Welcome to the I Can't Sleep Podcast,
Where I help you drift off one fact at a time.
I'm your host,
Benjamin Boster,
And today's episode is about bicycles.
Thank you Heidi Hartig for sponsoring today's episode.
She wants to say happy birthday to my Steve.
A bicycle,
Also called a pedal cycle,
Bike,
Pushbike,
Or cycle,
Is a human-powered or motor-assisted,
Pedal-driven,
Single-track vehicle with two wheels attached to a frame,
One behind the other.
A bicycle rider is called a cyclist or bicyclist.
The bicycle was invented in Europe in the 19th century.
By the early 21st century,
There were more than 1 billion bicycles.
Bicycles are the principal means of transport in many regions.
They are also popular for recreation and have been adapted to use as children's toys.
Bicycles are used for commuting,
Shopping,
Fitness,
Military and police applications,
Courier services,
Bicycle racing,
And artistic cycling.
The basic shape and configuration of a typical upright or safety bicycle has changed little since the first chain-driven model was developed around 1885.
However,
Many details have been improved,
Especially since the advent of modern materials and computer-aided design.
These have allowed for a proliferation of specialized designs for many types of cycling.
In the 21st century,
Electric bicycles have become popular.
The bicycle's invention has had an enormous effect on society,
Both in terms of culture and of advancing modern industrial methods.
Several components that played a key role in the development of the car were initially invented for use in the bicycle,
Including ball bearings,
Pneumatic tires,
Chain-driven sprockets,
And tension-spoked wheels.
The dandy horse,
Also called Dresian,
Or Laufmaschine,
Running machine,
Was the first human means of transport to use only two wheels in tandem,
And was invented by the German baron Carl von Dreis.
It is regarded as the first bicycle,
And von Dreis is seen as the father of the bicycle.
But it did not have pedals.
Von Dreis introduced it to the public in Mannheim in 1817 and in Paris in 1818.
The riders sat astride a wooden frame supported by two inline wheels and pushed the vehicle along with their feet while steering the front wheel.
The first mechanically propelled two-wheeled vehicle may have been built by Kirkpatrick Macmillan,
A Scottish blacksmith in 1839,
Although his claim is often disputed.
In the early 1860s,
The Frenchmen Pierre Michaux and Pierre Lamont took bicycle design in a new direction by adding a mechanical crank drive with pedals on an enlarged front wheel,
The Velocipede.
This was the first in mass production.
Another French inventor named Douglas Grasso had a failed prototype of Pierre Lamont's bicycle several years earlier.
Several inventions followed using rear-wheel drive,
The best known being the rod-driven Velocipede by Scotsman Thomas McCall in 1869.
In the same year,
Bicycle wheels with wire spokes were patented by Eugène Meyer of Paris.
The French vélocipède,
Made of iron and wood,
Developed into the penny farthing,
Historically known as an ordinary bicycle,
A retronym since there was then no other kind.
It featured a tubular steel frame on which were mounted wire-spoked wheels with solid rubber tires.
These bicycles were difficult to mount,
Dismount and brake due to their high seat over the large front wheel.
In 1869,
Rowley Turner,
A sales agent of the Coventry Sewing Machine Company,
Which soon became the Coventry Machinist Company,
Brought a Michaux cycle to Coventry,
England.
His uncle Josiah Turner and business partner James Starley used this as a basis for the Coventry Model in what became Britain's first cycle factory.
The dwarf ordinary addressed some of these faults by reducing the front wheel diameter and setting the seat further back.
This,
In turn,
Required gearing,
Effected in a variety of ways,
To efficiently use pedal power.
Having to both pedal and steer via the front wheel remained a problem.
Lawson and Shergold solved this problem by introducing the chain drive,
Originated by the unsuccessful bicyclette of Englishman Henry Lawson,
Connecting the frame-mounted cranks to the rear wheel.
These models were known as safety bicycles,
Dwarf safeties,
Or upright bicycles for their lower seat height.
Although without pneumatic tires,
The ride of the smaller wheeled bicycle would be much rougher than that of the larger wheeled variety.
Starley's 1885 Rover,
Manufactured in Coventry,
Is usually described as the first recognizable modern bicycle.
Soon,
The seat tube was added,
Which created the modern bike's double triangle diamond frame.
Further innovations increased comfort and ushered in a second bicycle craze,
The 1890s golden age of bicycles.
In 1888,
Scotsman John Boyd Dunlop introduced the first practical pneumatic tire,
Which soon became universal.
Willie Hume demonstrated the supremacy of Dunlop's tires in 1889,
Winning the tire's first ever races in Ireland and then England.
Soon after,
The rear freewheel was developed,
Enabling the rider to coast.
This refinement led to the 1890s invention of coaster brakes.
Derailleur gears and hand-operated Bowden cable pole brakes were also developed during these years,
But were only slowly adopted by casual riders.
In the 1870s,
Many cycling clubs flourished.
They were popular in a time when there were no cars on the market,
And the principal mode of transportation was horse-drawn vehicles.
Among the earliest clubs was the Bicycling Touring Club,
Which has operated since 1878.
By the turn of the century,
Cycling clubs flourished on both sides of the Atlantic,
And touring and racing became widely popular.
The Raleigh Bicycle Company was founded in Nottingham,
England in 1888.
It became the biggest cycle manufacturer in the world,
Making over 2 million bikes per year.
Bicycles and horse buggies were the two mainstays of private transportation,
Just prior to the automobile.
And the grading of smooth roads in the late 19th century was stimulated by the widespread advertising,
Production,
And use of these devices.
More than one billion bicycles had been manufactured worldwide by the early 21st century.
Bicycles are used for transportation,
Bicycle commuting,
And utility cycling.
The energy taken to cycle to a particular distance takes less than the energy to walk as far by four-fifths,
Or 80%.
They are also used professionally by mail carriers,
Paramedics,
Police,
Messengers,
And for deliveries.
They are also used for fun,
Including bicycle touring,
Mountain biking,
Physical fitness,
And play.
The bicycle has been continually adapted and improved.
Modern materials and computer-aided design have made bicycles safer and more comfortable.
And help to create many more types of bicycle.
Bicycles can be categorized in many different ways,
By function,
By number of riders,
By general construction,
By gearing,
Or by means of propulsion.
A bicycle stays upright while moving forward by being steered,
So as to keep its center of mass over the wheels,
That is in line with the resultant force of gravity and centrifugal force.
This steering is usually provided by the rider,
But under certain conditions may be provided by the bicycle itself.
The combined center of mass of a bicycle and its rider must lean into a turn.
This lean is induced by a method known as counter-steering,
Which can be performed by the rider turning the handlebars directly with the hands,
Or indirectly by leaning the bicycle.
Short wheelbase or tall bicycle,
When braking,
Can generate enough stopping force at the front wheel to flip longitudinally.
The bicycle is extraordinarily efficient in both biological and mechanical terms.
The bicycle is the most efficient human-powered means of transportation,
In terms of energy a person must expend to travel a given distance,
When traveling slowly or equipped with an aerodynamic fairing.
From a mechanical viewpoint,
Up to 99% of the energy delivered by the rider into the pedals is transmitted to the wheels,
Although the use of gearing mechanisms may reduce this by 10-15%,
And there is also a small amount of tire slip.
A human traveling on a bicycle at low to medium speeds of about 16 to 24 kilometers per hour,
Or 10 to 15 miles per hour,
Uses only the power required to walk.
Air drag,
Which is proportional to the square of speed,
Requires dramatically higher power outputs as speeds increase.
If the rider is sitting upright,
The rider's body creates about 75% of the total drag of the bicycle-rider combination.
Drag can be reduced by seating the rider in a more aerodynamically streamlined position.
Drag can also be reduced by covering the bicycle with an aerodynamic fairing.
One bicycle may have up to a thousand parts.
Most modern bicycles have a frame with upright seating that looks much like the first chain drive bike.
These upright bicycles frequently have a diamond frame,
A truss consisting of two triangles,
The front triangle and the rear triangle.
The front triangle consists of the top tube and down tube connected by the head tube and seat tube.
The head tube contains the headset,
The set of bearings that allows the fork to turn smoothly for steering and balance.
The rear triangle consists of the seat tube,
With a bottom bracket at the bottom,
And paired chain stays and seat stays,
Connecting at the rear dropouts,
Where the axle for the rear wheel is held.
The frame shape allows the rider's weight to be distributed in a way that does not misshapen or compress the entire frame as it turns.
Another style is a recumbent bicycle.
These are inherently more aerodynamic than upright versions,
As the rider may lean back onto a support and operate pedals that are on about the same level as the seat.
Historically,
Materials used in bicycles have followed a similar pattern as in aircraft,
The goal being high strength and low weight.
Since the late 1930s,
Alloy steels have been used for frame and fork tubes in higher quality machines.
By the 1980s,
Aluminum welding techniques had improved to the point that aluminum tube could safely be used instead of steel.
Since then,
Aluminum alloy frames and other components have become popular due to their light weight,
And most mid-range bikes are now aluminum alloy.
More expensive bikes sometimes use titanium,
Or more often carbon fiber,
Laid up in resin due to its significantly lighter weight and profiling ability,
Allowing designers to make a bike both stiff and compliant by arranging the angles of the laid up fibers optimally.
The drivetrain begins with pedals which rotate the cranks,
Which are held in axis by the bottom bracket.
Most bicycles use a chain to transmit power to the rear wheel.
A very small number of bicycles use a shaft drive to transmit power.
Hydraulic bicycle transmissions have been built,
But they can be inefficient and complex.
Since cyclist's legs are most efficient over a narrow range of pedaling speeds,
Or cadence,
A variable gear ratio helps the cyclist to maintain an optimum pedaling speed while covering varied terrain.
Some,
Mainly utility bicycles,
Use hub gears with between 3 and 14 ratios.
But most use the generally more efficient derailleur system,
By which the chain is moved between different cogs,
Called chainrings,
And sprockets,
To select a ratio.
A derailleur system normally has two derailleurs,
Or mechs.
One at the front to select the chainring,
And another at the back to select the sprocket.
Most bikes have 2 or 3 chainrings,
And from 5 to 12 sprockets on the back,
With the number of theoretical gears calculated by multiplying front by back.
In reality,
Many gears overlap or require the chain to run diagonally,
So the number of usable gears is fewer.
The handlebars connect to the stem that connects to the fork housing the front wheel.
The whole assembly rotates about the steering axis,
Held by the headset bearings.
Three styles of handlebar are common.
Upright handlebars,
The norm in Europe and elsewhere until the 1970s,
Curve gently back towards the rider,
Offering a natural grip and comfortable upright position.
Drop handlebars drop as they curve forward and down,
Allowing the cyclist to use either a more aerodynamic,
Crouched position,
Or a more upright position.
Saddles also vary with rider preference,
From the cushioned ones,
Favored by short distance riders,
To narrower saddles,
Which allow more room for leg swings.
Comfort depends on riding position.
With comfort bikes and hybrids,
Cyclists sit high over the seat,
Their weight directed down onto the saddle,
Such that a wider and more cushioned saddle is preferable.
For racing bikes,
Where the rider is bent over,
Weight is more evenly distributed between the handlebars and the saddle.
The hips are flexed,
And a narrower and harder saddle is more efficient.
Differing saddle designs exist for male and female cyclists,
Accommodating the gender's differing anatomies and sit bone widths measurements,
Although bikes are typically sold with saddles most appropriate for men.
Suspension seat posts and seat springs provide comfort by absorbing shock,
But can add to the overall weight of the bicycle.
Bicycle brakes may be rim brakes,
In which friction pads are compressed against the wheel rims.
Hub brakes,
Where the mechanism is contained within the wheel hub.
Or disc brakes,
Where pads act on a rotor attached to the hub.
Most road bicycles use rim brakes,
But some use disc brakes.
Disc brakes are more common for mountain bikes,
Tandems,
And recumbent bicycles than on other types of bicycles due to their increased power coupled with an increased weight and complexity.
With hand-operated brakes,
Force is applied to brake levers mounted on the handlebars and transmitted via Bowden cables or hydraulic lines to the friction pads.
Which apply pressure to the braking surface causing friction which slows the bicycle down.
A rear hub brake may be either hand operated or pedal actuated,
As in the back pedal coaster brakes,
Which were popular in North America until the 1960s.
Bicycle suspension refers to the system or systems used to suspend the rider and all or part of the bicycle.
This serves two purposes.
To keep the wheels in continuous contact with the ground,
Improving control,
And to isolate the rider and luggage from jarring due to rough surfaces,
Improving comfort.
Bicycle suspensions are used primarily on mountain bicycles,
But are also common on hybrid bicycles,
As they can help deal with problematic vibration from poor surfaces.
Suspension is especially important on recumbent bicycles,
Since,
While an upright bicycle rider can stand on the pedals to achieve some of the benefits of suspension,
A recumbent rider cannot.
Basic mountain bicycles and hybrids usually have front suspension only.
Whilst more sophisticated ones also have rear suspension.
Road bicycles tend to have no suspension.
The wheel axle fits into fork ends in the frame and fork.
A pair of wheels may be called a wheel set,
Especially in the context of ready-built,
Off-the-shelf,
Performance-oriented wheels.
Tires vary enormously depending on their intended purpose.
Road bicycles typically use tires from 25 mm or 1 inch to 35 mm or 1.
4 inches wide,
Sometimes completely smooth or slick,
And inflated to high pressure to roll fast on smooth surfaces.
Off-road tires are usually wider,
From 30mm or 1.
2 inches to 100mm or 4 inches,
And have treads for gripping in muddy conditions or metal studs for ice.
Some components,
Which are often optional accessories on sports bicycles,
Are standard features on utility bicycles to enhance their usefulness,
Comfort,
Safety,
And visibility.
Fenders with spoilers,
Mud flaps,
Protect the cyclist and moving parts from spray when riding through wet areas.
The chain guards protect clothes from oil on the chain,
While preventing clothing from being caught between the chain and chain set teeth.
Front mounted baskets,
Front or rear luggage carriers or racks,
And panniers,
Mounted above either or both wheels,
Can be used to carry equipment or cargo.
Parents sometimes add rear-mounted child seats,
An auxiliary saddle fitted to the crossbar,
Or both to transport children.
Bicycles can also be fitted with a hitch to tow a trailer for carrying cargo,
A child,
Or both.
Toe clips,
Toe straps,
And clipless pedals help keep the foot locked into the proper pedal position,
And enable cyclists to pull and push the pedals.
Other accessories include lights,
Reflectors,
Mirrors,
Racks,
Trailers,
Bags,
Water bottles and cages,
And bells.
It is more common to see bicycles with pothole generators,
Dynamos,
Lights,
Fenders,
Racks,
And bells in Europe.
Bicyclists also have specialized form fitting and high visibility clothing.
A bicycle can be kept in good condition for decades.
Like all products with mechanical moving parts,
Bicycles require regular maintenance and replacement of worn parts.
A bicycle is relatively simple compared with a car,
So some cyclists choose to do at least part of the maintenance themselves.
Full services are available from Bicycle Mechanics at local bike shops.
In areas where it is available,
Some cyclists purchase roadside assistance from companies such as the Better World Club or the American Automobile Association.
The most common roadside problem is a puncture of the tire's inner tube.
Some brands of tires are much more puncture resistant than others,
Often incorporating one or more layers of Kevlar.
The downside of such tires is that they may be heavier and more difficult to fit and remove.
There are specialized bicycle tools for use both in the shop and at the roadside.
Many cyclists carry toolkits.
