Presented by: SUSHIL LAMBA (10406EN008)

UPPU HARISH (10406EN015)

Timeline of the Bicycle

1791•Toy-like machine which was simply a wooden beam on two wheels and propelled by the rider himself

1817•Hobby-Horse or Draisienne (after the German Baron von Drais) or Velocifere

1839•The first true bicycle “Velocipede” developed by a Scottish blacksmith named Kirkpatrik Macmillan

1863

•The first commercially successful bicycle “Velocipede” developed by Pierre Michaux also called as “BoneShaker”

1870•High wheeled bicycles or “Penny Farthing” developed by James Starley

1879•“The Safety Machine” which was chain driven was patented by Henry.J.Lawson, also known as “Bicyclette”

1889•The Rover Safety completes the development of the bicycle form.

Hobby Horse (1791)

A wooden beam on two wheels, one behind

the other

Rider sat on the beam and drove the

machine by pushing his feet alternately

against the ground, as if skating

One could not turn this machine except by

lifting and dragging front wheel

It was displayed for the first time in 1791 in a

Parisian park as “Plaything of the Rich”

Draisienne (1817)

The first notable improvement in the hobby

horse was introduced by Baron von Drais

when the front wheel was turned by a

handle

The steerable front wheel was an important

addition

A man on Draisienne could exceed thespeed of runners or even horse driven carts

The awkward posture of the rider brought

ridicule

Bumpy ride on solid wheels over rough roads

resulted in many cases of hernia

The Treadle and Crank (1830)

First true bicycle which could be ridden with

both feet entirely off the ground (out of mud)

Kirkpatrik Macmillan employed the power ofleg muscles to turn the rear wheel instead of

dragging

Mechanism involves two bars suspended

from front end of the frame, whose lowerends, known as treadles, carried pedals

which were driven alternately by feet.

The linkage through the connecting rod and

crank the push and pull to rotary motion of

the rear wheel

Bone-shaker (1863)

First commercially successful bicycle

Developed by Pierre Michaux

It had a pair of pedals connected to the

front wheel and was ridden in same manner

as the basic children’s tricycles of today

Its wooden wheels with iron tyres on cobbled

roads gave the rider a very rough ride and

hence, nicknamed as Bone-Shaker

However, some comfort was achieved by

having seat on the leaf spring

The Penny Farthing (1870)

For a bone shaker to move at speeds of

modern bicycles, one would have to pedal

at very high RPM which would not at all becomfortable

Hence, the main aim was to increase the

velocity ratio

A simple and obvious way to increase the

velocity ratio was to use a larger front wheel

However, with the increase in velocity ratio,

there was a decrease in mechanical

advantage

The Safety Machine (1879)

These were low machines in which the

rider sat between two wheels and

paddled a low crank which drove the

rear wheel through a chain

However, it was identified that the size of

the wheel no longer determined the

velocity ratio

The low and rearward centre of gravityremoved the tendency of the machine to

come a cropper and hence called as

safety

A video presentation

DESIGN OF BICYCLE

Bicycle

Frame Seat Wheels

Rim

Spokes

Tire

Brakes Gears

1. WHEEL

• In the early days of bicycle development, the wheels were made of wooden spokes as used

in carts. These wooden spokes were very bulky to support the compression load.

• The first breakthrough in the wheel design came with Penny-Farthings. The load was carried

by thin wire spokes from the top portion of the rim, rather than being supported by thick

columnar spokes on the lower portion of the rim.

• The earlier tensioned-wire spokes ran straight in to the centre of the wheel. These spokes

could take the vertical load at the hub but couldn’t transmit the torque at the hub to the

rim. A couple of rigid bars with their own tensioned spokes were added for the purpose.

• This problem was solved by placing the spokes tangent to the hub.

• When a torque was applied to the hub of such a wheel through its sprocket, the wire-spokes

were tensioned, driving the rim in the same direction. A series of triangles formed by spokes

and the hub ensured that all loads were resisted by just the tensioning of spokes.

Pneumatic Tyres

• The air-filled tyres of modern bicycles were

first introduced on the safety bicycles in

1888.

• The air is contained in a thin pressurized

inner tube which is protected by a thicker

outer tyre.

• It has two steel-wire beads which snap into

grooves in the wheel rim keeping the tyre

in place.

Fig.: Cross-section of a Rim

2. BEARINGS

• The typical design of a bicycle bearing consists of a row of balls rolling between an outer

cup and an inner cone.

• The balls, cone and the cup, all are made of hardened steel to resist wear and

deformation.

Fig: A section of the front hub bearing

3. CHAIN The modern bush-roller chain was designed in 1880. It has high efficiency,

low weight and long life.

4. Free Wheel

• A free wheel is a device which connects the sprocket of the driven wheel to its

hub.

• It engages the wheel to the sprocket

when the sprocket rotates in the

forward direction, but lets the wheel roll

forward freely when the sprocket runs in

the backward direction.

5. Brakes

• The earliest of the bicycle brakes

consisted of just a metal spoon which was

operated by a hand lever and was

pressed against the rim of the front wheel.

It was effective only on a solid rubber

tyre.

• Later on, stirrup brake was developed. It is

still used on many bicycles. Modern

bicycles use calliper brakes.

The stirrup brakes operate

on the underside of the rim.

The friction pressure is build

up using lever mechanisms

that transmits the motion of

hand operated brake lever

to the brake pads with a

large value of mechanical

advantage.

Calliper brakes operate against the

sides of the rim. The outer sleeve is

attached at A and the inner cable at

B

Calliper brakes are operated through a flexible

cable which is made up of an inner-wire running

through an outer sleeve. The tension and

compression act on the two halves of the calipers

closing the brake shoes against the rim.

6. Frame

• The classical diamond frame is

well triangulated and quite

efficient. It has been the standard

frame since last 100 years.

• The top member resists load by

bending. The bending is reduced in

the other arrangement, resulting in

much more efficient structures.

7. Derailleur Gears

A transmission system consisting of a

chain, multiple sprockets, and a

mechanism (derailleur) to shift the chain

from one sprocket to another (more

common than hub gears).

Move lever on handlebar, changes

tension in derailleur cable.

Change in tension moves derailleur to one

side or the other moving the chain from

one sprocket to another.

There are two pulleys: the guide pulley

and the tension pulley. Guide pulley

pushes chain from one sprocket to the

other. The tension pulley maintains tension

in the chain.

Chainless Bicycles

These have Shaft Drives

which use precisely cut gears

and shaft rod to smoothly

and efficiently transfer power

from the pedals to the rear

wheel

Runs quieter, shifts smoother

and last longer than bikes

with chains.

These will be less expensive

and less work to maintain

Also, called as Dynamic

Bicycles use the Sussex ShaftDrive System (SDS)

When the bicycle was invented, people never thought that

this “machine” will be closely related to culture and society.

Well, sometimes unexpected things can happen, like in this

case, considering that the appearance of the bicycle

influenced the entire world!

Helping the Environment

•Cycling is not only important to the health of the

people riding, but also those of the surrounding

environment

•The bicycle does not pollute any air or sound.

More bicycles, less cars, more green space. In

conclusion, a healthy environment for all of us.

Helping our health

•A lot of diseases, like obesity or cardiovascular

diseases are increasing. But, we all have a

sedentary lifestyle, because we find no time for

practicing sports.

•We can use the bicycle in our daily activities,

and in this way we can get the “sports benefits”.

Economical help

•We all need a device for our

mobility (in a faster way), but cars

are not “available” for all of us.

In this case, bicycles are the most

useful for us.

•Bicycles are more cheaper than

cars, and they don’t need any

taxes or fuels to be paid;

The involvement in culture

•The appearance of bicycles and their evolution, the innovations

according this device and the changements made by the first called

“The Walking Machine”, have led to the apparition of museums

and important exhibitions of bicycles in the entire world

• In sports, cycling and the competitions dedicated to it, are

bringing more and more tourists and lovers of bicycles

together, spreading the culture in terms of cycling, bikes,

athletes of this sports and the history of this machine,all

over the world.

EuroBike in France

Technical Museum-Bucharest

France Tour

http://www.jimlangley.net/ride/bicyclehistorywh.html

http://www.arvindguptatoys.com_arvindgupta_bicyclestory

english.pdf

http://www.google.com/images

http://www.exploratorium.edu/cycling

http://resource.www.pedalinghistory.com