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Stringbike
A string-driven bicycle or stringbike is a bicycle that uses an external chainless rope and pulley drive system instead of a traditional bicycle chain and sprockets. The mechanism was commercialized by Hungarian Stringbike Kft which presented models in 2010 with a 19-speed system with no duplicate gears and having a 350% gear range. Design The mechanism has a rocker arm on each side of the bike that replaces the round sprockets (which are usually only on the right side) on chain driven bikes. In contrast to traditional derailleur chain drives, the drive does not slip when changing gears, and the gearing can be changed even when the bicycle is almost stationary. (similarly to a hub gear), but also "at full throttle." Two Dyneema ropes (ultra-high-molecular-weight polyethylene, UHMWPE) attached to pulleys attached to swinging lever and cam mechanisms have been used, one on each side of the bike. History In the 1990s, string-driven bicycles were developed by Mihály Lantos and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Drivetrain Systems
Bicycle drivetrain systems are used to transmit power on bicycles, tricycles, quadracycles, unicycles, or other human-powered vehicles from the riders to the drive wheels. Most also include some type of a mechanism to convert speed and torque via gear ratios. History The history of bicycle drivetrain systems is closely linked to the history of the bicycle. Major changes in bicycle form have often been initiated or accompanied by advances in drivetrain systems. Several early drivetrains used straight-cut gears that meshed directly with each other outside of the hub. Some bicycles have used a double-sided rear wheel, with different-sized sprockets on each side. To change gears, the rider would stop and dismount, remove the rear wheel and reinstall it in the reverse direction. Derailleur systems were first developed in the late 19th century, but the modern cable-operated parallelogram derailleur was invented in the 1950s. * Draisine * Penny-farthing * Safety bicycle Power colle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle
A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered transport, human-powered or motorized bicycle, motor-assisted, bicycle pedal, pedal-driven, single-track vehicle, with two bicycle wheel, wheels attached to a bicycle frame, frame, one behind the other. A is called a cyclist, or bicyclist. Bicycles were introduced in the 19th century in Europe. By the early 21st century there were more than 1 billion bicycles. There are many more bicycles than cars. Bicycles are the principal Mode of transport, means of transport in many regions. They also provide a popular form of recreation, and have been adapted for use as Toy, children's toys. Bicycles are used for Physical fitness, fitness, Military bicycle, military and Police bicycle, police applications, Bicycle messenger, courier services, Cycle sport, bicycle racing, and artistic cycling. The basic shape and configuration of a typical Safety bicycle, upright or "safety" bicycle, has changed lit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulley
Sheave without a rope A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft. A pulley may have a groove or grooves between flanges around its circumference to locate the cable or belt. The drive element of a pulley system can be a rope, cable, belt, or chain. History The earliest evidence of pulleys dates back to Ancient Egypt in the Twelfth Dynasty (1991–1802 BC) and Mesopotamia in the early 2nd millennium BC. In Roman Egypt, Hero of Alexandria (c. 10–70 AD) identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another. Plutarch's ''Parallel Lives'' recounts a scene where Archimedes proved the effectiveness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Chain
A bicycle chain is a roller chain that transfers power (physics), power from the Bicycle pedal, pedals to the Drive wheel, drive-Bicycle wheel, wheel of a bicycle, thus propelling it. Most bicycle chains are made from carbon steel, plain carbon or alloy steel, but some are nickel electroplating, nickel-plated to prevent rust, or simply for aesthetics. History Obsolete chain designs previously used on bicycles included the bar-link chain, block chain, the skip-link chain, and the Simpson lever chain. The first chains were of a simple, bushing-less design. These had inherent reliability problems and a bit more friction (and mechanical efficiency losses) than modern chains. With these limitations in mind, the Nevoigt brothers, of the German Diamant (German bicycle company), Diamant Bicycle Company, designed the roller chain in 1898, which uses bushings. More recently, the "bushingless roller chain" design has superseded the bushed chain. This design incorporates the bearing surfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sprocket
A sprocket, sprocket-wheel or chainwheel is a profiled wheel A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machin ... with teeth that mesh with a chain, rack and pinion, rack or other perforated or indented material. The name 'sprocket' applies generally to any wheel upon which radial projections engage a chain passing over it. It is distinguished from a gear in that sprockets are never meshed together directly, and differs from a pulley in that sprockets have teeth and pulleys are smooth except for timing pulleys used with toothed belts. Sprockets are used in bicycles, motorcycles, continuous track, tracked vehicles, and other machinery either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc. Perhaps the most commo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hub Gear
A hub gear, internal-gear hub, internally geared hub or just gear hub is a gear ratio changing system commonly used on bicycles that is implemented with planetary or epicyclic gears. The gears and lubricants are sealed within the shell of the hub gear, in contrast with derailleur gears where the gears and mechanism are exposed to the elements. Changing the gear ratio was traditionally accomplished by a shift lever connected to the hub with a Bowden cable, and twist-grip style shifters have become common. Hub gear systems generally have a long and largely maintenance-free life though some are not suitable for high-stress use in competitions or hilly, off-road conditions. Many commuter or urban cycles such as European city bikes are now commonly fitted with 7-speed gear-hubs and 8-speed systems are becoming increasingly available. Older or less costly utility bicycles often use 3-speed gear-hubs, such as in bicycle sharing systems. Many folding bicycles use 3-speed gear-hubs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyneema
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene (HMPE), it has extremely long chains, with a molecular mass typically between 2 and 6 million amu. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless, tasteless, and nontoxic. It embodies all the characteristics of high-density polyethylene (HDPE) with the added traits of being resistant to concentrated acids and alkalis, as well as numerous organic solvents. It is highly resistant to corrosive chemicals except oxidizing acids; has extremely low moisture absorption and a very low coefficient of friction; is self-lubricating (see boundary lubrication); and is highly resistant to abrasion, in some forms being 15 times more resistant to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cam (mechanism)
A cam is a rotating or sliding piece in a linkage (mechanical), mechanical linkage used especially in transforming rotary motion into linear motion. It is often a part of a rotating wheel (e.g. an eccentric wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes a lever at one or more points on its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to a steam hammer, for example, or an Eccentric (mechanism), eccentric disc or other shape that produces a smooth reciprocating (back and forth) motion in the ''Cam follower, follower'', which is a lever making contact with the cam. A cam timer is similar, and these were widely used for electric machine control (an electromechanical timer in a washing machine being a common example) before the advent of inexpensive electronics, microcontrollers, integrated circuits, programmable logic controllers and digital control. Camshaft The cam can be seen as a device that converts rotational mot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Padua
Padua ( ) is a city and ''comune'' (municipality) in Veneto, northern Italy, and the capital of the province of Padua. The city lies on the banks of the river Bacchiglione, west of Venice and southeast of Vicenza, and has a population of 207,694 as of 2025. It is also the economic and communications hub of the area. Padua is sometimes included, with Venice and Treviso, in the Padua-Treviso-Venice Metropolitan Area (PATREVE) which has a population of around 2,600,000. Besides the Bacchiglione, the Brenta River, which once ran through the city, still touches the northern districts. Its agricultural setting is the Venetian Plain. To the city's south west lies the Euganean Hills, Euganaean Hills, which feature in poems by Lucan, Martial, Petrarch, Ugo Foscolo, and Percy Bysshe Shelley. Padua has two UNESCO World Heritage List entries: its Botanical Garden of Padua, Botanical Garden, which is the world's oldest, and its 14th-century frescoes, situated in Padua's fourteenth-centu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land border, as well as List of islands of Italy, nearly 800 islands, notably Sicily and Sardinia. Italy shares land borders with France to the west; Switzerland and Austria to the north; Slovenia to the east; and the two enclaves of Vatican City and San Marino. It is the List of European countries by area, tenth-largest country in Europe by area, covering , and the third-most populous member state of the European Union, with nearly 59 million inhabitants. Italy's capital and List of cities in Italy, largest city is Rome; other major cities include Milan, Naples, Turin, Palermo, Bologna, Florence, Genoa, and Venice. The history of Italy goes back to numerous List of ancient peoples of Italy, Italic peoples—notably including the ancient Romans, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferenc Szőnyi
Ferenc Szőnyi (born 25 August 1964, in Komárom) is a Hungarian ultra-triathlete and ultra-runner. At the age of 40, he took up the triathlon and soon realized that he could excel as runner and triathlete in longer distances. He finished at 4th place in his first double Ironman race, in Bonyhád, Hungary, in 2008, after which he participated in several extreme distance events, like the Vienna–Bratislava–Budapest Supermarathon in his home country and in the Deca-Ironman, which consists of 38 kilometers of swimming, 1800 kilometers of cycling and 422 kilometers of running, and even the Double Deca-Ironman, both held in Monterrey, Mexico. In 2018, he won the Decaman ultratriathlon in New Orleans and by the president of Hungary he was bestowed Knight of the Order of Merit of the Hungarian Republic (Civilian). Main achievements In Mexico in 2009 Szőnyi set the new world record for the 10xIronman race with 115hrs time. During this race the participants completed one full d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
