As time went on, the Bicycle Glossary has grown, and many of the pages became inconveniently large.
I have split the larger pages into smaller ones, but I realize that there may be external links pointing to the older pages. For this reason, I have maintained copies of the older pages at the same location.
This is one of the older pages, and the newer pages that were derived from it are liable to be more complete and up to date, so please follow the links below to the current version. Sorry for any inconvenience.
If one of my own pages had a link that took you to this page, it would be helpful if you would send me an email with the URL of the page that had the bad link, so I can update it.
Sheldon Brown
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- Most modern bicycles use cables to control the gear shifting and brakes. These cables, also known as "Bowden cables" consist of two parts, an inner cable of twisted steel wire, and an outer cable housing. Cables transmit force by a combination of tension on the inner cable and compression to the housing.
In many installations the housing doesn't run along the full length of the cable, but transmits the compressive part of the load to the frame by means of housing stops, fittings with holes small enough for the cable, but not small enough for the housing to pass through. Some cable stops feature adjusting barrels.
This site features an extensive Article on Cable Installation.
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- A cable guide is a fitting or frame feature which guides a piece of bare inner cable around a corner. Most multi-speed bicycles have cable guides to get the derailer cables past the bottom bracket.
Older derailer bikes used either brazed-on or clamp-on guides just above the bottom bracket, but newer bicycles have a guide under the bottom bracket.
The below-the-bottom-bracket option has the advantage of being cheaper, and, for some bikes with very small chainweels, it eliminates interference betwixt the rear derailer cable and the bottom of the front derailer cage. It also makes it slightly easier to clean the frame cosmetically.
The above-the-bottom-bracket system is superior in that the cable is shorter and the loop of housing at the rear derailer is not as tight, since the cable stop is atop the chainstay, rather than beneath it.
Poor lubrication of bottom-bracket cable guides is a common cause of autoshifting.
Some bicycles use a cable guide on one side of the seat cluster for a rear cantilever brake cable, rather than use a short length of housing between two housing stops.
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- A fitting found at each end of a piece of cable housing. It consists of a socket to receive the housing, with a small hole at the bottom, which will let the inner cable slide through, but hold the housing end rigidly in place.
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- The speed at which the pedals turn, measured in Revolutions Per Minute. Inexperienced cyclists tend to ride in higher gears than they should, pedaling at a slower cadence.
Most experienced cyclists pedal at cadences in the range of 70-90 RPM. This puts less strain on the joints, particularly the knees. Racing cyclists often use even higher cadences for bursts of accelleration.
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A metal or plastic holder for the bearing balls in a ball bearing. Use of a cage keeps the balls from bumping into one another, and allows the use of fewer balls. In the case of traditional cup-and-cone bearings used on bicycles, the primary purpose of caged balls is to save labor. More formally known as a retainer.
- A holder for carrying a water bottle.
- The part of a derailer through which the chain passes. The front derailer cage is a simple guide, the rear derailer cage contains the jockey pulley and the tension pulley.
- The outer part of a conventional pedal, the part that comes into contact with the rider's shoe.
- The part of an internal gear hub which holds the planet pinions.
- Slang term for an automobile; a "cager" is the driver of an automobile.
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- A caliper is a measuring device with moving parts that come together to determine the dimensions of a part.
Most bicycle brakes use a similar mechanism to move the brake shoes inward toward the rim, so they are called caliper brakes. A caliper brake uses a single assembly to move both brake shoes together, unlike a cantilever brake which has a separate unit on each side of the rim.
A brake caliper attaches to the bicycle by a single bolt, through the center of the fork crown or the brake bridge on the seat stays.
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- The rider of a tandem who is responsible for steering. This is usually the front rider. The captain is usually also responsible for controlling the gears and brakes. See also stoker.
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- A mechanical device for converting one kind of motion to another, usually rotary to linear. The main application for cams in bicycle technology is in quick-release mechanisms. As the quick-release lever is rotated from the open to the closed position, the cam built into the pivoting end of the handle applies a push to the quick-release mechanism housing, and a pull to the skewer.
Some internal gear hubs use cams to change the engagement of pawls, to select different gear ratios.
See also rollercam brake.
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- The leading Italian maker of bicycle parts. Campagnolo invented the quick release, and was instrumental in the development of the derailer.
Campagnolo parts are so highly regarded that Campagnolo's proprietary dimensions have, in several cases, become adopted as de facto international standards. This is particularly so in the case of headsets.
The Campagnolo headset dimensions are 26.4 mm for the fork crown race and 30.2mm for fitting the frame races into the head tube. Other common systems, such as J.I.S., use a larger diameter (such as 27 mm) for the steerer, and a smallaer diameter (30 mm) for the head tube. These frame/fork dimensions can be easily machined to fit Campagnolo style headsets.
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- A cantilever brake has two separate arms, or cantilevers, one on each side of the rim. Each arm has pivots on an independent boss, and the two arms are usually coordinated and linked by a transverse (or straddle or crossover) cable that runs above the top of the tire. The transverse cable is commonly connected to the main brake cable by a yoke. In some newer designs, the end of the main cable becomes half of the transverse cable, and a short link wire forms the other half. For details on cantilevers, see my article on Cantilever Geometry
A recent variation on cantilever brakes is the V brake which dispenses with the transverse cable altogether.
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- A frame style popular on cruisers, in which the seat curved stays pass by the seat cluster and continue on in a graceful
arch to join the bottom of the head tube.
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- Carbon filaments used with a resin, in a technology similar to fibreglass. The resulting composite material is very strong in the direction that the fibers run in. Carbon fiber is available in the form of tubing with a woven/braided weave, which can be glued into lugs to build more-or-less conventional frames. A more sophisticated approach is to lay up the carbon fiber cloth in a specific shape, in a mould the shape of the finished bicycle. This allows the orientation of the fibers to provide strength in the direction of the actual stress. Carbon fiber technology shows great promise, but there have been reliability problems with many early models.
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- Tire (Mainly british usage.)
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Bearings which are assembled in a modular unit, as opposed to cup-and-cone bearings, which may be disassembled down to the individual bearing balls for service.
Cartridge bearings are the only type of ball bearings used in most industrial products; bicycle technology is the major area where cup-and-cone bearings still survive, but they are in decline even in the bicycle industry.
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| A conventional cup-and-cone bottom bracket. The lock ring wrench is about to loosen the lockring, the pin wrench is engaging two of the holes in the adjustable cup |
| A cartridge bottom bracket. The splined tool is shown above the bottom bracket. The crank would need to be removed to actually use the tool.
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- A cluster of sprockets and spacers designed for use on a freehub. Some of the sprockets and spacers may be semi-permanently attached to one another by bolts or rivets. See my article on Shimano Cassettes
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- The forming of metal parts by pouring molten metal or other material into a mould. This is the cheapest way of making large quantities of parts that are of shapes that cannot be produced by stamping. The parts are not generally as stong as those that can be made by forging, and parts made in a re-usable mould cannot be of as complicated shape as is possible with CNC machining from billets, because some shapes cannot be removed from a mould without breaking it.
An exotic form of casting, called investment casting or "lost wax" casting permits casting of complicated shapes by using single-use plaster moulds that can be broken apart to free the cast part from the mould. This is an expensive process used mainly for high quality lugs and fork crowns.
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- A caliper brake in which the main cable runs down the center line of the bicycle, using a yoke to connect to a transverse cable. Technically, a normal cantilever brake is a form of center-pull brake, but the term is normally used to refer to caliper brakes only. This type of brake was popular from the late 1960's to the early 1980's, but is currently out of fashion. Center-pull brakes are a good choice for bicycles that have a long reach from the mounting point to the rim.
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- 100 miles (161km). A "metric century" is 100 km (62 miles.)
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- Modern bicycles use roller chain to connect the cranks to the rear wheel. Chain drives are among the most efficient means of power transmission known.
Chain size is specified by pitch and width. The pitch is the distance between rollers (1/2" on all modern bicycle chain). The width is the internal width where the sprocket teeth fit in.
Bicycle chain comes in two basic widths:
- 1/8" chain is used on most single-speed bicycles, and bicycles with internal gearing.
- 3/32" chain is used on derailer equipped bicycles that have more than 3 speeds.
Chains for derailer applications also come in various external widths. Newer clusters which have more sprockets use chain with thinner side plates and flush rivets.
For more information on chains, see my article on Chain Maintenance.
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- Gear case
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- This refers to how straight the chain runs between the front and rear sprockets. Ideally, both sprockets should be in the same plane, so that there is no sideward motion or stress to the chain. This constitutes "perfect chainline".
In the case of derailer geared bicycles, the chainline is not perfect in most gears. The worse the chainline, the worse the mechanical efficienty of the drive train.******
"Correct" chainline for a derailer system is a matter of opinion, and depends on the intended use of the bicycle. There are two "simple" answers to the question of what constitutes proper chainline:
- One view is that the middle of the cluster should line up with the middle chainring (or half-way between the two, in the case of a double.
- From the manu*****
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- A front sprocket, specifically of the type that would attach to the crank by being bolted on to a spider.
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- British term for "crank set"
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- The (usually tapered) tubes that run from the bottom bracket to the rear fork ends.
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- ******
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- Popular term for a front sprocket.
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- An idler pulley used to adjust the tension of a tandem synch chain. This system is used on inexpensive tandems, as a cheap substitute for an eccentric bottom bracket.
- A device used on some one-speed bicycles to adjust the chain tension by pulling back on the rear axle with a screw thread. One popular type used on BMX bicycles is called a "banjo bolt"
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- Derailer. (Mainly British usage.)
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- Raleigh trademark for a family of wheelie bikes. These have become moderately valuable to collectors.
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- Chromium is a metal, which is used in two ways in bicycle technology:
- As an alloying element to steel, usually along with molybdenum or vanadium. It makes the steel tougher.
- As a plating for steel or brass, it has a shiny silver appearance, and provides some protection against rust.
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- Steel that has been alloyed with small amounts of Chromium and Molybdenum. This is the material used for most high-quality bicycle frames and forks.
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- See adaptor claw.
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- *****
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- A leather, plastic or metal fitting attched to the bottom of a cycling shoe to provide positive engagement with the pedal.
- Classic cleats for use with toe-clip pedals had a simple slot that fitted over the rear edge of the pedal. This provided a consistent position of the foot on the pedal, both in terms of centering the ball of the foot over the pedal spindle, and maintaining the desired foot angle on the pedal.
Up until the late '70's, cleats were leather or alumium, and were nailed onto the bottom of the shoe with many tiny nails. The usual procedure was to have the cyclist ride for a while without the cleats, until the pedal would make a mark on the sole of the shoe. This mark would then be used as a guide to locate where the cleat should be nailed on.
In the '70's, adjustable plastic cleats were introduced, and immediately rendered the nail-on system obsolete...unfortunately, they also precipitated a rash of knee injuries, because riders would adjust them by pure guesswork, and this often caused un-natural stresses on their knees. The invention of the Fit-Kit R.A.D. made it possible to adjust this type of cleat even more accurately than the old sole-impression system.
- Cleats for clipless pedals are made of metal or plastic, and lock into the pedal mechanism. They are adjusted in the same manner as the adjustable cleats of the '70's.
Before the invention of clipless pedals, classic cleats were the only way to provide positive, accurate shoe/pedal attachment. They were rather dangerous, however. If the straps were overtightened, it could become impossible to get your foot out in an emergency, and many embarrasing falls have resulted from this. They also were slippery and hazardous to walk on.
Modern clipless pedals have solved these problems, and, in my opinion, nobody should still be using classic cleats. Now that there is an alternative, they are just not worth the risk.
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- This is the normal type of tire, with a separate inner tube. The tire consists of two hoops called "beads", made of steel or Kevlar cable, which are held together by cloth, usually nylon. The whole assembly is dipped in rubber, with thicker rubber applied in the tread area.
A clincher tire has a separate inner tube, which is basically a rubber balloon. This fits inside the tire, and the tire is mounted on the rim by lifting the beads over the edge of the rim. The middle of the rim makes a sort of valley, and while the tire is being installed, most of the bead can fit into this valley. This gives enought slack to allow the bead to be pushed or pulled over the edge of the rim, even though outside diameter of the rim is larger than the inside diameter of the bead.
Strictly speaking, the term "clincher" is slightly incorrect, as it applied to an obsolete style of tire which had ribs in the edges of the tire which fitted into grooves on the rim, where the tire was folded under the tube. The air pressure in the tube pressed the rib into the groove, and "clinched" the tire in place. People who are fussy about this prefer the term "wire-on."
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- "Clipless" or "Step-in" pedals use a mechanism similar to a ski binding. In fact the first successful system was made by a ski binding manufacturer, Look. Clipless pedals use a cleat which is bolted to the bottom of the shoe. When the rider steps on the pedal with the cleat, the cleat locks into the pedals mechanism, and is held firmly in place. Some systems hold the foot at a fixed angle, others allow various amounts of "float", or angular rotation of the foot on the pedal.
With most clipless pedal systems, the foot is disengaged by twisting the heel outward. Some of the earlier systems, such as the pioneering Cinelli model, required the rider to reach down and operate a release mechanism by hand. This style is sometimes jocularly referred to as "death cleats."
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- A group of rear sprockets on a multi-speed bicycle. If the bicycle uses a thread-on freewheel, the term "cluster" would include the entire assembly including the freewheel mechanism. In the case of a cassette hub, the "cluster" would only consist of the sprockets and the spacers that separate them.
See also seat cluster.
CLWB
- Compact Long Wheel Base
The following entries were moved when the "C" section was split:
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- Moved to CNC
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- Moved to Coaster
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- Moved to Cog.
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- Moved to Compact drive
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- Moved to Cone
Cone wrench
- Moved to gloss_cn-z.html
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- Moved to Cottered cranks
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- Moved to Crank
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- Moved to Crank set
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- Moved to gloss_cn-z.html
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- Moved to Criterium
Cross bicycle
- Moved to Cross
Cross frame
- Moved to Cross frame
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- Moved to Crossover
Crossover gearing
- Moved to gloss_cn-z.html
Crow's foot spoking
- Moved to gloss_cn-z.html
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- Moved to Crown
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- Moved to Cruiser
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- Moved to Cup-and-cone
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- Moved to Cyclecomputer
Cyclocross
- Moved to Cyclocross
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- Moved to Cyclometer
