finds it hard to believe that wood-on-wood could function as a bearing at all. This primitive arrangement was improved in a few cases by the addition of a leather bushing. Lubrication in the form of animal fat or tallow is known to have been used, although the exact composition has not been determined.
You'll notice that your examples involve a lot of power driving the mechanism - a team or horses or a windmill can overcome the kind of friction a wood-on-leather bearing implies. If you've ever ridden a bicycle where the fender was rubbing on the wheel, you'll know that human power is much more limited.
I think people vastly underestimate what you can do with very simple "naive" technology.
 Yeah it uses aluminium spacers on the chain, but you can do a bicycle without a chain.
Your "proof" is unconvincing.
1. The bike looks super wobbly and seems like it takes a lot of effort to just make it function properly. Yes, it is an example of a wooden bicycle, but it is not an example of a useful wooden bicycle. It seems like it probably has a pretty short working life and low speed. In short, it's worse than just running.
2. The bike is being run on a paved road. All of my earlier criticisms get magnified by the stress of taking the bike off road. Yes, dirt roads are a thing. No, they are not nearly as smooth as asphalt. Also, much like carts, a bicycle like that would start to put ruts in a dirt road.
But there were wooden bicycles without ball bearings in real-life history and they worked with the infrastructure they had. How well they worked is a different thing, but still it proves "no tech to build a bicycle" isn't the reason we waited for bicycles for thousands of years.
We had people jumping off towers with wooden wings for centuries before aeroplanes were made after all ;)
It would be perfectly possible for Romans to make bicycles from technological POV. Just wouldn't make sense because 2 slaves with some chair on sticks were cheaper.
BTW - first real world mass-produced bicycle added ball bearings after several years:
> On the new macadam paved boulevards of Paris it was easy riding, although initially still using what was essentially horse coach technology. It was still called "velocipede" in France, but in the United States, the machine was commonly called the "bone-shaker". Later improvements included solid rubber tires and ball bearings.
Anecdotally, on a bike ride recently, on a modern bike, hopping an inch curb snapped a chain.
I think the problem was roads. If you combine bad (or nonexistent) roads with airless hard tires, the result is much much less useful than any modern bike on any modern road.
The first bikes were indeed wooden with wooden wheels. No ball bearings, no hollow steel tubes etc. But streets.
I could now say something about how engineers are so specialized in their perspective they cannot judge things without bringing current conventions into it but hey, every profession comes with it’s weakness.
Highly skilled artisans could make one-off pieces fit together exactly. Doing so at scale was prohibitively expensive, because machine tools hadn't been invented that let you precisely machine things identically. So, if you had a broken bicycle, you'd need a skilled artisan just to repair it- off-the-shelf parts were impossible. Every single bike would have been a unique object. This is how guns, ships, clocks, and basically everything was made before reliable methods of achieving precision were invented at the dawn of the industrial revolution.
The antikythera mechanism had inherent looseness in its hand-wrought gears which greatly limited how accurate it could have been. https://en.wikipedia.org/wiki/Antikythera_mechanism#Accuracy
(source: this book, which I gather is pretty accurate, if pop-history https://smile.amazon.com/dp/B072BFJB3Z )
Ancient technology was neither accurate nor precise. Making two specific things fit (e.g. THIS dowel pin in THAT hole in a brass plate) does not require precision in the actual sense of the word, you can achieve the goal by consistently small iterations (ex: grinding the dowel down until wanted fit is achieved).
Precision (all my threads are the same) and accuracy (and they fit with the thread from every other machine shop) are what made the industrial revolution. Ancient technology had neither of those.
Dually, Romans were known for their extensive roads system. My family home sites directly below the Ancient Roman frontier in Germany, where you can climb a mountain and still find a 10 foot wide stone road they built 2000 years ago mostly intact
They often use customized bikes for that to keep from shaking their fillings out.
There was basically no rich middle class which had the time and money to fool around with individual transportation, and the other classes had either no real reason to want this or it was pure luxury.
I also would think such people existed elsewhere in the world centuries ago.
Chinese wheelbarrows are the real endpoint of pre-industrial transportation.
Pretty much all modern rideshare bicycles do not have pneumatic tires, FWIW. Ride quality suffers, but it's not an awful tradeoff for short trips with whatever squishy compound they use now.
Carriages used to have suspensions (made from some elastic whale bone I believe).
If someone would attempt to build a bicycle in a time of carriages with carriage wheels, I would then expect this person to also copy (at least in analogy) the suspension systems for carriages of that time, if not on the first try at least on the second...
It's just some of the cheap dockless purveyors that use non-pneumatic tires, and these companies have been dropping like flies. The docked bikeshares by contrast are still (slowly) expanding with their superior, but admittedly more expensive, bicycles.
Anyone with the means to pay would much rather use an animal-pulled cart instead of literally making an ass of himself.
Or just ride a horse like a gentleman. (Until the 'mad dogs and Englishmen' craze hit.)
As a counterpoint see the marine chronometer for measuring longitude. Clocks had been around for centuries so easy right? 
Making something strong/reliable is easy, making something precise is 'easy', making something strong/reliable and precise, oh and preferably lightweight is hard.
You do have a good point about roads though. In fact in the UK the first push to tarmac the roads came from cyclists, not from motorists. And the first tyres were for a certain Mr Dunlops sons bicycle.
It wasn't until the mid 1800's that the people who would want a bicycle could afford one if such was available. You had a middle class with disposable income. And simple mechanical contraptions like bicycles were cheaper. Because steel got about 20 times cheaper from 1860 to 1890. And things like chain drives had become industrial commodity items.
What bothers me with such speculative and unsupported history is now it will likely be thought true. Everyone believes that there were two sleeps per night in the past or that doctors brought women to orgasm to relieve stress. These ideas have little substantiated documentation and are hard to believe yet they are repeated by know-it-alls frequently.
Have you ever ridden a horse? You have to have balance to avoid falling over. And if you have ridden one, it sounds like you've never ridden English-style.
>Further the horse is firmly planted on the ground on four legs.
Only when it's standing still. Try riding one while it's jumping over things.
I recall in my freshman physics classes asking my professor "why are all the modules using inclined planes and pulleys? wouldn't we be able to learn better if the problems involved something we're actually familiar with in everyday life like a bicycle?" (I attended the university with the most bicyclists in the world)
I only needed to see his reaction to realize that a bicycle is pretty damn complex.
Lots of people dismiss the Wright Bros as "bicycle mechanics". They kinda miss that lightweight bicycle technology, like chain drives and steel wire, were essential for their working airplane.
Who could ever believe such a thing could happen?
The invention itself might have even occurred, or parts of it. If you pressed hard enough, maybe you might have gitten a decent prototype built in the bronze age.
History has to take its course, in a sense. It has to be.practical and economical to manufacture, acquire and use one. A major part of that is what it takes to build one that's good and cheap enough. Another part is the path (roads, good steel parts like hollow tubes). Then it needs to be invented in a way that can lead to some decent number being made, demand of some sort considering that it still sucks. Enough people need to learn to ride one... There need to be engineers around with an interest...
It's dense with trees, but forests assume trees are inevitable. Nothing here is really. Maybe the invention is, on some level. But things usually need to be invented into existence over many iterations, events and chains before they totally stick.
Assembling a wheel from parts is beyond most people, including many bike mechanics. In fact most wheels are assembled by machines, else labor costs would be too high.
Used to be it was mostly serious amateurs and professionals that had them hand built. They’re more reliable, but I think it’s more to do with the combinatorial explosion of parts. Machines are for making 5000 of something, not one.
And even the reliability will fall at some point (maybe already, I’ve been out of the loop so long) The human picks up on things that don’t seem right. But if you built enough telemetry into the robot, you could measure all the elastic and inelastic deformations and probably reject/reassemble the wheel based on information a human couldn’t or wouldn’t track.
Just how shitty wheel would be admissible here? A wooden octagon?
Having rewound electric motors w/ no repair manuals avaliable & laced rims w/ repair manuals & directions from the spoke manufacturer, rewinding an electric motor is far easier to successfully accomplish.
This discussion is similar to flawed arguments about evolution. It assumes that at any given point in time, there was an exhaustive search of solution space (in this case for personal transportation). In discussions of evolution, people often propose that a particular solution occurred because it was optimal in some way.
But neither evolution, nor technology development, involves an exhaustive search. Things happened by chance, and some things were not tried as early as they might have been (or they were tried and tried and found lacking in some way), until, by chance, the right conditions allowed the technology (or evolutionary trait) to emerge.
The role of chance is often under appreciated.
I once tried to figure out how to make iron from nothing. There are several "from scratch" guides on the internet, but all of them include "buy these needed chemicals from a supply house".
I suspect the answer is complexity. There are a bunch of inventions all together in a bicycle. From the frame to the spokes to the tires and headset, there is a lot of IP there.
Bicycle can be very simple. You need just two wheels (can be made of wood with some steel support, just like a wagon wheels) and some frame to connect these (again can be made from wood). You do not need any bearings or even a belt - you can connect pedals directly to the front wheel (as was done in early design).
All of this can be made with simple carpenter and smith tools.
Disclaimer: I lost my 20+-year-old baby-blue R800TT to frame damage that I bought while making $4.25/hour. #SadDayForMe
Of course, some commercial aircraft are now getting CF parts, but they're still mostly Al.
If memory serves, even the London Science Museum's partial reconstruction in the 1980s was a massive challenge of engineering.
Wright brothers were bicycle mechanics, before they pivoted into inventing heavier-than-air flight craft.
The wheel existed before ball bearings - why are they necessary for bicycles? (is it an efficiency thing, for human powered?)
The safety-bicycle chain requires cheap precision mass engineering, but rope, rubber, axial rod (as in a car), or interlocking gears also work. Or direct, as in a penny-farthing. Or, no wheel power transfer, but push along with your feet, as in the Kirkpatrick bicycle.
Usually there are a lot of great ideas, but availability of materials in quantity, or a key part is what is missing, sometimes for centuries, and often comes from someplace you might not expect.
Conversely, what would the world look like today without steel? No airplanes? No WWI nor WWII? No huge panamax ships? No global markets?
It certainly is amazing how people take for granted the marvels of current technology.
If anyone thinks these tires aren't important, then why are almost all vehicle tires still pneumatic?
Couldn't you just use anything sufficiently round and uniform and Mohs-hard, given a lubricant oil to protect it from wear? Glass marbles? Pearls? Rocks after a ridiculous amount of tumbling?
(Yes, you can make something that looks like a ball or roller bearing even on a cheap 3D printer, and it may even have less friction than the thing that looks like a plain bearing/bushing you can make on the same machine, but it's not going to roll freely and take a load.)