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Cadence (cycling)
In cycling, cadence is a measure of rotational speed of the crank, expressed in units of revolutions per minute (r/min or rpm). In other words, it is the pedalling rate at which a cyclist is turning the pedals. Cadence is directly proportional to wheel speed, but is a distinct measurement and changes with gearing. In other words, the gearing changes the ratio of the crank's rotational speed (cadence) to that of the drive wheel's rotational speed. Typical cadence Cyclists typically have a cadence at which they feel most comfortable, and on bicycles with many gears it is possible to maintain a preferred cadence at a wide range of speeds. * 60–80 r/min is a typical cadence for many recreational and utility cyclists * According to cadence measurement of seven professional cyclists during three-week races they cycle about 90 r/min during flat and long (≈190 km) group stages and individual time trials of ≈50 km. During ≈15 km uphill cycling on hi ... [...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] |
Cycling
Cycling, also known as bicycling or biking, is the activity of riding a bicycle or other types of pedal-driven human-powered vehicles such as balance bikes, unicycles, tricycles, and quadricycles. Cycling is practised around the world for purposes including transport, recreation, exercise, and competitive sport. History Cycling became popularized in Europe and North America in the latter part and especially the last decade of the 19th century. Today, over 50 percent of the human population knows how to ride a bike. War The bicycle has been used as a method of reconnaissance as well as transporting soldiers and supplies to combat zones. In this it has taken over many of the functions of horses in warfare. In the Second Boer War, both sides used bicycles for scouting. In World War I, France, Germany, Australia and New Zealand used bicycles to move troops. In its 1937 invasion of China, Japan employed some 50,000 bicycle troops, and similar forces were instrumental in ... [...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
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 bicyc ... [...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] |
Tachometer
A tachometer (revolution-counter, tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a axle, shaft or disk, as in a motor or other machine. The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are increasingly common. The word comes . Essentially the words tachometer and speedometer have identical meaning: a device that measures speed. It is by arbitrary convention that in the automotive world one is used for engine revolutions and the other for vehicle speed. In formal engineering nomenclature, more precise terms are used to distinguish the two. History The first tachometer was described by Bryan Donkin in a paper to the Royal Society of Arts in 1810 for which he was awarded the Gold medal of the society. This consisted of a bowl of mercury constructed in such a way that centrifugal force caused the level in a central tube to fall when it rotated and brought down the level in a narrower t ... [...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] |
Cyclocomputer
A cyclocomputer, cycle computer, cycling computer or cyclometer is a device mounted on a bicycle that calculates and displays trip information, similar to the instruments in the dashboard of a car. The computer with display, or ''head unit'', usually is attached to the handlebar for easy viewing. Some GPS watches can also be used as display. History In 1895, Curtis H. Veeder invented the ''Cyclometer''. The Cyclometer was a simple mechanical device that counted the number of rotations of a bicycle wheel. A cable transmitted the number of rotations of the wheel to an analog odometer visible to the rider, which converted the wheel rotations into the number of miles traveled according to a predetermined formula. After founding the Veeder Manufacturing Company, Veeder promoted the Cyclometer with the slogan, ''It's Nice to Know How Far You Go''. The ''Cyclometers success led to many other competing types of mechanical computing devices. Eventually, cyclometers were develope ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycling Power Meter
A cycling power meter is a device on a bicycle that measures the Power (physics), power output of the rider. Most cycling power meters use strain gauges to measure torque applied, and when combined with angular velocity, calculate power. The technology was adapted to cycling in the late 1980s and was tested in professional bicycle racing i.e.: the prototype Power Pacer (Team Strawberry) and by Greg LeMond with the Schoberer Rad Meßtechnik, SRM device. This type of power meter has been commercially available since 1989. Training using a power meter is increasingly popular. Power meters generally transmit data wirelessly and can be paired to a Cyclocomputer, bike computer, smartphone, or smartwatch. By providing instantaneous feedback to the athlete, and by allowing more precise analysis of rides, power meters can be a useful tool for training. Interfaces Older cycling power meters use a set of wires to transmit power information to a computer mounted on the bicycle; this syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reed Switch
The reed switch is an Electromechanics, electromechanical switch operated by an applied magnetic field. It was invented in 1922 by professor Valentin Kovalenkov at the Peter the Great St. Petersburg Polytechnic University#Soviet era, Petrograd Electrotechnical University, and later evolved at Bell Labs, Bell Telephone Laboratories in 1936 by Walter B. Ellwood into the reed relay. In its simplest and most common form, it consists of a pair of Ferromagnetism, ferromagnetic flexible metal Electrical contacts, contacts in a hermetic seal, hermetically sealed glass envelope. The contacts are usually normally open, closing when a magnetic field is present, or they may be normally closed and open when a magnetic field is applied. The switch may be actuated by an electromagnetic coil, making a reed relay, or by bringing a permanent magnet near it. When the magnetic field is removed, the contacts in the reed switch return to their original position. The "reed" is the metal part inside t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Individual Time Trial
An individual time trial (ITT) is a road bicycle race in which cyclists race alone against the clock (in French: ''contre la montre'' – literally "against the watch", in Italian: ''tappa a cronometro'' "stopwatch stage"). There are also track-based time trials where riders compete in velodromes, and team time trials (TTT). ITTs are also referred to as "the race of truth", as winning depends only on each rider's strength and endurance, and not on help provided by teammates and others riding ahead and creating a slipstream. Individual time trials are usually held on flat or rolling terrain, although sometimes they are held up a mountain road (in Italian: ''cronoscalata'' "chrono climbing"). Sometimes the opening stage of a stage race is a very short individual time trial called a prologue (8 km or less for men, 4 km or less for women and juniors). Starting times are at equal intervals, usually one or two minutes apart. The starting sequence is usually based on the finishing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
