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Transcript of Gear Heads
for the wealthy (cost and practicality);
looked down on by other groups as
"Dandy horses" Pre-19th Century Idea of Human-Powered Vehicle Technology Manufacturing Materials Democratic/Utilitarian Ideals Cast and Wrought Irons, each about 8 g/cm^3 were common industrial metals;
cast iron had the properties:
Tensile Strength: ~124-276 MPa (depending on treatment)
% Elongation: Negligible due to brittleness (yield strength is also unlisted in the Callister book)
Wrought Iron had the properties:
Tensile Strength: 414-872 MPa
Yield Strength: 276-621 Mpa
% Elongation: 2-18 (inversely related to strength)
Steel (iron with carbon interstitials) was very expensive at the time, and had the approximate properties (depending on treatment):
Tensile Strength: 400-590 MPa
Yield Strength: 220-490 MPa
% Elongation: 12-23 1817 Velocipedes Promoted/displayed in races and rides in general
-initially attracted a lot of attention 1771: Canon Bore 1825 H.C. Oersted isolates aluminum
Separates in a reaction between alum and a potassium-mercury mixture
In later analysis of his isolation process may have actually been an aluminum-mercury alloy 1808 Sir Humphrey Davey proposes the existence of "Alumium," a new metal present in alum, long used as an astringent, and unsuccessfully tries to isolate it with electrolysis. -Inspired scientific curiosity Aluminum's Properties Identified 1867 Pedal-Powered Bicycles (~1840s onward) solution to velocipede problems
Were more practical than velocipedes but still had problems with cost and practicality.
Producers experimented with cast frames
Speed: racing was common, often on indoor rinks
Comfort-'Boneshaker" nickname referred to experience of riding on contemporary roads 1970s Bikes begin to enter American popular culture again; On Any Sunday, a 1974 Motocross documentary, popularizes the idea of BMX, with official events takign place within a few years, while Breaking Away uses road racing as a plot structure for a coming-of-age film; notably, it associates racing extensively with Italian culture Design/culture pressures:
-more comfortable/practical Solutions included:
-Three- and four-wheeled designs
-others 1845 -More of of fad
-Imported from Germany to the US, France, the UK, and elsewhere
-Eventually laws passed against their use in towns 1870s "Bike Craze"
-Bikes become increasingly popular,
with the audience expanding beyond the
previous range of wealthy hobbyists
-Regulations against bikes were common in many areas; the US was in general was notably opposed Cycling Clubs
With biking becoming more popular, existing biking groups often grew and combined into larger groups, with some notable examples being the League of American Wheelmen and the Union Cycliste Internationale. These let bikers have a wider community and let them organize to campaign for legal acceptance (at least is the US, it wasn't unheard of for bicyclists to be arrested or fined with little provocation) and benefits like better roads. With the desire for speed as a pressure,
bikes began to take on what is now called
the 'penny farthing' profile in order to maximize
the distance traveled per rotation. Manufacturing Diversification:
As bicycles became a more profitable business, a wider range of industries, including sewing machine and gun producers, began to incorporate bicycles and other vehicles into their production lines, which enabled new technologies to be introduced Bike popularity led to, or grew alongside, a thriving alternative market for human-powered vehicles For many, tricycles represented a more respectable and elegant form of the technology, being suitable for women and the elderly; other alternative for bikes included impractical "Side-saddle" bikes operated while standing.
This market also tended to absorb early safety designs, which were seen as beginners' products Thanks to the dangers inherent in bike design (falls,
continually rotating pedals, etc.), bikes came to be seen as mostly the domain of athletic younger men, and were seen in this light by their proponents as well; what are seen in retrospect as advances were often then often seen as unnecessary or weak. A cultural aesthetic also grew around high wheeled bikes. 1890s The unsafe aspects of bikes began to be seen as problems to be solved, rather than features of the technology, leading to an explosion of safety-oriented redesigns, which often worked off the assumption of inevitable falls First Chain Driven Bikes:
These grew in popularity out of the safety market; advances in machining also were a factor. This was the first use of sprockets, which were likely machined from stock sheets of metal. Early chain bikes struggled due to cultural aesthetics. Gear ratios were used to capture the feel of "Ordinary" bikes as tires shrunk. -Predecessor of milling machine; designed to
meet new needs for scale of production and
precision in canons, steam stacks, etc. -Casting
-Rolling (1718 onward)
-Hand-working 1818 Eli Whitney invented
a milling machine, which
could work on an xyz axis Made bikes more complicated and reintroduced some issues with vibration, etc. Pneumatic tires: These improved the comfort of riding bikes and earned the respect of "serious" bikers, together with safety designs, when the combination made for record-setting times in races Association with Women's Rights movement
-Bikes allowed women to be more autonomous in transportation
-Changed clothing to more practical fashions
-Idea of women using standard bicycles began to be seen as less of a scandal
-Susan B. Anthony:"I think [the bicycle] has done more to emancipate women than anything else in the world. It gives a woman a feeling of freedom and self-reliance." (1896) 1900s Duralumin, one of the earliest aluminum alloys, is invented; it contains about 4% copper, which improves hardness and strength. New heat treatment methods for aluminum improved the performance of this and other alloys as well.
Modern equivalents (2000 series Aluminum) have:
% Elongation: ~20
Tensile Strength: ~500 Mpa
Yield Strength: ~350 MPa Aluminum begin to be used in bicycles, coinciding with further improvements in aluminum manufacture by Karl Bayer, who discovered how to refine aluminum oxide from Bauxite, a common mineral. With prices at 20% of their 1850's levels, aluminum was practical to use in a variety of applications, including aviation, automobiles, early electric wiring, and bikes, although its relatively low strength led to special considerations in their construction. -Cheaper, more practical bikes lead to military applicaitons (transport, communication)
-In 1897, the US Army carried out a test using the 25th infantry, which covered about 1900 miles from Missoula Montana to St. Louis.
-Biking Prominent in WWI, WWII, in at least nominal use until 1990s.
-Often seen as start of mountain biking 1897 1890s Punch Cartoon. Wikipedia. 2013 1854 Henri Sainte-Claire Deville, a French chemist, refines production using cheaper sodium as a reactant.
more economical to produce significant amounts of aluminum
At the time however, it is more expensive than gold. 1866 The Hall-Héroult (its modern name)
Simultaneously discovered in Ohio and Gentilly, France.
Uses electrolysis to isolate aluminum dissolved in Na3AlF6
As electricity facilities became more common, the process became more economical.
Currently, producing a pound of raw aluminum uses 14,000 KWH, while a recycled pound uses 700. 1885
The "Rover," often cited as one of the most successful safety bicycle, is introduced alongside similar models to a mixed reception. This design soon becomes a standard for further developments. https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&docid=SiOq7xn6x8o__M&tbnid=yb0m9QvHWIu9BM:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.pedalinghistory.com%2FPHhistory.html&ei=fZtdUaKGO4fU2QXzmYCACg&bvm=bv.44770516,d.b2I&psig=AFQjCNFzCnjuGw0UrdwiaS9MiQLLnyJNFg&ust=1365175546428834 The first specific use of gears in bikes actually predated chain-driven models; hub gears located in the hub were used for variable speeds on tricycles and chainless bikes. This scheme is still used in some cruisers and similar bikes. 1880s Culturally, aluminum caught the public imagination, being among new elusively man made materials such as plastics and processed woods that were developed over the end of the 19th century. Authors including Charles Dickens and Jules Verne enthused about its potential; for instance Verne had the titular rocket in "Rocket to the Moon" made of aluminum. Illustration from "From the Earth to the Moon." Wikipedia. 1872 1948 Bicycle Thieves (Ladri di Biciclette in Italian), is released; the plot venters around a working man whose job depends on having a bicycle, and it shows both the cultural and the emotional This 1960s British ad for bicycles lays out a pragmatic case for bicycles on their merits over public transportation or driving; it differs from contemporary US views in this respect. 1974 2010s Portlandia bicycle clip, 2011
This clip shows a tongue-in-cheek portrayal of a fixie rider; this portrayal pokes fun at some of the worse associations with habitual bike riders, including activism about bikes as a borderline moral issue, pushiness in traffic, and the association with hipsters. 2000s 1990s This 1990s Canadian commercial similarly draws on a sense of nostalgia for bikes; culturally, the connotations are somewhere between America and Britain, 1980s In the 1980s, bikes continued to remain popular in American and global culture, with BMX and mountain biking becoming more accepted Premium Rush, a 2012 action movie centering
on bicycle couriers in New York, is somewhat unusual
in that is focuses on adult bike riders 1910s 1920s 1930s 1940s 1950s 1960s In 1952, John Parsons, a professor at MIT, combines computer technology and milling technology to create the first CNC (Computer Numeric Control) milling machine; this is now the standard means of sprocket production at virtually all levels of the industry. Bike Scene in ET-The iconic bike chase in ET was more typical of American perceptions of bikes even during the new "bike boom" in that they are associated with children and a sense of nostalgia. Lance Armstrong
In this now somewhat ironic ad, Lance Armstrong
defends himself against accusations of steroid use; Armstrong stands out in recent American bike culture as being a breakout cultural figure in an often less-represented field. Breaking Away, a 1979 film, featured a suburban American teenager who becomes fascinated with cycling, focusing more on road bikes -As cars became more practical, they displaced bikes in the US and elsewhere as the transportation of choice; ironically they drew on biking technologies and roads campaigned for by biking groups
-Bikes became the domain of hobbyists and children in the views of most Americans
-The US' view of bikes has in some ways never returned to the 1890s utilitarian view
-However, in the UK, France, notably the Netherlands, and elsewhere, bikes continue to occupy more of a pragmatic place culturally.
-In some contexts, bikes are more practical for cars; for instance, in Malawi, bikes were introduced in almost direct competition with cars, and are widely used for economic and infrastructure-related reasons. The Bessemer Process-revolutionizing the steel industry
produces steel from pig iron,
more economical to produce
thus an increase in the range and volume of applicators By the 1940s, racers and touring bikers in Europe has started to use ten-speed bikes (two gears on the pedal and five in back) for greater flexibility on levels of slope as well as levels of rider effort. These took several decades to spread to a more causal market, but soon became a standard for road and mountain bikes -1960s-1980s: Revival in US Bike Industry
-1960s Fitness trends encourage bikes as exercise
-1970s Also embraced under environmental movement
-Bikes as political expression Machine was hand-cranked and directed
required a skilled operator
Flexibility and standardization increased
Aluminum 7068, considered one of the best aluminum alloys, became available in 2000; modern bikes typically use alloys 6061 and 7075. 7068 is advertised as the structural equivalent of steel, with a tensile strength of about 710 MPa and a yield strength of about 680 MPa. Stronglight became the first successful manufacturer of aluminum cranks (referring to the pedals and sprockets as a unit) in 1933 In 1910, Paul de Vive, a touring enthusiast and prominent figure in the French biking community, invents a new kind of derailleur (distinct from British-style internal hubs) to enable bikers to change between gearing ratios. Although it is practical, it is derided by many contemporary cyclists as a luxury for weaklings. Paul de Vive, Jim Langley, 2011 http://upload.wikimedia.org/wikipedia/commons/4/44/Bicycling-ca1887-bigwheelers.jpg The 1930s saw dramatic advances in the aluminum industry; improved manufacturing methods allowed better uniformity and reliability of cast and worked parts, and some of the most influential alloys, including 7075 and 6061 (the alloys we tested) were developed in the mid-30s.
These alloys introduced Chromium, Magnesium, Zinc, and other elements into the alloys; together with new heat treating techniques, this allowed aluminum to reach tensile strengths nearing 600 MPa, putting it in the range of weaker wrought irons and steels. Duralumin found applications in many fields, with a notable early use being the construction of airships; during World War I, the Germans produced 726 tons over one year for this purpose In 1958, Campagnolo introduces the Gran Sport derailleur, which improved on earlier models
-Riders previously needed to adjust chain position with levlers on the frame
In 1961, SunTour, a Japanese company, introduced slant parallelogram derailleurs, the most common model now 1983: Aluminum moved to a new level in consumer bikes; Canondale, a bike manufacturer, started an "aluminum for the masses" campaign aimed at popularizing its usage.
By this point, there are also purpose-built mountain bikes by manufacturers like Specialized (Japanese) at affordable prices BMX Raisin Bran commercial capitalizing on the idea of
it as a "cool" activity for teenagers Bikes feature in this chase scene in the 1983 Jackie Chan movie "Project A" in a somewhat ambiguous cultural context. 1982 Specialized Stumpjumper-Mombat.com (2011) Both of our artifacts, aluminum alloy sprockets, were likely produced during the 1990s; one is made of 6061 Aluminum, while one is produced 7075 Aluminum. The fist anodizing process is patented in 1923; this is to address the fast corrosion of aluminum alloys; earlier solutions had included a pure aluminum coating.
-Anodizing is an electrolytic process where current is passed through a metal salt solution By now, organized biking groups tend to break down along either clubs in the tradition of earlier racing clubs, which tend to include the most competent riders, or political groups often working from environmental or social agendas. Canon Bore Lathe, BBC, 2013 Sir Humphrey Davey, BBC, 2013 Velocipedes, A History Of Bicycles by Serena Beeley, 1992 Milling Machine, Wikipedia, 2013 Aluminum, Wikipedia, 2013 Friedrich Wöhler, a German chemist, produces enough aluminum to evaluate its properties, including unprecedented lightness and relative strength, which excites interest and further funding.
Properties of pure annealed aluminum:
Density: ~2.7 g/cm^3 (as compared to 7-8 for irons and steels)
Yield Strength: ~70 MPa
Tensile Strength: ~140 MPa Duralumin, Wikipedia, 2013 "On Any Sunday Open." YouTube. 2011 -Unique influence; both progressive and conservative in design
-Recumbent bikes (invented 1910s) banned in the 1930s
-Accepting Derailleurs triggered rapid innovation, trickling into wider market
Tullio Campagnolo, a champion racer, is one of the most prolific bike inventors of the 20th century, with inventions including quick-release wheels (1930s) and improved deraileurs (1958), among others. Breaking Away ad, Youtube, 1979 "Project A" YouTube. 1983 ET Clip. YouTube. 1982 BMX Commercial, YouTube, 1980s Production steps:
-Rolling into sheets
-Annealing (Recrystallization)-413°C for both, differences in subsequent heating and cooling
-Milling/Cutting into Sprockets
-Stamping, grinding, into final shape
-Anodizing-Electrolysis; hard, abrasion-resistant finish Canadian Bike Ad. YouTube. 1990s Lance Armstrong-"I'm on my Bike. What are you on?" ad. YoutTube. 2011 Portlandia bicycle clip. YouTube. 2011 Premium Rush Ad. YouTube. 2012 Peak of popularity in US:
-With new bikes becoming affordable and durable bikes from the 1870s bike craze being even cheaper, bikes were finally available to society at large
-Seen as the cultural peak of bike use; they saw use everywhere from the army to urban and rural transportation to recreation and racing
-No real competitor for personal transportation -1960s-1980s: Cheap, high-quality Japanese 10-Speeds and Mountain bikes make them more economical
-First time in US in decades that adults make up a significant number of buyers. "Big Wheels." Wikipedia. 2013 [Contemproary illustration] Hub Gear. Sheldon Brown.com 2012. WWI Italian Bicycle Infantry. Wikipedia. 2013 25th Bicycle Corps . Bicycle Corps.Blogspot. 2010 WWI Italian Bicycle Infantry. Wikipedia. 2013 Parsons' CNC Machine. Pennsylvania State University. 1952 “See How We Made Our Sprockets.” YouTube. 2011 Nishiki International. Wikipedia. 1977 http://www.tubechop.com/watch/1080748
http://www.tubechop.com/watch/1080760 Excerpts from The Drama of Steel. YouTube. 1946 Hub Gear. Sheldon Brown.com 2012. Aluminum Bike ad. 100 Years of Bicycle Posters by Jack Rennert. 1890s Rover Bicycle. About.com. 1885 Bicycle Fall. Pedaling History. 1880s League of American Wheelmen logo. Wikipedia. 2013. Birmingham Small Arms Company Advertisement. Grace Notes. 1890 Tullio Campagnolo. campyonly.com. 1940s Campagnolo Derailleurs. Italian Cycling Journal Blogspot. 2011 (1958 onward) Rocket Alloy Chainring 94mm 5 Bolt 48T Silver. Amazon. 2013 As Presented by Gear Heads The Bicycle (Sprocket)