The "capacity" of a derailleur is the largest range of sprocket sizes it can handle. Different front derailleurs have different capacities depending on how tall their cages are, and it is expressed in a 'number of teeth' being the difference between the largest and smallest chainwheel. For instance, a tri-chainringed 52/42/30 crank set would call for a front derailleur with a minimum 22 tooth (52-30) capacity. Front derailleurs are also designed to be used with a certain size for the largest chain ring. The curvature of the outer cage plate is matched to this size. If you use a different size big ring, capacity may be reduced. If the big ring is substantially smaller than what the derailleur is designed for, shifting precision will suffer and you are likely to have to "trim" the front derailleur as you shift the rear derailleur to the extremes. ii) For rear derailleurs, the capacity relates to the amount of chain slack the derailleur can take up, and is equal to the front range (22 in the example above) plus the rear range. Thus, if you have a 52/42/30 crank set, and a 12-28 (16 tooth difference) cluster, the total capacity required would theoretically be 38 teeth (22 front difference + 16 rear difference).Derailleurs can considerably exceed the official capacity if they are not misused on the granny ring running on the smaller rear sprockets. Rear derailleurs are commonly designed for a maximum size rear sprocket. If you exceed this size by too much, the jockey pulley may rub against the sprocket when using the lowest gear. Derailleurs are relatively inexpensive and fairly easy to replace, and it is not necessary to allow the limitations of a particular derailleur to keep you from having the gearing appropriate to your riding style / comfortable cadence.

 Sheldon Brown

A French cycling term. The real reason many French attend the Tour. A parade of gaudy commercial floats staffed by attractive young people with bleached teeth and wide smiles who throw trinkets and souvenirs to the crowds. The Caravane precedes the riders by about 90 minutes and can take as long as an hour to pass. Promotional fees paid by the sponsors of Caravane vehicles are the primary source of revenue for the Tour organizers. In 2002, a young child was struck and killed by one of the vehicles in the Caravane when he ran into the road to gather up some trinkets.

Carbon filaments used with a resin in technology similar to fibreglass. The resulting composite material is very strong in the direction that the fibres run in. Carbon fibre 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 fibre cloth in a specific shape, in a mould the shape of the finished bicycle. This allows the orientation of the fibres to provide strength in the direction of the actual stress. Carbon fibre technology had reliability problems with many early models, but it would seem that thye've gotten it right - at a price!

The articulated drive unit connecting the chainwheel to the freewheel. Chain drives are among the most efficient means of power transmission known, and modern bicycles use a 'roller chain' to connect the cranks to the rear wheel. Chain size is specified by pitch and width. The pitch is the distance between rollers (1/2" on all modern bicycle chains). 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 derailleur equipped bicycles that have more than 3 speeds. Chains for derailleur applications also come in various external widths -newer clusters which have more sprockets use chain with thinner side plates and flush rivets. Older non derailleur chains are broken at the masterlink, whilst modern type chains can be broken at any point along their length.

In some triple chainring installations, typically when the "granny" gear is unusually small, it may be impossible to get good shifting to the "granny" chainring with the normal derailleur adjustments alone. A loose adjustment of the low-gear stop causes the chain to derail past the small chainring, but a tighter setting results in slow downshifting to the small ring. In such cases, a good - if inelegant - solution is sometimes to install a chain deflector, an anti-derailment device that clamps to the seat tube. These products, such as the 3rd Eye Chain Watcher ® and the N-Gear Jump Stop ® set up a barrier preventing the chain from overshooting the small ring, no matter how loose the low-gear stop is set. This allows the low-gear stop to be set to allow the derailleur to move farther inboard for faster, more precise shifting, even under some load. These devices can often save the day when extra-wide range gearing is used on a mountain bike or tandem.

Downhill device used to keep chain on a single chainwheel in rough terrain.

The action of a chainwheel that doesn’t release the chain at the beginning of its return cycle. Chain suck occurs primarily when downshifting under load from the middle to the smallest chainring. The bottom run of the chain may not immediately disengage from the middle ring, and can get carried upward until it wedges betwixt the chainwheels and the right chainstay which jams the crankset. Since you probably wouldn't have been shifting to the granny if you weren't already climbing, the sudden lock-up of the drive train deprives you of what little momentum you had, and you are very likely to stall. Chain suck is commonly caused by bent chainring teeth, dirty chains, or, occasionally, burrs on the teeth of new chainwheels.

A device / pulley used to adjust the chain tension when a bike with vertical dropouts is converted to use a singlespeed or internal gear drive train. Some of these use two pulleys, like a rear derailleur, that doesn't move from side to side.  An 'idler pulley' is used to adjust the tension of a synch chain 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".

Any of several types of protective baffle used to prevent the chain from entrapping a trouser leg, or soiling the cyclist's leg or clothing. Getting a trouser leg caught in the chain can be an inconvenience on any bicycle, but, in the case of a bicycle with a coaster brake or a fixed gear, it can be extremely dangerous. i) The traditional "hockey-stick" type chain guard extends from the seat stay forward and covers the upper run of chain, running down the front side of the chainwheel. The full gear case or chain case completely encloses the chain. This type of chain guard is quite popular in the Netherlands. ii) Chainwheel discs, unlike the above style of chain guard, are usable on bicycles with derailleur gearing and multiple chainwheels. They are primarily intended to prevent soiled clothing, since the front derailleur tends to keep trouser cuffs from being snagged. Unfortunately, many chainwheel discs interfere with obtaining the best possible front derailleur adjustment. Should the chain become derailed on a bike with a chainwheel disc, it may become seriously wedged between the disc and the large chainring. Chainwheel discs are rarely found on high quality bicycles.

This refers to how straight the chain runs between the front and rear sprockets. Ideally, both sprockets should be in the same plane, allowing no sideward motion or stress to the chain constituting a "perfect chainline". In the case of derailleur 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 derailleur 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 parts manufacturers' point of view, the chainline depends on the diameter of the seat tube where the front derailleur mounts. For fatter seat tubes where the front derailleur is farther to the right, derailleur manufacturers want the chainline to be farther to the right also, because their main priority is shifting performance, and their front derailleurs have an optimal chainline with respect to the edge of the seat tube. This is particularly a concern in the case of bicycles with indexed front shifting. From the rider's point of view, chainline is partly dependent on how you are going to use your gears. For instance, consider a road triple vs a mountainbike triple: With a road triple, you mostly use the two bigger rings, the granny is only occasionally used, and only with the larger rear sprockets. For a road triple, having the cranks close-in is good, because it increases the usability of the big ring. With a mountain bike, the small ring is used much more often, and must often be used with fairly small sprockets to avoid having to shift the front under load. For mountain bikes, a more 'outboard' chainwheel position is often preferable.

Chainline is measured from the centreline of the frame to the centre of the chain. You can measure the front chainline directly with a simple ruler. Simply hold the ruler against the seat tube or down tube and measure the distance to the middle of the chainring teeth. In the case of triple chainwheel sets, measure to the middle chainring. In the case of doubles, measure to the halfway point between the two rings. To measure rear chainline, the easiest way is to measure the distance from the inside of the rear fork end (or the outside of the axle locknut) to the middle of the sprocket. Double this, subtract it from the over-lock-nut dimension of the hub (or the frame spacing , which should be the same), then divide the result in half, and you have the rear chainline.

i) Raleigh trademark for a family of wheelie bikes moderately valuable to collectors. ii) During 2005 there was a fad for "retro choppers". These are not true wheelie bikes, but have styling similar to a "chopper" motorcycle. They'll generally feature extended forks with very slack angles and a very laid-back seat tube angle as well. The resulting riding position is midway between a conventional upright bike and a recumbent. Retro choppers usually have unusually wide rear tyres, and medium width front tyres. Choppers tend to be heavy, sluggish bikes, suitable for short leisurely rides in flat terrain. More for show than for actual riding.

A leather, plastic or metal fitting attached to the bottom of a cycling shoe to provide coupling 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 aluminum, 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. Cleats for clipless pedals are made of metal or plastic, lock into the pedal mechanism and often incorporate a float.

This is the "normal"/ usual type of tyre, with a separate inner tube. The tyre 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 tyre's inner tube / a rubber balloon fits inside the tyre, and the tyre is mounted on the rim by lifting the beads over the edge of the rim. The rim makes a valley, and while the tyre 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 perhaps incorrect, as it applies to an obsolete style of tyre which had ribs in the edges of the tyre which fitted into grooves on the rim, where the tyre was folded under the tube. But in both style of tyres the air pressure in the innertube "clinches" the tyre-assembly in place.

Up until the late '80s, the choice was between plain pedals or pedals with toe clips and straps. Since "clipless" pedals provided a way to have a secure attachment to the pedal without the use of "toe clips", the name stuck, even though it is sometimes confusing to newcomers. "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".

Club bicycles were the elite, high-performance machines in England during the 1930s-1960s, popular with members of the many active cycling clubs. The poorer, less performance-oriented club members would ride sports bicycles, but the more hard-core "clubmen" would have true club machines. A club bicycle will typically have Reynolds 531 frame tubing, a narrow, unsprung leather saddle, reversed North Road handlebars (or drop bars), steel "rat trap" pedals with toe clips and 597 mm (26 x 1 1/4) or 630 mm (27 x 1 1/4) wheels. Even fairly high-end models will use steel rims, which, at the time, were widely believed to be superior to aluminum. The steel Dunlop Special Lightweight rims used on the better club bicycles could give the aluminum rims of the day a run for their money. Club biycles would be likely to have a more exotic Sturmey-Archer hub, perhaps a medium- or close-ratio model, 3 or 4 speed. A very few even were equipped with the rare ASC 3-speed fixed-gear hub. Many club bicycles were single-speed machines, usually with a reversible hub: single-speed freewheel on one side, fixed-gear on the other. Starting in the late '50's, derailleurs began to be used on this type of bicycle as well. Although primarily intended for fast group rides with clubmates, club bicycles were also commonly used for serious touring, and also for time-trialing.

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A system in which the cranks are held to the axle by soft steel bolts which have a tapered flat side. These bolts are called “cotters”. The bottom bracket spindle upon which the cranks mount have one flat surface on the left side of the bicycle, and a flat surface half-way around the spindle on the other side of the bicycle. The cranks have a hole so they can slip onto the bottom bracket spindle, and then another, smaller hole drilled transversely through the crank. The cotter is inserted into this transverse hole to hold the crank on the bottom spindle, and prevent it from turning relative to the spindle. Cotters become worn, and should be replaced as soon as any clunking or slippage is detected. The slippage always feels like it is on the left side of the bike, but can be on either the left or right side.

Cruiser is a popular name for what used to be called a "balloon tyre" bike. This style of bicycle was most popular in the '40's and '50's and characterized by 26 x 2.125 tyres (if they have 1.75 or 1 3/4 tyres, they are considered "middleweights".) The upper top tubes and stays are usually curved for a "streamlined" look. Older cruisers usually had a straight lower top tube, later models were cantilever frame designs. Cruisers are built for ride comfort and are spectacularly heavy, had only one gear, and a coaster brake. This type of bike is quite impractical for hilly country, due to the weight, the lack of gears, and the low saddle position of older models. For this reason, cruisers traditionally were most popular in very flat places, such as Florida and the Souther California coast and became associated with beach resorts. The new generation of cruisers is much lighter and are also avaialable with multi-speed gearing. The classic balloon tyre bike - before it was known as a "cruiser" - was in many ways the precursor of the mountain bike.

An acronym for 'Chronic Training Load' It is a adefault  measure of the training load over the past 42 days, used in powertraining. CTL= fitness (the accumulated training you have done over a long period). The primary indicator in terms of overtraining is the rate at which you are increasing your CTL (fitness). 

Traditional bicycle ball bearings use cup-shaped races and cone-shaped races, with the bearing balls rolling between them. They come in pairs, either with two cones on the inside, held bewteen two cups, or, with two cups on the inside and two cones at the outside. In a conventional threaded bottom bracket, the cones are part of the bottom bracket axle, and the cups thread into the bottom bracket shell of the frame. The left cup is adjustable to permit the bearing to be fine tuned. It has a lock ring to secure the adjustment. The right cup is the "fixed cup", usually having a flange that bumps against the edge of the bottom bracket shell when it is screwed all the way in. In the case of hubs and pedals, the cups are part of the hub shell or pedal body and the cones attach to the axle. One or both of the cones will be adjustable, and usually have a locknut and a keyed washer to secure it.