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Bicycle Technology (1973) [pdf] (veterancycleclublibrary.org.uk)
60 points by BeniBoy 67 days ago | hide | past | web | favorite | 31 comments



> The thin-walled tube of circular cross section is a most efficient structural member; it can resist tension or compression, bending, torsion, or the combination of stresses that are exerted on the frame of a vehicle. Although for bending in a particular plane an I-section joist may be more efficient, if bending load can be applied in any plane, then the thin tube is to be preferred. It is for this reason that tubes are used as a strut or compression member in which failure could occur by elastic instability, or bowing. For torsion there is no better section, hence the tube is the typical main transmission shaft of an automobile. The stem of the bamboo plant is an excellent example of the properties of a hollow tube ...

I notice that many current bikes have flattened, non-tubular frame components. Why? Style? New materials? I would assume, knowing little about it, that the tube shape would generally retain its advantages regardless of the material. But perhaps the new material doesn't form tubes well?


I think the answer is aluminum. Note that I'm not an engineer, just a physicist. As I understand it, aluminum has different mechanical properties such as strength to weight ratio, and how it behaves when flexed. So it may require a different design approach to produce a strong but light frame. At the same time, it's easy to hydroform aluminum (blow it out into a mold using high pressure fluid), so you can in fact design a wider variety of shapes at a tolerable cost. And if you're going to engineer the shapes of the tubes, then why not make it look cool too.

I own one aluminum bike, relatively low end and not super lightweight... but it does look cool. ;-)


Aerodynamics an/or looking aerodynamic and/or distinguishing a brand by showing of what you can build.


Closely related (and even briefly shown in the video) to the description of a computer as a bicycle for the mind: https://www.youtube.com/watch?v=xqxWlvJ35yk


I don't really care for that metaphor, while it does make sense at a base level, I feel like it doesn't quite fit. A bicycle is (once constructed) entirely man powered - it only goes as well as we are able to power it.

The computer is more of a car for our minds - they run on electricity/gas, take minor low effort inputs from us, and transform them into massively larger outputs not due to simple mechanical laws, but because of a secondary source of impetus. There isn't that 1:1 input/output that a bike has.


Not only that, but a bicycle is something that feels like part of your own body when you're using it. If you think too hard about the positions of everything you'll probably ride worse. A computer on the other hand is something that requires careful thought to get the most out of it.

The real bicycle for the mind is pencil and paper.


That's a good analogy. Pencil (or pen) and paper go at human speed, like a bicycle, and have no artificial constraints (glyphs available for writing, for example).

I still use notebooks for some things. You can draw in a notebook (and yes, I know you can draw on a computer, but in many ways it is more involved). The link between thought and recording is much tighter than on a computer.

It would be interesting to look at how our tools shape and limit our thinking.


Also the interfaces for a bicycle have been functionally the same for over a hundred years. While they have changed with technology, a rider from 1900 could without issues ride a modern bike. I know a guy that uses a +70 year old bike daily, and it does the job he needs it for as good as any other bike. As a layperson it's possible to understand every mechanical part of your bike, and even fix them yourself with some effort.

To me bikes and computers are as different as they come.


> As a layperson it's possible to understand every mechanical part of your bike, and even fix them yourself with some effort.

That's part of the real joy for me - "hmm... something is making a noise" and then you can tinker until the noise goes away. There's learning feedback still available on a bike.


Does anyone know the source for this? I found a Scientific American article and an Amazon listing for an out-of-print book published by Scientific American (perhaps just a copy of the article).

https://www.scientificamerican.com/magazine/sa/1973/03-01/#a...

https://www.amazon.com/Bicycle-technology-S-S-Wilson/dp/B000...

EDIT: The URL includes 'Scientific American March 1973', which matches my first link. EDIT2: So I think that must be the source.


I don't know what you're looking for. Your own research has brought you to a page from which you can purchase a digital copy of the whole magazine for $8. What do you want, a printed copy?


Hub gears still seem like witchcraft.


Once you take one apart, it becomes more obvious. Best of luck getting it back together, however.


I've rebuilt old Sturmey Archer 3 speed gear hubs. It's not all that difficult. I've never tried ones with more gears, since 3 speeds are the sweet spot for my riding preferences and terrain.


No. That is reserved for sewing machine.


rohloff has a 14 speed hub


I've seen those on Amazon, but it seems like they just sell the hub and brake disc. Are you supposed to DIY the rest of the wheel or is the average bike shop able to build it for you?


In short: yes.

Slightly longer version: Find a good bike shop to do it for you. The wheels on a bicycle are about the only truly challenging thing to work on (short of suspension components or the headset bearings that are pressed into the frame), and about the only things that you can irretrievably screw up. A shop that builds more than a couple wheels a year will probably do a better job than the average bike shop.

If you're curious about what building a wheel involves, a good resource is The Bicycle Wheel, by Jobst Brandt [0]. Mind you he still that the bottom spokes of a wheel are in compression (which is demonstrably false; see Mavic's linear pull spokes, which literally cannot be in compression or the wheel would fall apart). Sheldon Brown's website is useful too.

[0]https://www.amazon.com/Bicycle-Wheel-3rd-Jobst-Brandt/dp/096...


> Mind you he still that the bottom spokes of a wheel are in compression

I think you might want to read pages 7–8 again: "Wires must be tensioned to prevent their buckling under load. With tension, wires can support compression loads up to the point where they become slack. The same loads that increase compression in wooden spokes, reduce tension in wires. As in algebra, where negative and positive numbers are combined to give algebraic sums, in spokes tension and compression are the negative and positive forces whose sums depends on built-in spoke tension and the carried load."

So the bottom spokes can support a compressive load because this is smaller than their unloaded tension.


Yeah, I should have anticipated stirring up a debate with somebody who has read the book more recently than 10 years ago. I should have avoided mentioning it; the book as a whole contains a great deal of practical information.

Anyhow, I think we are fundamentally in agreement that all of the spokes in the wheel are in tension at all times. I am not an engineer, but I did run this bit by an engineer. He was in agreement that the fact that the bottom spokes are under less tension does not mean they are supporting the load via compression.

At best, the passage is a bit misleading; none of the spokes on a bicycle wheel are ever in compression (or as Brandt rightly claims, they would buckle). Claiming that the reduced tension (again, correct) supports a "compression load" is misleading.

Sorry I can't stick around for further discussion; I'll check back later.


Mind you he still that the bottom spokes of a wheel are in compression

In Brandt's defense, the last edition came out 25 years ago, and as I recall the tension/compression debate wasn't settled yet.


Any average bike shop should be able to build a wheel from a hub, but you'll certainly also need the controller bits that allow you to actually switch the gear. Some OEM kits don't have those parts. You should probably also ask your favorite bike shop if they feel comfortable doing maintenance work on this piece (or ask yourself if you do).

I'd keep in mind that the rohloff speed hub is an amazing piece of technology, so it comes with a hefty price sticker. I'd question it's really worth it for the average bicycle person when a shimano alfine 11 gear hub costs barely a quarter.


I’ve been wanting a Rohloff build for years but feel I don’t have a trip planned to justify it. One day...


Which costs as much as a whole new regular bike...

Still an awesome bit of kit.


The bicycle was, arguably, a bit too late. Imagine how cities would be constructed today if bicycles (with modern functionality and affordability) had predated cars by 50 years.

Imagine people trading in their horses for bicycles, for much easier care, less pollution, much smaller and flexible (it seems to me) alternatives. Imagine the variety of bikes people would come up with, lacking alternatives: Personal transport, of course, but also cargo, long-haul, rough terrain, tandem/triple/etc when more power is needed, rickshaws, etc.; with bikes already being the established 'first mover', would we use cars for as many purposes as we do today? Imagine how cities would be constructed, providing for bikes first, with the car fitting in later - from roads to locations of retail and transit.

For some things you still may have needed horses, such as pulling heavy loads. Also, I wonder if the terrain and roads would have suited bicycles (cobblestones and muddy roads probably aren't so great to ride on) and, if not, if people would have invested in the infrastructure; beware the modern myopic perspective about cities - back then almost everyone lived in rural areas. Finally, in some less economically developed parts of the world bicycles did become immensely popular before cars, IIRC; I wonder how these issues played out there.


> Imagine the variety of bikes people would come up with, lacking alternatives: Personal transport, of course, but also cargo, long-haul, rough terrain, tandem/triple/etc when more power is needed, rickshaws, etc.; with bikes already being the established 'first mover',

This did happen: Bicycles used to be the primary mode of transport for many many people even in Europe. It certainly was in China and other parts of Asia. Long John Style Cargo bikes - the type that Bullit for example builds - were conceived in the early 1920ies. Butchers/Barkes Bicycles were common until the 1950ies in Europe. Cars were a luxury back then, common people used bicycles, walked or used public transport.

I think that electric assistance is what will drive a renaissance of cycling as a mode of transport if infrastructure can be provided that makes cycling in cities safe and enjoyable. It allows sufficiently high speeds to achieve reasonable transport times even on medium distances for most people.


Imagine people trading in their horses for bicycles, for much easier care, less pollution, much smaller and flexible (it seems to me) alternatives.

You've just copy-and-pasted Columbia's ad text from the late 1800s. The problem was not that bicycles were too late, but that bicycles were out of reach for the common working man for quite a while. Multi-speed, shaft-drive bicycles with pneumatic tires were available in the 1890s. They were also priced like Teslas.

Source: have been a member of the U. S. counterpart to the Veterans Bicycle Club (where this article came from) since I was a kid.


>The problem was not that bicycles were too late, but that bicycles were out of reach for the common working man for quite a while.

What's the difference?


There were tons of bicycle manufacturers, so the bicycle wasn't "late", there were plenty of them. The difference is that they were luxury items.

"The problem with the airplane was that it was late..." No, we've had airplanes since 1903. The problem is that I can't afford, even as an upper middle class software engineer, to keep one in the air.


Thanks.

> have been a member of the U. S. counterpart to the Veterans Bicycle Club

What is the club? An historical society? Whence the name?


The Wheelmen: http://www.thewheelmen.org

(Not to be confused with the League of American Wheelmen, the old name of what is now the League of American Bicyclists.)




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