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Gear Inches
Gear inches is one way of measuring the gear ratio(s) of a bicycle, so that different gears and different bicycles can be compared in a consistent manner. Gear inches is an imperial measure corresponding to the diameter in inches of the drive wheel of a penny-farthing bicycle with equivalent ( direct-drive) gearing. A commonly used metric alternative is known as metres of development or rollout distance, which specifies how many metres a bicycle travels per revolution of the crank. Typical gear ratios on bicycles range from very low or light gearing around 20 gear inches (1.6 metres per revolution), via medium gearing around 70 gear inches (5.6 m), to very high or heavy gearing around 125 gear inches (10 m). As in a car, low gearing is for going up hills and high gearing is for going fast. Origin of the term gear inches When the high wheeler or penny-farthing was the "ordinary" bicycle form, the comparative diameter in inches of the driven wheel was an indication of re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Mechanical Advantage Simplified En
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] |
Union Cycliste Internationale
The Union Cycliste Internationale (; UCI; ) is the world governing body for sports cycling and oversees international competitive cycling events. The UCI is based in Aigle, Switzerland. The UCI issues racing licenses to riders and enforces disciplinary rules, such as in matters of doping. The UCI also manages the classification of races and the points ranking system in various cycling disciplines including road and track cycling, mountain biking, cyclo-cross, Gravel, and BMX, for both men and women, amateur and professional. It also oversees the World Championships. After the 2022 Russian invasion of Ukraine, the UCI said that Russian and Belarusian teams were forbidden from competing in international events. It also stripped both Russia and Belarus of scheduled events. History The UCI was founded on 14 April 1900 in Paris by the national cycling sports organisations of Belgium, the United States, France, Italy, and Switzerland. It replaced the International Cycl ... [...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] |
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 Fren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Performance
Bicycle performance is measurable performance such as energy efficiency that affects how effective a bicycle is. Bicycles are extraordinarily efficient machines; in terms of the amount of energy a person must expend to travel a given distance, cycling is calculated to be the most efficient self-powered means of transportation. The transport performance of bicycles is also exceptional in terms of ton kilometers. In terms of the ratio of cargo weight ( payload) a bicycle can carry to the total bike weight, cycling (here under cargo biking) is also the most efficient means of cargo transportation. Mechanical efficiency From a mechanical viewpoint, up to 99% of the mechanical energy delivered by the rider into the pedals is transmitted to the wheels (clean, lubricated new chain at 400 W), although the use of gearing mechanisms reduces this by 1–7% (clean, well-lubricated derailleurs and a straight chainline), 4–12% (chain with 3-speed hubs), or 10–20% (shaft d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Gearing
Bicycle gearing is the aspect of a Bicycle drivetrain systems, bicycle drivetrain that determines the relation between the cadence (cycling), cadence, the rate at which the rider pedals, and the rate at which the drive Bicycle wheel, wheel turns. On some bicycles there is only one gear and, therefore, the gear ratio is Single-speed bicycle, fixed, but most modern bicycles have multiple gears and thus multiple gear ratios. A Shifter (bicycle part), shifting mechanism allows selection of the appropriate gear ratio for efficiency or comfort under the prevailing circumstances: for example, it may be comfortable to use a high gear when cycling downhill, a medium gear when cycling on a flat road, and a low gear when cycling uphill. Different gear ratios and gear ranges are appropriate for different people and styles of cycling. A cyclist's legs produce power optimally within a narrow pedalling speed range, or cadence. Gearing can be optimized to use this narrow range as efficiently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimensionless Quantity
Dimensionless quantities, or quantities of dimension one, are quantities implicitly defined in a manner that prevents their aggregation into unit of measurement, units of measurement. ISBN 978-92-822-2272-0. Typically expressed as ratios that align with another system, these quantities do not necessitate explicitly defined Unit of measurement, units. For instance, alcohol by volume (ABV) represents a volumetric ratio; its value remains independent of the specific Unit of volume, units of volume used, such as in milliliters per milliliter (mL/mL). The 1, number one is recognized as a dimensionless Base unit of measurement, base quantity. Radians serve as dimensionless units for Angle, angular measurements, derived from the universal ratio of 2π times the radius of a circle being equal to its circumference. Dimensionless quantities play a crucial role serving as parameters in differential equations in various technical disciplines. In calculus, concepts like the unitless ratios ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheldon Brown (bicycle Mechanic)
Sheldon Brown (July 14, 1944 – February 4, 2008) was an American bicycle bicycle mechanic, mechanic, technical expert and author. He contributed to print and online sources related to bicycling and bicycle mechanics, in particular the web site ''Sheldon Brown's Bicycle Technical Info''. His knowledge of bicycles was described as "encyclopaedic" by ''The Times'' of London. Background Brown was the parts manager, webmaster and technical consultant of Harris Cyclery, a local bike shop, bike shop in West Newton, Massachusetts, as well as an enthusiast of vintage and classic bicycles in addition to cycling in general. Brown maintained ''Sheldon Brown's Bicycle Technical Info'', a web site highlighting a broad range of cycling subjects ranging from how to fix a bicycle flat tire to details on Raleigh Bicycle Company, Raleigh and English three-speed bicycles, Sturmey-Archer hubs, tandem bicycle, tandems, and fixed-gear bicycles. He repaired cameras and was an Amateur Photographer, ama ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Advantage
Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. The device trades off input forces against movement to obtain a desired amplification in the output force. The model for this is the ''law of the lever.'' Machine components designed to manage forces and movement in this way are called mechanisms. An ideal mechanism transmits power without adding to or subtracting from it. This means the ideal machine does not include a power source, is frictionless, and is constructed from rigid bodies that do not deflect or wear. The performance of a real system relative to this ideal is expressed in terms of efficiency factors that take into account departures from the ideal. Levers The lever is a movable bar that pivots on a fulcrum attached to or positioned on or across a fixed point. The lever operates by applying forces at different distances from the fulcrum, or pivot. The location of the fulcrum deter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
German Cycling Federation
The German Cycling Federation or BDR (in German: ''Bund Deutscher Radfahrer'') is the national governing body of cycle racing in Germany. The BDR is a member of the UCI and the UEC. History The BDR was first created in 1884 in Leipzig, only to be subsequently dissolved in 1933 after the Enabling Act of 1933, which legally gave Hitler dictatorial control of Germany. The '' Deutscher Radfahrer-Verband'' (DRV), a unit (Fachamt) of the Nazi Sports Body took over, until it was disbanded on May 31, 1945, for being the branch of a Nazi organization. The BDR was re-established on 21 November 1948. In East Germany the cycling section of the Deutscher Sportausschuss, the DDR's sports body, was established in 1946. In 1957 it was renamed ''Deutscher Radsport-Verband der DDR'' (DRSV), "East German Cycling Federation", which was responsible for the sport until the merger of both countries on 7 December 1990. Since 2005, the president of the BDR has been former Federal Minister of Defe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micro Drive
Micro drive is a type of bicycle drivetrain, mostly BMX and MTB, that uses smaller than standard-sized sprockets. The smallest rear sprocket that fits on a freehub body is a 10 or 11-tooth, but with the use of a cassette hub, sometimes called a micro drive rear hub, sprockets as small as 8 teeth may be used. Some examples of micro drive hubs are Shimano Microspline (12-speed, 10-teeth) and SRAM XD/XDR (11/12-speed, 9-teeth or 10-teeth). Reduced weight and increased ground clearance The advantage of micro drive is that it means a smaller front sprocket, or chainring, can be used without affecting the gear ratio, providing better ground clearance. For example, a bike using a 32-tooth chainring with a 16-tooth rear sprocket can switch to using an 18-tooth chainring and a 9-tooth sprocket, and still have a 2:1 ratio. Another advantage is the reduction in weight with the reduction in size of all the parts. Increased wear and costs The disadvantage is increased stresses on the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle Gearing
Bicycle gearing is the aspect of a Bicycle drivetrain systems, bicycle drivetrain that determines the relation between the cadence (cycling), cadence, the rate at which the rider pedals, and the rate at which the drive Bicycle wheel, wheel turns. On some bicycles there is only one gear and, therefore, the gear ratio is Single-speed bicycle, fixed, but most modern bicycles have multiple gears and thus multiple gear ratios. A Shifter (bicycle part), shifting mechanism allows selection of the appropriate gear ratio for efficiency or comfort under the prevailing circumstances: for example, it may be comfortable to use a high gear when cycling downhill, a medium gear when cycling on a flat road, and a low gear when cycling uphill. Different gear ratios and gear ranges are appropriate for different people and styles of cycling. A cyclist's legs produce power optimally within a narrow pedalling speed range, or cadence. Gearing can be optimized to use this narrow range as efficiently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
