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A single-speed bicycle is a type of bicycle with a single gear ratio and a freewheel mechanism. These bicycles are without derailleur gears, hub gearing or other methods for varying the gear ratio of the bicycle. Adult single-speed bicycles typically have a gear ratio of between 55 and 75 gear inches, depending on the rider and the anticipated ...
The angular speed is inversely proportional to size, so the larger the one wheel, the less angular velocity, and vice versa. Actual pulley speeds tend to be 0.5–1% less than generally calculated because of belt slip and stretch. In timing belts, the inverse ratio teeth of the belt contributes to the exact measurement. The speed of the belt is:
A toothed belt, timing belt, cogged belt, cog belt, or synchronous belt is a flexible belt with teeth moulded onto its inner surface. Toothed belts are usually designed to run over matching toothed pulleys or sprockets. Toothed belts are used in a wide array of mechanical devices where high power transmission is desired.
Total face width is the actual dimension of a gear blank including the portion that exceeds the effective face width, or as in double helical gears where the total face width includes any distance or gap separating right hand and left hand helices. For a cylindrical gear, effective face width is the portion that contacts the mating teeth.
The 14-speed Rohloff Speedhub hub gear, introduced in 1998, has a range exceeding 5 to 1, and is thus comparable in range to 24, 27 and 30-speed derailleur systems (with 3×8, 3×9 and 3×10 cogs front and rear), since the latter have three overlapping ranges often with only about 14 distinct gears. As there is no overlap with the Speedhub, the ...
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This means the output shaft rotates at the same speed as the selected gear, thus determining the gear ratio of the transmission. [16] The dog clutch is a sliding selector mechanism that sits around the output shaft. It has teeth to fit into the splines on the shaft, forcing that shaft to rotate at the same speed as the gear hub. However, the ...
The gear mechanism was previously considered exclusively artificial, but as early as 1957, gears had been recognized in the hind legs of various species of planthoppers [61] and scientists from the University of Cambridge characterized their functional significance in 2013 by doing high-speed photography of the nymphs of Issus coleoptratus at ...