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Gearbox Bicycle
A gearbox bicycle is a bicycle that uses a gearbox to convert torque and rotational speed from the power source, usually the rider's legs, to what is desired at the drive wheel. The gearbox is usually incorporated into the frame near the crank, and it may be used in addition to or instead of derailleur gears or a hub gear. Cited advantages include improved shifting performance, protecting the gearing from damage and exposure to dirt and moisture, as with hub gears, plus locating the additional mass between the two wheels and on the frame where it may be suspended, unlike with hub gears. History Patents for built-in systems to change gear ratios appeared as early as 1890. Adler offered a three-speed gearbox bicycle in the 1930s. Several attempts to develop gearbox bicycles during the 2000s for downhill racing, such as the Honda RN-01 G-cross, incorporated complete derailleur gear drive trains in an enclosure. Around the same time Schlumpf Innovations and Hammerschmidt of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Downhill Mountain Biking
Downhill mountain biking (DH) is a style of mountain biking practiced on steep, rough terrain that often features jumps, drops, rock gardens and other obstacles. Jumps can be up to and including , and drops can be greater than . The rider commonly travels to the point of descent a ski lift or automobile, since the weight of the downhill mountain bike often precludes any serious climbing. In this context, the use of a motorized vehicle or device does not make DH a motorized sport. Riders must possess a unique combination of total body strength, aerobic and anaerobic fitness, and the acceptance of a relatively high risk of incurring serious permanent injuries. Downhill bikes are heavier and stronger than other mountain bikes and feature front and rear suspension with over 8 inches (20 cm) of travel, to glide quickly over rocks and tree roots. In competitive races, a continuous course is defined on each side by a strip of tape. Depending on the format, riders have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycle Types
Cycle, cycles, or cyclic may refer to: Anthropology and social sciences * Cyclic history, a theory of history * Cyclical theory, a theory of American political history associated with Arthur Schlesinger, Sr. * Social cycle, various cycles in social sciences ** Business cycle, the downward and upward movement of gross domestic product (GDP) around its ostensible, long-term growth trend Arts, entertainment, and media Films * ''Cycle'' (2008 film), a Malayalam film * ''Cycle'' (2017 film), a Marathi film Literature * ''Cycle'' (magazine), an American motorcycling enthusiast magazine * Literary cycle, a group of stories focused on common figures Music Musical terminology * Cycle (music), a set of musical pieces that belong together **Cyclic form, a technique of construction involving multiple sections or movements **Interval cycle, a collection of pitch classes generated from a sequence of the same interval class **Song cycle, individually complete songs designed to be performe ... [...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 coll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derailleur Gears
Shimano 600 front derailleur (1980) A derailleur is a variable-ratio bicycle gearing system consisting of a chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another. Modern front and rear derailleurs typically consist of a moveable chain-guide that is operated remotely by a Bowden cable attached to a shifter mounted on the down tube, handlebar stem, or handlebar. When a rider operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. Etymology ''Dérailleur'' is a French word, derived from the derailment of a train from its tracks. Its first recorded use was 1930. History A modern road bicycle drivetrain with front and rear derailleurs Various derailleur systems were designed and built in the late 19th century. One example is the Protean two-speed derailleur available on the Whippet safety bicycle. The French bicycle to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gear
A gear is a rotating circular machine part having cut teeth or, in the case of a cogwheel or gearwheel, inserted teeth (called ''cogs''), which mesh with another (compatible) toothed part to transmit (convert) torque and speed. The basic principle behind the operation of gears is analogous to the basic principle of levers. A gear may also be known informally as a cog. Geared devices can change the speed, torque, and direction of a power source. Gears of different sizes produce a change in torque, creating a mechanical advantage, through their ''gear ratio'', and thus may be considered a simple machine. The rotational speeds, and the torques, of two meshing gears differ in proportion to their diameters. The teeth on the two meshing gears all have the same shape. Two or more meshing gears, working in a sequence, are called a gear train or a '' transmission''. The gears in a transmission are analogous to the wheels in a crossed, belt pulley system. An advantage of gears is tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epicyclic Gearing
An epicyclic gear train (also known as a planetary gearset) consists of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates the planet and sun gears mesh so that their pitch circles roll without slip. A point on the pitch circle of the planet gear traces an epicycloid curve. In this simplified case, the sun gear is fixed and the planetary gear(s) roll around the sun gear. An epicyclic gear train can be assembled so the planet gear rolls on the inside of the pitch circle of a fixed, outer gear ring, or ring gear, sometimes called an ''annular gear''. In this case, the curve traced by a point on the pitch circle of the planet is a hypocycloid. The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a ''planetary gear train''.J. J. Uicker, G. R. Pennock and J. E. Shigley, 2003, ''Theory of Machines and Mechanisms,'' Oxford University Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schlumpf Drive
A Schlumpf Drive is a two-speed planetary gear assembly for use on bicycles and unicycles. It is distinct from other bicycle planetary gear assemblies in that it is located behind the chainring rather than in the rear hub. A push-button on each side of the axle allows the rider to switch between high and low ratios. These are operated by the rider's heel. Schlumpf Drives are primarily used as an alternative to multiple chainrings. Four models are currently produced, with differing ratios from pedal revolutions to chainwheel revolutions. *Speed Drive, this allows a 65% increase in the final drive (ratio 1.65). *High Speed Drive, this allows a 150% increase in the final drive (ratio 2.5). *Mountain Drive, this allows a 60% reduction in the final drive (ratio 0.4). *Reha Drive, this also allows a 60% reduction in the final drive (ratio 0.4). However, it is specifically designed for hand-cranked disability vehicles and requires less pressure for shifting. Schlumpf drives are curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honda RN-01 G-cross
The Honda RN-01 G-Cross is a mountain bike produced by Honda specifically for downhill racing events. Honda is not a manufacturer of bicycles and this bike is not commercially available to the general public. It was introduced in the 2004 racing season by the ''Team G Cross Honda'' who competed in the NORBA and Mountain Bike World Cup points series races. What sets it apart from most other bicycles is the fact that it was developed specifically for race use by the Honda team using many purpose made components not commercially available. It is also different in that it uses an internal gearbox instead of external (derailleur) gearing system, which although not unique to this bicycle, is quite rare. The gearbox on the RN-01 is specific because it is not a classic gearbox such as the Rohloff Speedhub, for example. Inside the gearbox there is a classic derailleur, a cassette and a chainring. The freewheel is not placed on the rear wheel but in the bottom bracket, so the chain is const ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adler (automobile)
Adler was a German automobile and motorcycle manufacturer from 1900 until 1957. The'' 'Adler' '' name is German for 'eagle'. History The Adler factory produced bicycles, typewriters, motorcycles and calculators in addition to cars. Before World War I, the company used De Dion two- and four-cylinder engines in cars that ranged from 1032 cc to 9081 cc; beginning in 1902 (the year Edmund Rumpler became technical director), they used their own engines as well. These cars, driven by Erwin Kleyer and Otto Kleyer (sons of the company founder Heinrich Kleyer) and by Alfred Theves won many sporting events. In the 1920s, Karl Irion raced many Adlers; popular models of the period included the 2298 cc, 1550 cc, and 4700 cc four-cylinders and the 2580 cc six-cylinders. A few of the Standard models, built between 1927 and 1934, featured Gropius-designed coachwork. The Adler Standard 6, which entered volume production in 1927, had a 2540 cc or 2916 cc six-cylinder engine, while the Adler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
