Pomelo is very large citrus fruit of botanical name Citrus maxima. It is very sweet taste after ripening . Have you ever tried a honey pomelo ? This large citrus fruit can be found in the produce section from late fall to early spring. Here's more about this tasty unique citrus fruit.The fruit is used in many festive celebrations throughout Southeast Asia. After a Captain Shaddock of an East India Company ship introduced it to Barbados, the fruit was called "shaddock" in English. The fruit is also known as jabong in Hawaii and jambola in varieties of English spoken in South Asia. The etymology of the word "pomelo" is uncertain. It may be an alteration of "pompelmoes", in Tamil pomelo are called pampa limasu, which means "big citrus". The name was adopted by the Portuguese as pomposos limoes and then by the Dutch as pompelmoes. Typically, the fruit is pale green to yellow when ripe, with sweet white ( or, more rarely , pink or red) fle...
Chassis of motorcycle includes the frame and suspension along with the front forks, of the vehicle.
Frame is typically made from welded aluminium or steel struts, with the rear suspension being an integral component in the design. Carbon-fiber, titanium and magnesium are used in a few very expensive custom frames.
The frame includes the head tube that holds the front fork and allows it to pivot. Some motorcycles include the engine as a load-bearing stressed member, this has been used all through motorcycle history but is now becoming more common.
Oil-in-frame chassis, where the lubricating oil is stored in the frame of the motorcycle, was used for Vincent motorcycles of the 1950s, and for a while during the 1970s on some NVT British motorcycles. It was widely unpopular and generally regarded as a bad idea at the time. Today it is a used on some "thumpers" (single cycle four-stokes) that usually have dry-sump lubrication requring oil tank. It has since gained some cached in the modern custom bike world too because of the saving it can afford and the reference to an earlier era.
Buell motorcycles employed a similar design with the oil held in the swingarm and fuel held in the freame.
Suspension
Modern designs have the two wheels of a motorcycle connected to the chassis by a suspension arrangement, however chopper style motorcycles often elect to forgo rear suspension, using a rigid frame.
The front suspension is usually built into the front and may consist of telescoping tubes called fork tubes which contain the suspension inside or some multibar linkage of front suspension system which is Earles type which highly used off-road motorcycles.
History:
Epicyclic gears were used in bicycle hubs before they were used on tricycles. Patent for the Epicicle Hub from the mid-1880s. The first patent for a compact epicyclic hub gear was in 1895 in Noblesville, Indiana, USA. American machinist saver was given to Thomas Johnson. It was a 2-speed, but not commercially successful.
In 1896, William Reilly of Salford, England patented the 2-speed hub, which went into production in 1898 as 'The Hub'. It was a major success, remaining in production for a decade. This established the practicality of an increasingly compact epicyclic hub gear.
By 1902, Reilly designed a 3-speed hub gear. He partnered the company with the creator of 'The Hub', but signed away from him for intellectual rights to his future gear designs. To circumvent this problem, Reilly's patents for 3-speed were obtained in the name of his colleague James Archer. Meanwhile, the noted English journalist and inventor Henry Sturmie also invented the 3-speed hub. In 1903, the head of the Raley Bicycle Company, Frank Boden, formed The Three-Speed Gear Syndicate, which acquired the rights to both the Reilly / Archer and the Starmi 3-Speed. Reilly's hub first went into production as the Stormy Archer 3-Speed.
In 1902, Mikel Pedersen (who also produced the Dursley Pedersen bicycle) patented the 3-speed hub gear and it was manufactured in 1903. It was based on the "counter shaft" principle , but arguably an unusual epicyclic gear, using a second sun in place of the ring gear. In 1904, Fichtel & Sachs Company (Germany, Schweinfurt) produced a hub gear under license to Vander and by 1909 there were 14 different 3-speed hub gears in the British market.
By the 1930s, hub gear was used on bicycles around the world. They were particularly popular in Britain, the Netherlands, German-speaking countries, and Scandinavia. Since the 1970s, they have become much less common in English-speaking countries, but in many parts of Northern Europe, where bicycles are used only as daily transport for sport or leisure, hub gear is still Are also widely used. Cheaper and stronger (but less reliable) derailleur systems, which offer a wider gear range, are now visible.
By 1987, Sturmey-Archer made only 3- and 5-speed hubs, and Fichtel & Sachs and Shimano made only 2- and 3-speed hubs. That year, the first book (other than service manuals) for some 80 years was working solely with Epicyclic bicycle gear. Since then, there has been a slow but steady increase in interest in hub gear, reflected in the broad range of products available so far.
Early Newwin Hub
Nuwania interns
In 1995, Sachs introduced the first hub gear announcement with 12 speeds and an overall range of 339%. Three years later, the Rohloff Speedbub came out with a 500/14, 14-speed gear hub, and a 526% range, equivalent to a 27-speed derriouler gear system, and also sufficiently strong and lightweight for mountain biking. In 2007, Nuuriné began manufacturing a continuously variable transmission ("stepless") h-speed hub for commuter bicycles, with an increasing range of about 380% (2016).
As of 2008, Sturmey-Archer makes 3-, 5- and 8-speed hubs, SRAM (successor to Fichtel & Sachs) makes 3-, 5-, 7- and 9-speed, and Shimano 3-, 7- and 8 makes. -speeds. In February 2010, Shimano announced the introduction of the 11-speed model Shimano Elphin 700.
Although most hub gear systems use a rear sprocket, SRAM's dual drive system combines an epicyclic hub with a multi-speed rear derailleur system, which provides a drivetrain centered on the rear wheel. In 2010, Canyon introduced the 1442, a hybrid hub that uses a similar epicyclic / daryleur combination.
The Brompton bicycle has its own design, with a two-speed derailleur attached to a special three-speed wide-ratio stormy-archer hub, the "BWR" (Brompton Wide Ratio). This system is useful for folding bicycles (where many front chainsets can fault the bike's folding mechanism), recycle bicycles, and freight bicycles (where shorter wheels and / or increased weights require a wider range in shorter steps ). Hub gears have also been used on motorcycles in the past, although this is rare now.
Operating principle
The simplest 3-speed hubs use a single planetary epicyclic gearset. The sun gear (in yellow above) is solidly mounted on the axle and thus fixed relative to the bicycle frame.
In low gears, the sprocket annulus (above in red) and the planet carrier (in green above) drives the hub, causing gear reduction.
In the middle gear, the sprocket drives the hub directly.
In high gears, the sprocket drives the planet carrier and the annulus drives the hub, resulting in an increase in gear.
The hub axle of the hub gear (unlike a derailleur system) will carry torque to all gears except direct drive, and therefore must be securely braced aga.
Disadvantage:
Selecting another gear while pedaling can be difficult or impossible, as pressure release is required to enable change in this case.
The rear wheel cannot be completely separated from a bicycle with the hub gear without disconnecting the gear gear, which complicates the process of replacing an inner tube (by disengaging the tire partwise to patch the hole Can still be performed by fixing a flat).
The hub gear is an integral part of the wheel and it is not possible to change the wheel without changing the hub gear as well.
Hub gears are more complex and generally more difficult for the rider to repair, especially on the side of the road.
Hub gears are generally more expensive than derailleur systems.
At the level of commuter / entertainment power, current hub gears are typically about 2% less efficient than suitably made derailleur gears.
Hub gears are heavier than derailleur systems with similar gearing characteristics, and the extra weight is focused on the rear wheel. This indefinite load on rear-suspension bicycles in sport use may have an adverse effect on traction and braking.
Hub gears are generally incompatible with quick release mechanisms / skewer axles.
Sometimes it is possible to select a gear without changing gears with a poorly adjusted gear cable, resulting in complete loss of drive.
Hub comes in everyday use
Conventional hub gears are indexed to the shifter, making operation dependent on the correct cable tension (and smoothness). In practice, gear-jumping and resulting internal damage are uncommon, except in high-gain units. Modern hub gear-units incorporate indexing within the unit and are, therefore, unaffected by shifting malfunctions in this way.
Most Stormy-Archer and Fishtail and Sachs "torpedo" systems default to top gear in slack gears, which can make the bicycle usable for long-distance travel on flat terrain, even if a fault in the change mechanism develops. Ho. It is like a derailleur system, which can be manually set to a higher gear in case of a similar fault. However, the earliest Stormy-Archer hubs defaulted to lower gears. Some modern hub gear systems, such as the 7-speed Shimano, also default to bottom gears and thus rely more on cable-bridge.
Hybrid gearing with derailleur
Some systems connect internally geared hubs with external derailers. A freewheeling hub with a sprocket suitable for narrow chains can be combined with a double or triple crankset and front derailleur to provide a wider range and closer gear ratio spacing. A chain tensioner or a rear derailleur is required to take a chain slack, and care is required not to over-torque the hub using a very small chaining / sprocket ratio.
Alternatively, some hubs may accept two dished drive sprockets, between which the rider can switch with the rear deflator. Careful sprocket selection may allow available gear ratios when using one sprocket to fall halfway between those when using a second sprocket, providing half-stage gearing, as in the Brompton 6-speed Folding occurs on a bicycle. This concept is used and extended in SRAM dual drive systems, where a conventional multi-speed cassette is mounted on a 3-speed hub. A similar version of the ever-popular AW Hub is produced by Stormy Archer. This system can be useful on bicycles that cannot accept a front derailleur. The German company Canyon introduced the 1442 in 2010, a hybrid hub that uses a similar EpicMichael / derailleur combination.
When both front and rear derailleurs with gear hubs are used, the result is a much wider drivetrain at the expense of increased load and complexity.
A special use of dualdrive systems is to start with a recumbent bicycle, where starting at a standstill, or after hard braking, if a high gear is engaged, is very difficult. On an upright bicycle, if a high gear is in place, the rider may use one foot to achieve minimal speed and use his upper body to balance the bike by standing on the paddle; This is not possible on a 2-wheel recumbent bicycle. The dualdrive setup here allows a deadlock or shifting at low speeds, which is not possible with derailleur gear alone
Advantage of Hub Gears
Advanced hub gears provide a greater number of gears using multiple EpicClick gears operated by each other. Their ratios are chosen to give more evenly spaced gears and a larger total gear range. The operating principle of such units is the same with less advanced systems, with trigger or twist shifter with gradual shifting.
The 12-speed Sachs announcement was the first hub gear to have 10 or more speeds in the market (1995–1999). It was considered heavy and plagued with quality issues, and was discontinued after a few years.
The 14-speed Rohloff SpeedHub hub gear introduced in 1998 has a range from 5 to 1, and thus is comparable to the 24, 27 and 30-speed derriouler systems (3x8, 3x9 and 3x10 jogs with front and rear). Since the latter has three overlapping ranges, containing only about 14 different gears. As there is no overlap with the SpeedHub, the hub gear has only two shift directions (up and down), compared to the front and rear derailleur gears where shifting through all gears with two shift operators is required.
The 11-speed Shimano Alfin 700 hub gear launched in 2010 has a gear-range of 4 to more than 1, equivalent to 20-speed Derryleuer drive-trains, and for more mechanical efficiency, internals running in the oil bath.
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