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Bicycle Performance
A bicycle's performance is extraordinarily efficient. 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. In terms of the ratio of cargo weight a bicycle can carry to total weight, it is also the most efficient means of cargo transportation. Mechanical efficiency From a mechanical viewpoint, up to 99% of the 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), 4–12% (chain with 3-speed hubs), or 10–20% (shaft drive with 3-speed hubs). The higher efficiencies in each range are achieved at higher power levels and in direct drive (hub gears) or with large driven cogs (derailleurs). Energy efficiency A human traveling on a bicycle at , using only the power required to walk, is the most energy-effic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watt
The watt (symbol: W) is the unit of power or radiant flux in the International System of Units (SI), equal to 1 joule per second or 1 kg⋅m2⋅s−3. It is used to quantify the rate of energy transfer. The watt is named after James Watt (1736–1819), an 18th-century Scottish inventor, mechanical engineer, and chemist who improved the Newcomen engine with his own steam engine in 1776. Watt's invention was fundamental for the Industrial Revolution. Overview When an object's velocity is held constant at one metre per second against a constant opposing force of one newton, the rate at which work is done is one watt. : \mathrm In terms of electromagnetism, one watt is the rate at which electrical work is performed when a current of one ampere (A) flows across an electrical potential difference of one volt (V), meaning the watt is equivalent to the volt-ampere (the latter unit, however, is used for a different quantity from the real power of an electrical circuit). : ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Team Time Trial
A team time trial (TTT) is a road bicycle race in which teams of cyclists race against the clock (see individual time trial for a more detailed description of ITT events). The winning team in a TTT is determined by the comparing the times of (usually) the fourth-finishing rider in each team (though the relevant finish position can be otherwise specified in advance by the race organisers). This means that each team will try to get their first four (at least) riders across the finish line in a tight group: it is actually a disadvantage for any rider to finish far in advance of the fourth rider, as by staying back a faster rider can help the fourth rider to get a quicker time. Where a TTT is part of a stage race, it is necessary for each rider to be given a finish time that can be cumulated into the general classification timings. Hence, all riders in the team who finish in the leading bunch are given the time of the fourth rider, and any rider who has been dropped is timed indiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peloton
In a road bicycle race, the peloton (from French, originally meaning 'platoon') is the main group or pack of riders. Riders in a group save energy by riding close ( drafting or slipstreaming) to (particularly behind) other riders. The reduction in drag is dramatic; riding in the middle of a well-developed group, drag can be reduced to as little as 5%–10%. Exploitation of this potential energy saving leads to complex cooperative and competitive interactions between riders and teams in race tactics. The term is also used to refer to the community of professional cyclists in general. Definition More formally, a peloton is defined as "two or more cyclists riding in sufficiently close proximity to be located either in one of two basic positions: (1) behind cyclists in zones of reduced air pressure, referred to as ‘drafting’, or (2) in non-drafting positions where air pressure is highest. Cyclists in drafting zones expend less energy than in front positions." A peloton has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycling In Copenhagen
Cycling in Copenhagen is – as with most cycling in Denmark – an important mode of transportation and a dominating feature of the cityscape, often noticed by visitors. The city offers a variety of favourable cycling conditions — dense urban proximities, short distances and flat terrain — along with an extensive and well-designed system of cycle tracks. This has earned it a reputation as one of the most bicycle-friendly cities in the world. Every day 1.2 million kilometres (0.75 million miles) are cycled in Copenhagen, with 62% of all citizens commuting to work, school, or university by bicycle; in fact, almost as many people commute by bicycle in greater Copenhagen as do those cycle to work in the entire United States. Cycling is generally perceived as a healthier, more environmentally friendly, cheaper, and often quicker way to get around town than by using an automobile. History Bicycles became common in Copenhagen at the beginning of the twentieth century. The ci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roadster (bicycle)
A roadster bicycle is a type of utility bicycle once common worldwide, and still common in Asia, Africa, Latin America, and some parts of Europe. During the past few decades, traditionally styled roadster bicycles have regained popularity in the Western world, particularly as a lifestyle or fashion statement in an urban environment. Design and variants There were three basic variants of the roadster. Roadster Gents' roadster The classic gents' roadster, AKA the English roadster, has a lugged brazed steel diamond frame, rod-actuated brakes and of late, cable operated drum brake systems have been widely produced for the European market, upright North Road handlebars, a single gear ratio or three- or five-speed hub gears, a chaincase, steel mudguards, steel cranks, (ISO 635) wheels, Westwood rims, and often a Sturmey-Archer hub dynamo. Roadsters are built for durability above all else and no serious attempt is made to save weight in their design or construction, roadsters ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Of Bicycle Speed
Graph may refer to: Mathematics *Graph (discrete mathematics), a structure made of vertices and edges **Graph theory, the study of such graphs and their properties * Graph (topology), a topological space resembling a graph in the sense of discrete mathematics * Graph of a function * Graph of a relation * Graph paper * Chart, a means of representing data (also called a graph) Computing * Graph (abstract data type), an abstract data type representing relations or connections * graph (Unix), Unix command-line utility *Conceptual graph, a model for knowledge representation and reasoning Other uses * HMS ''Graph'', a submarine of the UK Royal Navy See also *Complex network *Graf *Graff (other) *Graph database *Grapheme, in linguistics *Graphemics *Graphic (other) *-graphy (suffix from the Greek for "describe," "write" or "draw") *List of information graphics software This is a list of software to create any kind of information graphics: * either includes the abil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle
Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of muscle tissue, and are often known as muscle fibers. The muscle tissue of a skeletal muscle is striated – having a striped appearance due to the arrangement of the sarcomeres. Skeletal muscles are voluntary muscles under the control of the somatic nervous system. The other types of muscle are cardiac muscle which is also striated and smooth muscle which is non-striated; both of these types of muscle tissue are classified as involuntary, or, under the control of the autonomic nervous system. A skeletal muscle contains multiple fascicles – bundles of muscle fibers. Each individual fiber, and each muscle is surrounded by a type of connective tissue layer of fascia. Muscle fibers are formed from the fusion of developmental myoblasts in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resting Metabolic Rate
Resting metabolic rate (RMR) is whole-body mammal (and other vertebrate) metabolism during a time period of strict and steady ''resting conditions'' that are defined by a combination of assumptions of physiological homeostasis and biological equilibrium. RMR differs from basal metabolic rate (BMR) because BMR measurements must meet total physiological equilibrium whereas RMR conditions of measurement can be altered and defined by the contextual limitations. Therefore, BMR is measured in the elusive "perfect" steady state, whereas RMR measurement is more accessible and thus, represents most, if not all measurements or estimates of daily energy expenditure. Indirect calorimetry is the study or clinical use of the relationship between respirometry and bioenergetics, where the measurement of the rates of oxygen consumption, sometimes carbon dioxide production, and less often urea production is transformed to rates of energy expenditure, expressed as the ratio between ''i) energy'' an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal Metabolic Rate
Basal metabolic rate (BMR) is the rate of food energy, energy expenditure per unit time by endotherm, endothermic animals at rest. It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg body mass J/(h·kg). Proper measurement requires a strict set of criteria to be met. These criteria include being in a physically and psychologically undisturbed state and being in a Thermal neutral zone, thermally neutral environment while in the post-absorptive state (i.e., not actively digesting food). In Bradymetabolism, bradymetabolic animals, such as fish and reptiles, the equivalent term standard metabolic rate (SMR) applies. It follows the same criteria as BMR, but requires the documentation of the temperature at which the metabolic rate was measured. This makes BMR a variant of standard metabolic rate measurement that excludes the temperature data, a practice that has led to problems in defining "standard" rates of metabolism for ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joules
The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applied. It is also the energy dissipated as heat when an electric current of one ampere passes through a resistance of one ohm for one second. It is named after the English physicist James Prescott Joule (1818–1889). Definition In terms of SI base units and in terms of SI derived units with special names, the joule is defined as One joule can also be defined by any of the following: * The work required to move an electric charge of one coulomb through an electrical potential difference of one volt, or one coulomb-volt (C⋅V). This relationship can be used to define the volt. * The work required to produce one watt of power for one second, or one watt-second (W⋅s) (compare kilowatt-hour, which is 3.6 megajoules). This relationship can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kilocalorie
The calorie is a unit of energy. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of one kilogram of water by one degree Celsius (or one kelvin). The small calorie or gram calorie was defined as the amount of heat needed to cause the same increase in one gram of water. Thus, 1 large calorie is equal to 1000 small calories. In nutrition and food science, the term ''calorie'' and the symbol ''cal'' almost always refers to the large unit. It is generally used in publications and package labels to express the energy value of foods in per serving or per weight, recommended dietary caloric intake, metabolic rates, etc. Some authors recommend the spelling ''Calorie'' and the symbol ''Cal'' (both with a capital C) to avoid confusion; however, this convention is often ignored. In physics and chemistry the word ''calorie'' and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
