Sprocket 883953 224917749 2008-07-11T00:11:22Z ClueBot 4928500 Reverting possible vandalism by [[Special:Contributions/60.50.173.12|60.50.173.12]] to version by Savethemooses. False positive? [[User:ClueBot/FalsePositives|Report it]]. Thanks, [[User:ClueBot]]. (437385) (Bot) {{Unreferenced|date=November 2006}} {{Otheruses4|a gear or wheel with metal teeth|the television comedy sketch|Sprockets (television)}} [[Image:Sprocket16.png|thumb|16T type sprocket<br /> Do: Sprocket diameter<br /> Dp: Pitch diameter]] [[Image:Chain.gif|thumb|A sprocket and [[roller chain]]]] A '''sprocket''' is a profiled [[wheel]] with teeth that meshes with a [[roller chain|chain]], [[Caterpillar track|track]] or other perforated or indented material. It is distinguished from a [[gear]] in that sprockets are never meshed together directly, and from a [[pulley]] by not usually having a flange at each side. Sprockets are used in [[bicycle]]s, [[motorcycle]]s, [[automobile|cars]], [[tank]]s, and other [[machine]]ry either to transmit rotary motion between two shafts where gears are unsuitable or to impart linear motion to a track, tape etc. ==Cycles== In the case of bicycle chains, it is possible to modify the overall [[gear ratio]] of the chain drive by varying the diameter (and therefore, the tooth count) of the sprockets on each side of the [[Bicycle chain|chain]]. This is the basis of [[Derailleur gears]]. A 10-speed bicycle, by providing two different - sized driving sprockets and five different-sized driven sprockets, allows up to ten different gear ratios. The resulting lower gear ratios make the bike easier to pedal up hills while the higher gear ratios make the bike faster to pedal on flat roads. In a similar way, manually changing the sprockets on a motorcycle can change the characteristics of [[acceleration]] and top [[speed]] by modifying the final drive [[gear ratio]]. ==Tracked vehicles== [[Image:Leclerc p1040882.jpg|thumb|150px|A tank sprocket]] In the case of vehicles with [[caterpillar tracks]] the engine-driven toothed-wheel transmitting motion to the tracks is known as the ''drive sprocket'' and may be positioned at the front or back of the vehicle, or in some cases, both. ==Film and paper== Sprockets are used in the film transport mechanisms of [[movie projector]]s and [[movie camera]]s. In this case, the sprocket wheels engage [[film perforations]] in the [[film]] stock. Sprocket feed was also used for [[punched tape]] and is used for [[paper]] feed to some [[computer printer]]s. == See also == * [[Toothed belt]] <br> {{Gears}} [[Category:Bicycle parts]] [[Category:Gears]] [[Category:Power transmission]] [[Category:Mechanical_power_control]] [[de:Ritzel]] [[fr:Pignon (mécanique)]] [[ja:スプロケット]]