Valves


Bicycle valves
from BikeWebSite.com

The two common types of valves used on bicycle inner tubes are Schraeder and Presta.

Schraeder valves work just like the ones on a car. You can depress a center pin to release air. The pin is depressed by an inflator nozzle when you add air.

With a special small forked tool, called a valve core tool or valve core remover, the entire Schraeder valve can be removed from the inner tube and replaced. There are long and short versions, and are entirely interchaneable with automotive valves.


Valve Core Tool

Valve core tool with short Schraeder valve cores
Available from Grainger

Presta valves are a bit lighter, and smaller in diameter. Some bicycle rims are too narrow to accommodate Schraeder valves. Presta valves are as fragile as they look. To add or remove air, you must first loosen a small nut at the tip. This is non-removable. You only loosen it enough to allow the inner pin of the valve to move up and down. Then you can press the pin to remove air, or use an inflator to add air. Unlike Schraeder valves, the pin is not spring-loaded. It depends on air pressure to keep the valve closed. To augment air pressure locking the valve, the nut can be secured.

People have often broken these nuts off. The good news is that the valves tend to work OK without a nut.

A third type of valve, the Woods valve, also known as Dunlop valve, is rarely found on older bikes in Japan, and European and some third-world countries. This is the same diameter as a Schraeder valve, usually has a removable core, and can be filled with a Presta valve inflator.


Woods Valve
Woods or Dunlop valve
Photo by SCEhardt

Most valves have optional valve caps. The purpose is to keep dirt out of the valve for proper functionality. Even without the caps, most valves provide many years of reliable service.

Do you have a slow leak? Most slow leaks are punctures in the inner tube, but some are due to a leaky valve. With a Schraeder or Woods valve, you can put some water or saliva on a fingertip, hold it lightly over the top of the valve, and look for bubbles. With a Presta valve, you can use a similar technique, using a cloth and some soapy water. Leaky Schraeder valves are often just loose. Just give them a twist with a valve core tool, and you’re all set.

Standards

In the past, bicycle mechanics had to be aware of standards. This is less common with modern bikes because most are made in Asia, and they all conform more-or-less to British Standard component dimensions.

The standards that were common in a previous era were British, French, Italian, and Schwinn.

A very uncommon standard was Whitworth, also known as “British Standard Five,” “BSW” and “BS5,” found only on old bikes made in the British Empire. Whitworth is based on fifths of an inch. Not only are the threadings non-interchanheable, most wrench sizes are different as well.

The old-time mechanics, and people today working with vintage bikes, have to be careful about threading. For instance, you can screw a French freewheel onto an English hub, and although a bit stiff going on, all will seem well, until you ride the bike up a hill. The threads will strip, irrevocably damaging the hub.

Whereas the English standard used inch-based sizing, the French mostly used metric-based. To confuse matters, some French components used inch sizes. For instance, many French bikes were made with 27-inch tires.

Italians also used mostly metric but some inch sizing as well. The Italian threading, as well as Whitworth, used a 55-degree thread pitch angle, which can be problematic when things appear to match, but result in weak engagement.

Schwinn used to be in a world of its own. Whereas many of the English standard threaded parts used 24 threads per inch, Schwinn preferred 26 threads per inch. This caused no end of troubles for home mechanics as they would try to screw Schwinn axle nuts onto Huffy or Murray axles, resulting in badly damaged threading. The common theory is that Schwinn wanted to lock up the market for “Schwinn Approved” replacement parts. Schwinn also used a different tire sizing, sometimes interchangeable with EA1. Most tires were made to the EA3 standard, which although nominally the same, didn’t interchange at all. For instance, a typical tire size of 26 x 1.75 would not fit a Schwinn 26 x 1-3/4 wheel.

See also: Metric and Inch.

The Difference Between a Screw and a Bolt

Whether a fastener is a screw or a bolt is not determined by its head. Some people think that anything you turn with a screwdriver is a screw, and anything you turn with a wrench is a bolt. Not true. A bolt fastens into something that’s threaded, such as a nut, or a pre-threaded component. A screw makes its own threads, such as into sheet metal or wood. Whether a fastener is a screw or a bolt is not determined by its head.

bolt

Metric and Inch

Two sizing systems are in common use among bicycles: Metric and Inch. Metric sizes are more common, with inch being found mostly on American-made bikes. However, there are some legacy sizes that have remained in modern bikes, especially those manufactured in Asia: Some of the larger threaded components are still measured in inches, such as bottom bracket and fork steering tube threading, and pedal threads. The metric system is based on millimeters. There are exactly 25.4 millimeters in an inch. Ten millimeters is also known as a centimeter, and a hundred centimeters is a meter. To take that to the extreme, 1000 meters is a kilometer, which is around six-tenths of a mile. For those of you in countries outside the USA, an inch is 25.4 millimeters. There are 12 inches in a foot, and 3 feet in a yard. 1760 yards make a mile, which is approximately 1.6 kilometers.

Getting back to nuts and bolts, inch-based sizing is controlled by the Society of Automotive Engineers, and sometimes inch-based sizing is referred to as “SAE.” That organization sets the standards for machine parts, such as thread per inch on nuts and bolts, head sizes, and thread pitch angle (60 degrees).

Metric nuts and bolts also use 60 degree angles, except for the Italian standard, which is 55 degrees.

55 degrees was also used in an old British standard called “Whitworth” or “British Standard Five,” also known as “BSW” and “BS5.” Most Whitworth wrench sizes are not interchangeable with SAE. In Whitworth, nuts and bolt heads are 5/3 of the major diameter of the bolt. You’ll only find Whitworth nuts and bolts on old bicycles made in the United Kingdom.

See also: Standards

Bicycle Technology Picture Book


A Coffee Table eBook


Copyright 2014-2021, Jeff Napier





Start Here


Table of Contents

A bicycle is the most efficient machine in terms of energy expended for moving weight over distance.


A human on a bicycle is also the most efficient animal on earth in terms of energy spent for travel.


According to at least one statistical study, the health benefits of cycling outweigh the risks by twenty to one.


Therefore, taking a closer look at these wonderful machines will be fun, don’t you think?


This book was built for your enjoyment. It is a coffee table ebook containing pictures of all sorts of bicycles and related equipment from the very first bikes, to prototypes so modern they can’t yet be built. Most of the pictures illustrate mechanical engineering at its finest. I have inserted brief explanations and commentary where I thought it might be useful.


Don’t forget to check out the Art Bikes
chapter!


Enjoy! – Jeff
Napier
, author


History


Table of Contents

When people first figured out that you could attach pedals to bicycle wheels, they discovered that the bikes didn’t go very fast. But, if they could make the wheels bigger, they could go faster. This was the world’s first version of "gearing up."


The limitation was the length of the rider’s legs. Pretty soon, it became ordinary for bicycles to have large front wheels, ranging from 50 to 64 inches (127 to 162 cm) in diameter. So, these became known as "ordinary," bikes, commonly referred to as "ordinaries," or "ordinary racers." They were also called "Penny-Farthings" named after large and small coins of the era, and sometimes "boneshakers" because they had solid rubber tires, and no shocks, while the bumpy streets were typically unpaved or made from bricks.


It was still years into the future before veterinarian and inventor John Boyd Dunlop would create the first air-filled tires for his son’s tricycle.



A rider on a penny-farthing replica
image by Agnieszka Kwiecień, license: CC-BY 3.0

Penny-farthings weren’t the first bikes. The first is credited to a German inventor, Karl Drais. He built the first one in 1818, and called it the Laufmaschine. It wasn’t long before his simple contraption was copied throughout Europe and the United States. The English started calling them dandy-horses. In America, they were hobby-horses. and the French called them draisiennes or draisines. It wasn’t until 40 years later than someone in France figured out to attach pedals to the front wheel, so riders didn’t have to kick along the sidewalk to go places. This new French version was called velocipede (literally: "speed foot"), although that term has come to mean any of a wide variety of early bicycles.



draisine




Whippet "Safety"
image by Ian.wilkes


Penny-farthings with their outlandish proportions replaced draisines to gain speed. Bikes were safer dimensions but still capable of great speed were soon invented, and they became commonly known as "safeties." The picture above is an oddly over-engineered model.



McCammon "Safety"
image by Ian.wilkes


This one uses an ingenious seat height adjustment that might be a nice modern re-invention.



Fred Birchmore


In 1934, Fred Birchmore, of Athens, Georgia, who was 22 years old at the time, took a 40,000 mile (64,000 kilometer) mile trip. 15,000 of the miles were water crossings, but the remaining 25,000 miles (40,000 kilometers) were by bicycle, as he circumnavigated the globe.



A bike from 1865




Classic English bike with rod brakes
image by Pramod
Kumar T.K.




Bike repair in Africa, early 1930s




Shaft drive bikes have been around almost as long as chain drives

image by Ian.wilkes


Shaft drive bikes eliminate the need for pants clips, and you won’t get greasy. Changing the gear ratio requires parts that are not usually available.



An early form of gearing. Pressure on pedals unwinds straps around racheted drums.
Nicola




A restored Shelby from 1938
Aaronwiegand




Military use of bicycles


The caption on this picture says, "US 25th Infantry on bicycles. Caption: "On June 14, 1897, Lieutenant James Moss,
U.S. Army, led his bicycle corps of the 25th Infantry, from Fort Missoula, Montana, up wagon trail and Indian path, to St. Louis, Missouri, arriving July 16, 1897."


from highonadventure.com/Hoa97aug/Montana/montana.htm.






Swiss army bike
Joe
Mabel




Tieum512




Side-by-side tandem
State
Library of New South Wales


Unicycles


Table of Contents

You would think that the idea of pedals and cracks attached directly to a wheel would have died out with penny-farthings. But no, there are still vehicles with direct drive wheels. These would be unicycles.



Unicycles come in a variety of shapes and sizes. Some are for off-road competition, a somewhat dangerous skill that is quite difficult to master. These typically have large diameter wheels with fat, knobby tires.



Off-road unicycling
image by Samuel
Mann


Others have thin
large diameter wheels for city commuting.



A commuting unicycle
image by Midiman



Other unicycles have small wheels, sometimes for children, and sometimes for performance, since with a smaller wheel, you can maneuver more precisely at slower speeds, and on a smaller stage.



image by xeaza


Another category
is tall unicycles, often called "giraffe" unicycles. Using
a chain drive from the pedals to the wheel, they can range from 4-1/2
feet to over 100 feet (1.4 to 30 meters) tall.



image by Russavia


Sem Abrahams holds the world record with a unicycle more than ten times taller. His unicycle was just a bit over 114 feet (34 meters) tall. The picture below links to a video of Sem’s world record ride. If your ebook reader doesn’t support Internet links, you can go to http://www.semcycle.biz/record/html/35m.html.




World’s tallest unicycle


Then there are monocycles. Whereas a unicyclist sits above the wheel, or outside of the wheel, the monocyclist sits within the wheel.



Monocycle


What do you suppose will happen if this rider has to stop fast?
Right! One of the problems with monocycles is when you put on the
brakes, you tumble right around with the wheel.


You would think that you can’t remove much else from a unicycle, and still have a human-powered vehicle. But actually, you can remove the seat, frame and bearings. Then you have what’s called an "ultimate wheel."



image by Ian
Muttoo


When first learning, you can cover the sides of the tire with electrical tape. This way, you can use the insides of your shins as a frame and bearings. Just squeeze your leg close together, and let the wheel rub as needed. In time, you can learn to ride without contacting the tire at all. At first however, you’ll want to wear pants, at least, since the wheel will inevitably tilt one way or the other and rub uncomfortably hard.


Circus Bikes


Table of Contents

Amazing tricks can be performed on a BMX bike.



Freestyle BMX bike
image by Tukka


In the above picture, notice the footpegs on the front and rear axles. Also notice the rotor, a device mounted on the handlebar stem so that the handlebar can be turned all the way around without interference from the brake cables. This bike also has a long frame to accommodate turning the front wheel around without interference from the rider’s feet or knees.


Even moreremarkable tricks can be performed on a circus bike.




Circus Bike



image by
Vintageedept



image by Shizhao



image by Shizhao


Plastic
Bikes


Table of Contents

The idea of making bicycles almost entirely from plastic has enticed people for years. In 1971, Original Plastic Bike Incorporated was founded based on a design for a complete road bike that was supposed to weigh just 17 pounds (7.5 kg), and be as strong as, or even stronger than steel and aluminum alloy bikes. Some prototypes were built, but the bike never went into production.


Itera Plastic Bike


We are no longer surprised to see plastic bicycle wheels in the smaller diameters. These wheels aren’t quite all-plastic. The hubs are made from regular steel components.



image by Incase


Recumbents


Table of Contents

Recumbence: The act of laying down.


Recumbent bikes, sometimes called "bents," seem like a relatively new invention. Here’s a picture of a recumbent from 1914:





Trans-V recumbent




Toxy CL recumbent
image by EvaK




Cruzbike Vendetta
image by Bentrider811








Android front wheel drive recumbent
image by
http://commons.wikimedia.org/wiki/File:Android_FWD_recumbent_4.jpg




Velokraft No-com




image by bradhoc




Tandem recumbent
image by BetacommandBot


Recumbent tricycles answer to the slow speed stability problem from which many recumbents suffer, and to starting and stopping nicely, but have design issues. With two front wheels, they tend to catch a lot more wind, which defeats one of the primary advantages of recumbents. With two rear wheels, traction can sometimes be a problem, and transmitting power to one or both wheels requires a more elaborate drivetrain.



Recumbent Tricycle
image by Boliston


Tricycles
and Quadracycles


Table of Contents



Rickshaw
image by Joost J. Bakker from IJmuiden


Rickshaws are almost always designed with one wheel in the front, and two in the back to support the weight of passengers. You’d think rickshaws were invented somewhere in Asia, but they are an American invention.



Rickshaw
image by Les
Chatfield


Quadracycles can be unique and fun, but don’t add anything in terms of efficiency. They may be safer, since they are hard to fall off. (Your author has discovered it is not impossible to fall off a quadracycle!)


Quadracycles are often used when a group of three or more people want to go together on a human-powered machine.



Antique quadracycle
image by Randal J. (RJFerret)




Quadracycle
image by Prayitno


Tricycles and quadracycles are often created for people who have disabilities, such as paralyzed legs, since balancing a two-wheeled machine would be difficult.


Human-Powered Cars and Boats


Table of Contents

Through the years, inventors have tried to add car-like features to bicycles, with varying degrees of success. The problem quickly becomes one of weight versus convenience. Putting doors, a roof, and comfortable seats in a human-powered vehicle raises the weight so it is hard to take it up hills. Maintenance can also be an issue. Until someone makes a standardized one that is very popular, replacement parts will not be readily available.


Finally, if you enclose a rider, you need to do something to keep that rider cool in warm weather.


One machine that was popular in the mid 1970s was the PPV (People-Powered Vehicle). This semi-enclosed vehicle could accommodate two riders, or one rider with several bags of groceries. With one rider, it was a monster taking it up hills, even with its three-speed transmission. To the inventor’s credit, for durability, it used a real transmission instead of a three-speed Sturmey-Archer, Shimano or Sachs hub. On the other hand, for stopping, it depended entirely on a drum brake in the front wheel, controlled by a single brake handlever and cable.



PPV
image by livewombat


Pedal-powered boats are terribly inefficient, but they’re fun! You can rent these at many resorts, parks, marinas and so on, and they are calm, meditative fun.



Pedalboat
image by Bart Everson


Electric
Bikes


Table of Contents



image by Pleclown


The idea of hooking up a battery and motor to a bicycle is attractive. Imagine that you are a healthy commuter who has an off day. Wouldn’t it be great to let the bike to all, or most of the work? Or, perhaps you’re not so healthy. You can work your way slowly to better health by letting an electric bike do most of the work at first, and less and less as you regain your health.


The line between what can be called an ‘electric bike’ and other two-wheeled electric-powered machines is blurry.


Electric motorcycles are being manufactured that weigh hundreds of pounds and have great speed and range.


Electric scooters of all sorts ranging from toys to machines ridden by professional security, maintenance and guide personnel, such as the Segway, might be called electric bicycles by some.




Segway


Conversion kits can be attached to most adult bikes, so the mountain or road bike you’ve always enjoyed can continue to entertain you, but now as an electric bike. However, conversion kits can be somewhat clunky compared to bikes designed and manufactured to be electric bikes in the first place.


Hundreds or thousands of people have tried their own homemade conversions.



A homemade electric bike conversion
image by Hamish
Darby


The unwieldy-looking bicycle pictured above used an ordinary car battery mounted above the front wheel. These batteries have poor range to weight ratio. Being filled with liquid and lead, they are remarkably heavy. The inventor of this bike reports having crashed into a tree and smashed his battery shortly after the picture was taken.


Electric bicycles are manufactured with and without pedals and human-powered drivelines. Perhaps without pedals, it can’t be called a ‘bicycle.’ I’ll leave you to decide.




Art
Bikes


Table of Contents

Bicycles are good candidates for artistic treatment, as the
following pictures illustrate.









image by Chris
Gilmore




image by Donna
B McNicol




image by hAdamksy




image by Amit Patel




image by Porsche
Brosseau





The Orange Krate, one of a series of art bikes, all in the same configuration, but with varying colors, manufactured by Schwinn in the late 1960s.
image by Nels P Olsen




image by Andy
Mitchel


Artistic Unicycles


Then we have art unicycles. Unicycles have been decorated, outfitted with colored lights, and made to look like other objects, such as wheelbarrows.



image by Steph
B


Most artistic unicycles have something added, since there isn’t much left to remove from a unicycle.


One goofy addition is a "handlebar unit." This is not attached to the unicycle, but pushed along, generally in front, not for assisting the rider in balancing, but for show. At first, it appears the rider is on an ordinary bicycle. But wait, there’s no frame between the front and rear wheels. Then the rider can turn the handlebar unit this way and that, hold it over head, throw it and catch it, and so on, resulting in a rather amazing show for anyone not expecting that.



image by Daniel
Oines


Your silly author added a couple of wheels to make a tall unicycle in which one tire rubbed on the one below, turning that wheel backward, and that one’s tire rubbed on the bottom wheel, turning it forward.



The author on his three-wheel unicycle


This picture is fuzzy because it was a low-quality snapshot. No one realized this picture might be important later.

Cargo


Table of Contents



image by Paretz
Partensky




Italian firefighter bicycle
image by Harlock81


What can be carried on a bicycle is amazing. Carrying too much badly is also a cause for many bike accidents, so please be careful.




A rolling shoe repair shop
image by Pivari.com




A cargo bike
image by Salim
Virji




Long wheelbase cargo bike
image by Tulio
Bertorini




image by Bernard
Gagnon




Bicycle ambulance
image by Oxyman




Stougard




Bicycle trailer with passenger




Bicycle truck




Stougard


In the mid 1980s Tom Wooten, known as Wrong Way Wooten, from Bryn Mawr, Pennsylvania, near Philadelphia, became rather famous for riding his bike backward.



Wrong Way Wooten


He built a custom bike for his purpose. It was based on a Schwinn Varsity, which was a very heavy all-steel bike of the late 1970s, with a one-piece crank. He put padded tape on the handlebar to make sitting more comfortable. He installed two mirrors on long arms so he could see where he was going. He removed the seat, and put a portable television in its place. He then somehow attached another ten-speed bike to the rear of his bike in order to carry more gear.


Wrong Way then set out on a journey across the United States with a specific self-appointed mission. "The main reason I do what I do is to get people to realize that they have a responsibility to other people." He represented several major charities including The American Cancer Society, The American Lung Society, The Heart Fund, the Jaycees, United Way, and March of Dimes, encouraging people to donate to their favorite charities. According to the legend, he criss-crossed the country several times totaling 28,000 miles (45,000 kilometers) over the next 17 years.


Derailleurs and Sprockets


Table of Contents



Simple but high-end, non-index shifters
image by Arnoooo


One of the latest changes in derailleurs isn’t in mechanical design, but in the word itself. It is slowly evolving to be spelled "derailer."



SRAM Rival rear derailleur
image by Fanny
Schertzer




SRAM Rival front derailleur image by Fanny
Schertzer




A Huret Svetto derailleur, circa 1970
image by Paco Girasol




Shimano LX e-type front derailleur image by Jeremy
Mikesell




Campagnolo Super Record rear derailleur




Single-speed bike with a chain tensioner
image by Ralf
Roletschek


above configuration seems redundant until you notice that the bike has vertical dropouts. There is no way to adjust chain tension. Many years ago, "half-links" were available, so you could adjust a chain’s length to the nearest link, not to the nearest set of two links. That was generally adequate adjustment granularity for most uses.


Let’s hope this bike has a freewheeling sprocket. If fixed gear, the first resistance against the pedals would cause the tensioner to let out all the slack.



image by Ralf
Roletschek




image by Cvosmer




Belt drive
image by Keanu @ no:wp


Brakes


Table of Contents

There are more ways to stop a bike than to make it go. Below are pictures of some interesting concepts in braking:



Spoon brake
image by AndrewDressel


One of the first brakes, called a spoon brake, just rubbed on the surface of the tire. This was common on penny-farthings (also called "ordinaries") – the bikes with huge front wheels – if they had brakes at all.




Fongers rod actuated brake on Westrick rim
image by Jeremy
Burgin


It didn’t take long to figure out that rubbing something against the rim was more durable than against the tire.



A typical old coaster brake


Coaster brakes are relatively complex mechanisms, yet they appeared early in the history of bicycles.



Generations
www.flickr.com/photos/motoyen




Early drum brake
image by Ralf
Roletschek


Something more powerful was needed for motorcycles and cars, so the drum brake was invented. This has two half-circle shoes that rub against the inside of the hub shell when actuated with a cam. Just like most caliper (rim) brakes, these work poorly when wet, unless sealed against the weather.



Modern drum brake
image by Haupseite




Band brake
image by imoni


A band brake fits loosely around the outside of a drum mounted on the hub. When actuated, the band tightens around the drum. This type of brake is used extensively on slow-moving machinery such as riding movers. Interestingly, in one direction, generally forward, the brake is easily controlled. In the other direction, as soon as the band touches the drum, it tends to tighten itself, making braking touchy. Band brakes are seldom used on bicycles.



image by Ralf
Roletschek


A very common type of brake used in bicycles is a caliper brake. There are several variations. This one is called a "centerpull" style, because the cable pulls equally on both sides. Sidepull brakes have a cable in which the inner wire pulls on one side, while the cable housing ("equal and opposite reaction") pushes on the other side.




Campagnolo Delta – a highly styled caliper brake
image by
Christian
Kunze




Rollercam brake – uses a cam instead of a bridge cable
image
by Jeff Archer





And then we have disk brakes. These are easier to keep adjusted than caliper brakes. Because the rotor is small and near the center of the wheel, it is less likely to get bent. The overall weight is low compared to other kinds of brakes.








Bits
and Pieces


Table of Contents

a Few Modern Components




image by Hauptseite




image by Ukxpat




image by KMJ




image by AndrewDressel


And
a few old ones:



image by Wp-0001


When chains and sprockets were first used with bicycles, they were adapted from farm and industrial machinery. At the time, skip-link also known as inch-pitch chain was common.



image by tetedelacourse


Sew-up tires, also known as "tubulars" are far less common today than they were until the early 1980s. These are made like an American football. They have an inner tube that is completely surrounded by the tire. The tire is sewn together with heavy stitches along the inside edge. You can inflate a sew-up off a wheel, and it will look like a giant, thin donut. They were very popular for road and track racing, since they can hold a very high pressure, and are thin and light. These are glued or fastened to the rims with double-sided tape.


The sew-up is a simple tire compared to the modern kind, called clincher.



Crosssection of a typical bicycle wheel
image by Deerwood


In the picture above:


1. The metal wheel rim.


2. The rim strip. This is a rubber, cloth or plastic strip that protects the inner tube from punctures caused by contact with the spoke heads.


3. The side of the rim where a caliper brake can be used.


4. Inside the edges of the tire are steel cables. Without these, when pressurized, the tire would stretch and blow off the rim.


5. The inner tube. Because of the small volume of air in a bicycle tire, the smallest leak would cause it to deflate quickly. Since bicycle rims usually have to accommodate spokes, it would be difficult to seal the spoke holes. Therefore, it is not practical to make a tubeless tire, such as cars use. The inner tube makes it possible to have a system that is not microscopically precise, yet is air tight.


6. The tire casing is made of cloth, and has sufficient strength and flexibility to withstand the air pressure and bumps and cracks in the road surface.


7. The tread of the tire is usually rubber impregnated with carbon. That’s why most tires are black. The carbon keeps the rubber from wearing out immediately. Without carbon, instead of 2,000 miles (3,000 km) per pair of tires, they might last 10 miles (15 km).



Wingnut


For a short while in the 1970s, wingnuts were popular. The idea is that riders would not have to use a wrench to remove and replace wheels. Even though hollow axles with quick release skewers were available then, they were somewhat more expensive.


The problem with wingnuts is that it was hard to get them tight enough. The rear wheel would typically pull to one side on a hard hill climb, so the rider would have to stop and reposition the wheel, then attempt to tighten the wingnut sufficiently. Sometimes the wings would break off. Worse, wingnuts on the front wheel could come loose by simply parking against a bush or bumping a wingnut with a shoe.


Seats or Saddles


Table of Contents



image by Ralf
Roletschek


Serious cyclists call seats "saddles."


Serious cyclists call seatposts "seat pillars."


Go figure!



image by AndrewDressel







A "banana" seat from a stingray bike of the late 1960s

image by AndrewDressel




A sprung leather saddle
image by Suleyman
Habib




The Brooks Professional, a top of the line leather seat
image
by The
Javelina




image by Hutschi


New riders are advised to limit the length of their rides until they get used to their saddles. Until a rider is quite experienced, most saddles are uncomfortable. For that reason, inventors have been working since the beginning of bicycling to come up with better alternatives.


Planetary Gearsets


Table of Contents

Only a few short years elapsed between the time when bicycles started to standardize as "safeties," and when planetary geared hubs, also called planetary gearsets, started to appear.


Safeties were bikes with same-size wheels and a chain drive from centrally located pedals with a large sprocket to the rear wheel with a smaller sprocket – in other words, the typical modern bicycle design. Before safeties, bikes had pedals attached directly to a wheel. The driven wheel had to be as large as possible. That way, each turn of the pedals would carry the bike a reasonable distance, so as to avoid being a slow-poke.


With a planetary gearset, the hub can turn different speeds than the sprocket mounted on the hub. Planetary gearsets are also known as "epicyclic gearing" or "gear hubs." The first ones showed up around 1880, but the first commercially successful two-speed planetary hub, called "The Hub," was in production starting in 1898. By 1902, a three-speed hub was available.


Now, more than a century later, planetary gearsets are still available, with versions containing as many as 14 distinct speeds.



The Rholoff Speedhub – 14 Speeds
image by
http://commons.wikimedia.org/wiki/User:Marcela">Marcela


The planetary gearset has some advantages. The system is enclosed, so is less vulnerable to weather and dirt. There’s no low-hanging chain tensioner to get bent or caught in the weeds. The chainline is simple, so easier to enclose, preventing grease marks on socks and pants. In fact, belt and fully-enclosed shaft drives work with planetary gearsets. Because a derailleur system can only be shifted when the chain is moving, the planetary gearset is easier for beginners, and commuters, who often have to shift after having come to a stop. Derailleur bikes almost always have dished rear wheels. This means that the hub flange on the right-hand side is offset toward the center of the hub in order to make room for the sprockets. A dished wheel is weaker against lateral forces. Planetary hubs can have widely spaced flanges for strong rear wheels.


The downside of planetary gearsets is that they tend to concentrate a lot of weight in the rear wheel, and may cost more.


One of the most prolific manufacturers is Sturmey-Archer, who made a hub that remained mostly unchanged for many years, and was the centerpiece of the classic European three-speed bike, which was very popular in America during the 1950s and 1960s.



Classic Raleigh Three-Speed with Sturmey-Archer Hub
image by
Degen_Earthfast


When you come across an old three-speed, you can wipe the road grime away, and read the month and year of manufacture on the outside of a Sturmey-Archer hub.





Sturmey-Archer three-speed shifter
image by huubvanhughten




image by PeterWiki,
http://commons.wikimedia.org/wiki/File:Planetengetriebe_Prinzip.jpg


Then there is a new variable speed hub design, called NuVinci that doesn’t use gears at all. There are no clicks or stops on the shifter. You can select the exact ratio you want at any time. This uses a system of cones and rollers to vary the ratio.



The NuVinci hub
image by Keanu @ no:wp




Inside the NuVinci hub
image by Keanu4


Mysteries


Table of Contents



image by Usien




image by SJu




image by SJu


Everything
Else


Table of Contents



Change – a folding mountain bike
image by Jean.rhs




image by Erik
Enfors




image by Andrew
Dressel




Bicycle for three
image by AndreasFahrrad




Bicycle workshop in a village in Burundi in the province of
Ruiyigi.
image by Andreas31




Modern six-day race
image by tetedelacourse




Start of a road race in Mendefera, Eritrea
image by David
Stanley




Road race in Belgium
image by Wouter
Hagens




Rental bikes
image by Tullia




In Amsterdam
image by Clive
Power from London








Dahon folding bike
Tine




Geoff Gallice
from Gainesville, FL, USA




Touring bike
image by Keithonearth




"Yellow Bike" (see below)
image by Wolfgangus
Mozart


This yellow bike is in Varberg, Sweden, and may be a "free rental" bike. In Portland, Oregon and various other communities throughout the world, "Yellow Bike" programs have been tried in which bikes, which are typically painted yellow, and converted to one-speed coaster brake machines, are given to the public for free use. This cuts down on pollution and noise, and reintroduces adults to bicycling who might not otherwise ride a bike. Most yellow bike programs do not last long, since the bikes tend to disappear faster than additional bikes can be added to the fleet. Most yellow bikes carried signs specifically explaining that they were free to use.



A field of bikes in Oxford, England
image by Adam
Wood




image by Halfalah




A hand and foot bike
image by www.skywheel.kr/


This is must be an interesting contraption to ride. You can power this bike with your hands as well as your feet. Notice that the handlebars are not hooked to the front wheel at all. The fork has a strong reverse camber, so leaning should be sufficient to control the bike’s direction. Starting might be disconcerting at first.




A railway bike
image by
PekePON




Leo Tolstoy’s bike
image by Moscvitch




image by Russ
from Grosse Pointe Park, USA




playground ride. Lund, Sweden.
image by Popperipopp




Doing everything wrong
image by
www.flickr.com/people/catt1788/


In the above picture, the rider has no helmet, is riding with flip flops on his feet, his seat is way too low, and look at that: he has no brake levers or cables! I think we can assume it is a test ride.



An amphibious bike created in 1932




Bicycle lawn mower
B.
Jankuloski


Table
of Contents


bike bus