Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Wheel shopping experience:

1. Compare - without doubt the biggest advantage that the Wheel offers shoppers today is the ability to compare thousands of Wheel at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Wheel? Wrong! If the Wheel is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Wheel then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Wheel? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Wheel and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Wheel wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Wheel then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Wheel site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Wheel, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Wheel, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

has an eccentricity e with the point of contact to the rolling surface and exerts a moment about the contact point.

A wheel is a circular device capable of rotating on its axis, facilitating movement or transportation or performing labour in machines. A wheel together with an axle overcomes friction by facilitating motion by rolling. Common examples are found in transport applications. More generally the term is also used for other circular objects that rotate or turn, such as a Ship's wheel and flywheel.

History of the wheel and axle The English word :wikt:wheel comes from the Proto-Indo-European language *kwekwlo-, which was an extended form of the root *kwel- meaning "to revolve, move around". This is also the root of the Greek language κυκλος kuklos, the Sanskrit chakra, and Persian language charkh, all meaning "circle" or "wheel",http://www.bartleby.com/61/roots/IE250.html and also in Lithuanian language, sukti means "to rotate". The Latin word :wikt:rota is from the Proto-Indo-European *rotā-, the extended o-grade form of the root *ret- meaning "to roll, revolve".http://www.bartleby.com/61/roots/IE432.html.

Origin of wheels -drawn carts on the Sumerian "battle standard of Ur" (circa 2600 BC)

The wheel probably originated in ancient Sumer (modern Iraq) in the 5th millennium BC, originally in the function of potter's wheels. The wheel reached India and Pakistan with the Indus Valley Civilization in the 3rd millennium BC. Near the northern side of the Caucasus several graves were found, in which since 3700 BC people had been buried on wagons or carts (both types). The earliest depiction of what may be a wheeled vehicle (here a wagon—four wheels, two axles), is on the Bronocice pot, a ca. 3500 BC clay pot excavated in southern Poland. Waza z Bronocic (in Polish), Armenia Ancient wheel barrel. 2500 BCThe wheel reached Europe and History of India (the Indus Valley Civilization) in the 4th millennium BC. In China, the wheel is certainly present with the adoption of the chariot in ca. 1200 BC, and Barbieri-Low (2000) argues for earlier Chinese wheeled vehicles, circa 2000 BC. It is an open question whether there was an independent "invention of the wheel" in East Asia. Alternatively the concept may have made its way there after jumping the Himalayas barrier. It has even been suggested that the introduction of the wheel into China was through Chariot wielding conquerors, possibly connected to inception of the Shang Dynasty (ca. 1700 BC)Dyer, Gwynne, War: the new edition, p. 159: Vintage Canada Edition, Randomhouse of Canada, Toronto, ON.

Some archeology argue for the European origin of the wheel on an axle. Ojczyzna wozu: Europa czy Bliski Wschód (in Polish), Wiedza i Życie, 8/1996 It is claimed that natural conditions of Europe (hard-surface plains making it difficult to drag heavy loads as well as plenty of timber used by skilled craftsmen in every aspect of life) provided the best background for the invention of a wheel used for transport. The chronology of the oldest known specimens and representations of wheels and/or wheeled vehicles suggest that the invention may have been made in Europe no later than in the first half of the 4th millennium BC. The prototype for the wheeled wagon was most probably "traga na szpuli" which was a primitive sledge with wooden logs put underneath. Through contacts and Human migration the invention was spread to the peoples from the regions of the Caspian Sea and the Black Sea. From there, it reached Mesopotamia in the late 4th millennium BC. This could explain why in the Near East even the oldest wagons were already relatively highly diverse and sophisticated and no evidence of evolutionary stages of their development there have been found yet.

Although they did not develop the wheel proper, the Olmec and certain other western hemisphere cultures seem to have approached it, as wheel-like worked rock (geology)s have been found on objects identified as children's toys dating to about 1500 BC.

, in Tehran. The wheel is dated late 2nd millennium BC and was excavated at Choqa Zanbil.

The invention of the wheel thus falls in the late Neolithic and may be seen in conjunction with the other technological advances that gave rise to the early Bronze Age. Note that this implies the passage of several wheel-less millennia even after the invention of agriculture. Looking back even further, it is of some interest that although Paleoanthropology now date the emergence of anatomically modern humans to ca. 150,000 years ago, 143,000 of those years were "wheel-less". That people with capacities fully equal to our own walked the earth for so long before conceiving of the wheel may be initially surprising, but populations were extremely small through most of this period and the wheel, which requires an axle and socket to actually be useful, is not as simple a device as it may seem. Making and balancing a wheel requires a Skill (labor) Wheelwright.

Early wheels too were simple wooden disks with a hole for the axle. Because of the structure of wood a horizontal slice of a trunk is not suitable, as it does not have the structural strength to support weight without collapsing; rounded pieces of longitudinal boards are required.The oldest such wheel, believed to have been made by the Alekern tribe, was found by the Slovenian archaeologist Janez Dirjec in 2002 AD at the Ljubljana Marshes (Ljubljansko barje), some 20 kilometres southeast of Ljubljana, Slovenia. According to the experts in Vienna, Austria, the specimen was manufactured somewhere between 3350 and 3100 BC and is even older than others of similar construction found in Switzerland and Germany.

The spoked wheel was invented more recently, and allowed the construction of lighter and swifter vehicles. The earliest known examples are in the context of the Andronovo culture, dating to ca 20th century BC. Shortly later, horse cultures of the Caucasus region used horse-drawn spoked-wheel war chariots for the greater part of three centuries. They moved deep into the Greek peninsula where they joined with the existing Mediterranean peoples to give rise, eventually, to classical Greece after the breaking of Minoan dominance and consolidations led by pre-classical Sparta and Athens. Celtic chariots introduced an iron rim around the wheel in the 1st millennium BC. The spoked wheel had been in continued use without major modification until the 1870s AD, when wire wheels and pneumatic tires were invented .

The invention of the wheel has also been important for technology in general, important applications including the water wheel, the cogwheel (see also antikythera mechanism), the spinning wheel, and the astrolabe or torquetum. More modern descendants of the wheel include the propeller, the jet engine, the flywheel (gyroscope) and the turbine.

Mechanics and function .

The wheel (with axle) is considered one of the Simple machine and lies near the starting point of advanced human technology (advanced, that is, in comparison with even earlier mechanical innovations such as stone/bone knives and axes, tension-sprung projectiles, scoops and shovels).

When wheels are used in conjunction with axles, either the wheel turns on the axle or the axle turns in a vehicle (as in a cart) or a housing (as in a mill (grinding)). The mechanics are the same in either case.

The low resistance to motion (compared to dragging) is explained as follows (refer to friction):

bearing (mechanical) are used to reduce friction at the interface.

Example:

Additional energy is lost at the wheel to road interface. This is termed rolling resistance which is predominantly a deformation loss.

Wheels in nature Notably there are no macroscopic wheels in animals or plants (though some animals can Terrestrial locomotion in animals#Rolling), while microscopic wheels do exist in nature such as in ATP synthase and bacterial flagellum.

Wheeled vehicles Vehicles can be classified according to number of wheels:

  • Unicycle, monocycle
  • Bicycle
  • Tricycle
  • Quadricycle


    • Alternatives to wheels While wheels are used for ground transport very widely, there are alternatives, some of which are suitable for terrain where wheels are ineffective. Alternative methods for ground transport without wheels include:

    Wheels as symbols The wheel has also become a strong cultural and spiritual metaphor for a cycle or regular repetition (see chakra, reincarnation, Yin and yang among others).As such and because of the difficult relief, wheeled vehicles were forbidden in history of Tibet.

    The winged wheel is a symbol of progress, seen in many contexts including the coat of arms of Panama and the logo of the Ohio State Highway Patrol.

    The introduction of spoked (chariot) wheels in the Middle Bronze Age appear to have carried somewhat of a prestige. The solar wheel appears to have a significance in Bronze Age religion, replacing the earlier concept of a Solar barge with the more "modern" and technologically advanced solar chariot.

    wheel.The wheel is also the prominent figure on the flag of India. The wheel in this case represents law ("dharma).It also appears in the flag of the Romani people, hinting to their nomadic history and their Indian origins.

    In recent times, the custom aftermarket carwheel has become a status symbol. These wheels are often incorrectly referred to as "rims." The term "rim" is incorrect because the rim is only a portion of a wheel, just as with a coffee cup or meteor crater. These "rims" have a great deal of variation, and are often very shiny. Some custom "rims" include a bearing-mounted, free-spinning disc which continues to rotate by inertia after the automobile is stopped. In slang, these are referred to as "Spinner (wheel)" .

    See also . Wheel

    References

    has an eccentricity e with the point of contact to the rolling surface and exerts a moment about the contact point.

    A wheel is a circular device capable of rotating on its axis, facilitating movement or transportation or performing labour in machines. A wheel together with an axle overcomes friction by facilitating motion by rolling. Common examples are found in transport applications. More generally the term is also used for other circular objects that rotate or turn, such as a Ship's wheel and flywheel.

    History of the wheel and axle The English word :wikt:wheel comes from the Proto-Indo-European language *kwekwlo-, which was an extended form of the root *kwel- meaning "to revolve, move around". This is also the root of the Greek language κυκλος kuklos, the Sanskrit chakra, and Persian language charkh, all meaning "circle" or "wheel",http://www.bartleby.com/61/roots/IE250.html and also in Lithuanian language, sukti means "to rotate". The Latin word :wikt:rota is from the Proto-Indo-European *rotā-, the extended o-grade form of the root *ret- meaning "to roll, revolve".http://www.bartleby.com/61/roots/IE432.html.

    Origin of wheels -drawn carts on the Sumerian "battle standard of Ur" (circa 2600 BC)

    The wheel probably originated in ancient Sumer (modern Iraq) in the 5th millennium BC, originally in the function of potter's wheels. The wheel reached India and Pakistan with the Indus Valley Civilization in the 3rd millennium BC. Near the northern side of the Caucasus several graves were found, in which since 3700 BC people had been buried on wagons or carts (both types). The earliest depiction of what may be a wheeled vehicle (here a wagon—four wheels, two axles), is on the Bronocice pot, a ca. 3500 BC clay pot excavated in southern Poland. Waza z Bronocic (in Polish), Armenia Ancient wheel barrel. 2500 BCThe wheel reached Europe and History of India (the Indus Valley Civilization) in the 4th millennium BC. In China, the wheel is certainly present with the adoption of the chariot in ca. 1200 BC, and Barbieri-Low (2000) argues for earlier Chinese wheeled vehicles, circa 2000 BC. It is an open question whether there was an independent "invention of the wheel" in East Asia. Alternatively the concept may have made its way there after jumping the Himalayas barrier. It has even been suggested that the introduction of the wheel into China was through Chariot wielding conquerors, possibly connected to inception of the Shang Dynasty (ca. 1700 BC)Dyer, Gwynne, War: the new edition, p. 159: Vintage Canada Edition, Randomhouse of Canada, Toronto, ON.

    Some archeology argue for the European origin of the wheel on an axle. Ojczyzna wozu: Europa czy Bliski Wschód (in Polish), Wiedza i Życie, 8/1996 It is claimed that natural conditions of Europe (hard-surface plains making it difficult to drag heavy loads as well as plenty of timber used by skilled craftsmen in every aspect of life) provided the best background for the invention of a wheel used for transport. The chronology of the oldest known specimens and representations of wheels and/or wheeled vehicles suggest that the invention may have been made in Europe no later than in the first half of the 4th millennium BC. The prototype for the wheeled wagon was most probably "traga na szpuli" which was a primitive sledge with wooden logs put underneath. Through contacts and Human migration the invention was spread to the peoples from the regions of the Caspian Sea and the Black Sea. From there, it reached Mesopotamia in the late 4th millennium BC. This could explain why in the Near East even the oldest wagons were already relatively highly diverse and sophisticated and no evidence of evolutionary stages of their development there have been found yet.

    Although they did not develop the wheel proper, the Olmec and certain other western hemisphere cultures seem to have approached it, as wheel-like worked rock (geology)s have been found on objects identified as children's toys dating to about 1500 BC.

    , in Tehran. The wheel is dated late 2nd millennium BC and was excavated at Choqa Zanbil.

    The invention of the wheel thus falls in the late Neolithic and may be seen in conjunction with the other technological advances that gave rise to the early Bronze Age. Note that this implies the passage of several wheel-less millennia even after the invention of agriculture. Looking back even further, it is of some interest that although Paleoanthropology now date the emergence of anatomically modern humans to ca. 150,000 years ago, 143,000 of those years were "wheel-less". That people with capacities fully equal to our own walked the earth for so long before conceiving of the wheel may be initially surprising, but populations were extremely small through most of this period and the wheel, which requires an axle and socket to actually be useful, is not as simple a device as it may seem. Making and balancing a wheel requires a Skill (labor) Wheelwright.

    Early wheels too were simple wooden disks with a hole for the axle. Because of the structure of wood a horizontal slice of a trunk is not suitable, as it does not have the structural strength to support weight without collapsing; rounded pieces of longitudinal boards are required.The oldest such wheel, believed to have been made by the Alekern tribe, was found by the Slovenian archaeologist Janez Dirjec in 2002 AD at the Ljubljana Marshes (Ljubljansko barje), some 20 kilometres southeast of Ljubljana, Slovenia. According to the experts in Vienna, Austria, the specimen was manufactured somewhere between 3350 and 3100 BC and is even older than others of similar construction found in Switzerland and Germany.

    The spoked wheel was invented more recently, and allowed the construction of lighter and swifter vehicles. The earliest known examples are in the context of the Andronovo culture, dating to ca 20th century BC. Shortly later, horse cultures of the Caucasus region used horse-drawn spoked-wheel war chariots for the greater part of three centuries. They moved deep into the Greek peninsula where they joined with the existing Mediterranean peoples to give rise, eventually, to classical Greece after the breaking of Minoan dominance and consolidations led by pre-classical Sparta and Athens. Celtic chariots introduced an iron rim around the wheel in the 1st millennium BC. The spoked wheel had been in continued use without major modification until the 1870s AD, when wire wheels and pneumatic tires were invented .

    The invention of the wheel has also been important for technology in general, important applications including the water wheel, the cogwheel (see also antikythera mechanism), the spinning wheel, and the astrolabe or torquetum. More modern descendants of the wheel include the propeller, the jet engine, the flywheel (gyroscope) and the turbine.

    Mechanics and function .

    The wheel (with axle) is considered one of the Simple machine and lies near the starting point of advanced human technology (advanced, that is, in comparison with even earlier mechanical innovations such as stone/bone knives and axes, tension-sprung projectiles, scoops and shovels).

    When wheels are used in conjunction with axles, either the wheel turns on the axle or the axle turns in a vehicle (as in a cart) or a housing (as in a mill (grinding)). The mechanics are the same in either case.

    The low resistance to motion (compared to dragging) is explained as follows (refer to friction):

    bearing (mechanical) are used to reduce friction at the interface.

    Example:

    Additional energy is lost at the wheel to road interface. This is termed rolling resistance which is predominantly a deformation loss.

    Wheels in nature Notably there are no macroscopic wheels in animals or plants (though some animals can Terrestrial locomotion in animals#Rolling), while microscopic wheels do exist in nature such as in ATP synthase and bacterial flagellum.

    Wheeled vehicles Vehicles can be classified according to number of wheels:

  • Unicycle, monocycle
  • Bicycle
  • Tricycle
  • Quadricycle


    • Alternatives to wheels While wheels are used for ground transport very widely, there are alternatives, some of which are suitable for terrain where wheels are ineffective. Alternative methods for ground transport without wheels include:

    Wheels as symbols The wheel has also become a strong cultural and spiritual metaphor for a cycle or regular repetition (see chakra, reincarnation, Yin and yang among others).As such and because of the difficult relief, wheeled vehicles were forbidden in history of Tibet.

    The winged wheel is a symbol of progress, seen in many contexts including the coat of arms of Panama and the logo of the Ohio State Highway Patrol.

    The introduction of spoked (chariot) wheels in the Middle Bronze Age appear to have carried somewhat of a prestige. The solar wheel appears to have a significance in Bronze Age religion, replacing the earlier concept of a Solar barge with the more "modern" and technologically advanced solar chariot.

    wheel.The wheel is also the prominent figure on the flag of India. The wheel in this case represents law ("dharma).It also appears in the flag of the Romani people, hinting to their nomadic history and their Indian origins.

    In recent times, the custom aftermarket carwheel has become a status symbol. These wheels are often incorrectly referred to as "rims." The term "rim" is incorrect because the rim is only a portion of a wheel, just as with a coffee cup or meteor crater. These "rims" have a great deal of variation, and are often very shiny. Some custom "rims" include a bearing-mounted, free-spinning disc which continues to rotate by inertia after the automobile is stopped. In slang, these are referred to as "Spinner (wheel)" .

    See also . Wheel

    References



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    Wheel



     
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