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Dunlop Valve
The Dunlop valve, (also called a Woods valve or an English valve) is a type of pneumatic valve stem in use—mostly on inner tubes of bicycles—in many countries, including Japan, Korea, India, Pakistan, Sri Lanka, most European countries, and a number of developing countries. The Dunlop valve has a wider base than a Presta valve, similar enough in size to a Schrader valve to use identically drilled valve holes in rims, but it can be inflated with a Presta valve adapter. The inner mechanism of the valve can be replaced easily, without the need for special tools. The Dunlop valve originally used a tight rubber sleeve (see illustration of "original plug") which had to be forced open by air pressure while pumping (not only were these difficult to inflate, but the rubber would perish over time, allowing leakage and eventually, complete failure), but modern Dunlop valves use a different plug (core) using either an internal ball bearing or a spring-loaded rubber plug that is unseated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valve Stem
A valve stem is a self-contained valve which opens to admit gas to a chamber (such as air to inflate a tire), and is then automatically closed and kept sealed by the pressure in the chamber, or a spring, or both, to prevent the gas from escaping. They are most commonly used on automobile, motorcycle, and bicycle tires, but also for many other applications. Schrader Schrader valves consist of a valve stem into which a poppet valve is threaded with a spring attached. They are used on virtually all automobile and motorbike tires, and on wider rimmed bicycle tires. In addition to tires, Schrader valves of varying diameters are used in refrigeration and air conditioning systems, plumbing, engine fuel injection, suspension systems, and SCUBA regulators, allowing the user to remove and attach a hose while in use. The Schrader valves in the fuel injector rail of many automobiles is used as a quick and easy point to check fuel pressure or connect an injector cleaner cartridge. Presta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Developing Country
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreement on which countries fit this category. The term low and middle-income country (LMIC) is often used interchangeably but refers only to the economy of the countries. The World Bank classifies the world's economies into four groups, based on gross national income per capita: high, upper-middle, lower-middle, and low income countries. Least developed countries, landlocked developing countries and small island developing states are all sub-groupings of developing countries. Countries on the other end of the spectrum are usually referred to as high-income countries or developed countries. There are controversies over this term's use, which some feel it perpetuates an outdated concept of "us" and "them". In 2015, the World Bank declared that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Presta Valve
The Presta valve (also French valve (FV) or Sclaverand valve) is a tire valve commonly found in high pressure road style and some mountain bicycle inner tubes. It comprises an outer valve stem and an inner valve body. A lock nut to secure the stem at the wheel rim and a valve cap may also be present. Name The '' Sclaverand valve'' was invented by Frenchman Etienne Sclaverand and is often referred to as the ''French valve''. Today it is also known as ''Presta valve''. ''Presta'' or ''presto'' stands in the Romance languages for "fast, hurry, immediately". Description The outer valve stem is manufactured in various lengths for different applications and has a narrower diameter () than Dunlop and Schrader valves (). The weakest point of a bicycle rim is usually the hole for the valve stem. The smaller hole for a Presta valve makes it possible to have extremely narrow wheels while maintaining sufficient strength in the wheel. The air pressure in an inflated tire holds th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schrader Valve
The Schrader valve (also called American valve) is a type of pneumatic tire valve used on virtually every motor vehicle in the world today. The Schrader company, for which it was named, was founded in 1844 by August Schrader. The original Schrader valve design was invented in 1891, and patented in the United States in 1893. The Schrader valve consists of a valve stem into which a valve core is threaded. The valve core is a poppet valve assisted by a spring. A small rubber seal located on the core keeps the fluid from escaping through the threads. Using the appropriate tools, a faulty valve core can be immediately extracted from the valve stem and replaced with a new one. Uses The Schrader valve is used on virtually all automobile tires and motorcycle tires and most wider rimmed bicycle tires. In addition to tube and tubeless tires, Schrader valves of varying diameters are used on many refrigeration and air conditioning systems to allow servicing, including recharging with re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screw Thread
A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a ''straight'' thread and the latter called a ''tapered'' thread. A screw thread is the essential feature of the screw as a simple machine and also as a threaded fastener. The mechanical advantage of a screw thread depends on its ''lead'', which is the linear distance the screw travels in one revolution. In most applications, the lead of a screw thread is chosen so that friction is sufficient to prevent linear motion being converted to rotary, that is so the screw does not slip even when linear force is applied, as long as no external rotational force is present. This characteristic is essential to the vast majority of its uses. The tightening of a fastener's screw thread is comparable to driving a wedge into a gap until it sticks fast thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunlop Rubber
Dunlop Ltd. (formerly Dunlop Rubber) was a British multinational company involved in the manufacture of various natural rubber goods. Its business was founded in 1889 by Harvey du Cros and he involved John Boyd Dunlop who had re-invented and developed the first pneumatic tyre. It was one of the first multinationals, and under du Cros and, after him, under Eric Geddes, grew to be one of the largest British industrial companies. J B Dunlop had dropped any ties to it well before his name was used for any part of the business. The business and manufactory was founded in Upper Stephens Street in Dublin. A plaque marks the site, which is now part of the head office of the Irish multinational departments store brand, Dunnes Stores. Dunlop Rubber failed to adapt to evolving market conditions in the 1970s, despite having recognised by the mid-1960s the potential drop in demand as the more durable Radial tire, radial tyres swept through the market. After taking on excessive debt Dunlop w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Tire
A bicycle tire is a tire that fits on the wheel of a bicycle or similar vehicle. These tires may also be used on tricycles, wheelchairs, and handcycles, frequently for racing. Bicycle tires provide an important source of suspension, generate the lateral forces necessary for balancing and turning, and generate the longitudinal forces necessary for propulsion and braking. Although the use of a pneumatic tire greatly reduces rolling resistance compared to the use of a rigid wheel or solid tire, the tires are still typically, the second largest source, after wind resistance (air drag), of power consumption on a level road. The modern detachable pneumatic bicycle tire contributed to the popularity and eventual dominance of the safety bicycle. Bicycle tires are also used on unicycles, tricycles, quadracycles, tandem bicycles, hand cycles, bicycle trailers, and trailer bikes. History The first bicycle "tires" were iron bands on the wooden wheels of velocipedes. These were fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Tube
An inner tube is an inflatable ring that forms the interior of some pneumatic tires. The tube is inflated with a valve stem, and fits inside of the casing of the tire. The inflated inner tube provides structural support and suspension, while the outer tire provides grip and protects the more fragile tube. They are widely used in bicycles and are also used in many motorcycles and heavy road vehicles such as trucks and buses. They are now less common in other wheeled vehicles because of the benefits of having no tube, such as the ability to operate at low pressure and at high pressure (unlike a tube tire, which would pinch at low pressure and burst at high pressure), without going flat. Large inner rings also make effective flotation devices and are widely used in the leisure activity of tubing. Material The tube is made out of a mix of natural and synthetic rubber. Natural rubber is less prone to punctures and is often more pliable, while synthetic rubber is cheaper. Often racin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Parts
For other cycling related terms (besides parts) see Glossary of cycling. List of bicycle parts by alphabetic order: * Axle: as in the generic definition, a rod that serves to attach a wheel to a bicycle and provides support for bearings on which the wheel rotates. Also sometimes used to describe suspension components, for example a swing arm pivot axle * Bar ends: extensions at the end of straight handlebars to allow for multiple hand positions * Bar plugs or end caps: plugs for the ends of handlebars * Basket: cargo carrier * Bearing: a device that facilitates rotation by reducing friction * Bell: an audible device for warning pedestrians and other cyclists * Belt-drive: alternative to chain-drive * Bicycle brake cable: see Cable * Bottle cage: a holder for a water bottle * Bottom bracket: The bearing system that the pedals (and cranks) rotate around. Contains a spindle to which the crankset is attached and the bearings themselves. There is a bearing surface on the spindle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
