Sheldon Brown's
Bicycle Glossary Ch - Ci
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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 nominally the width where the sprocket teeth fit in. Bicycle chain comes in four basic widths:
There is some confusion in these numbers because the actual width of a 1/8" sprocket is typically 1/8"(3.175 mm) and the gap between the inner side plates of the chain must be slightly wider to fit over the teeth. The width of the teeth on derailer-equipped bicycles with 5 or 6 rear sprockets was traditionally 2 mm, and the 3/32" (2.30 mm) chain would fit over those teeth -- but the smaller widths with larger number of sprockets are not as well standardized. Chains for derailer applications also come in various external widths. Newer clusters which have more sprockets also use chain with thinner side plates and with rivets whose ends are flush with the side plates.
For more information on chains, see my article on Chain Maintenance.
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 derailer 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.
In the case of derailer geared bicycles, the chainline is not perfect in most gears. The worse the chainline, the worse the mechanical efficiency 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:
Also see my article on chainline
For information on interchangeability, see: Bolt Circle Diameter.
This 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 and fall.
Chain suck is commonly caused by bent chainring teeth, dirty chains, or, occasionally, burrs on the teeth of new chainwheels.
Jonathan Levy has an extensive Web site about Chain Suck
A tool used to press the rivet pin of a chain partway out of a link, in order to disconnect ("break") a chain to shorten it or to remove it from the bicycle.
A chain tool has traditionally also been used to insert a rivet pin to reassemble or lengthen a chain. Some narrow chains require replacement of a rivet pin instead, though many chains are equipped with a special link which can be disassembled and reassembled without pressing out a pin. For 1/8" inch wide chains, this is called the master link. The SRAM Power Link and similar products from Wippermann and KMC work with chains on derailer-equipped bicycles. With the narrowest chains, options become more limited.
Also see my article on chains.
For information on interchangeability, see: Bolt Circle Diameter.
If you don't have a chain whip, or if you are trying to remove a particularly stubborn threaded sprocket, you can substitute a short length of chain held in a vise:
Genuine chamois is expensive and requires extra care in washing and treatment to preserve it, so it is no longer in common use for cycling shorts. Most newer cycling shorts have artificial "chamois" made of specially woven cloth.
In the 2005 model year, 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 tires, and medium width front tires. Choppers tend to be heavy, sluggish bikes, suitable for short leisurely rides in flat terrain.
Cinelli is especially noted as a manufacturer of handlebars, handlebar stems and lugs.
Practically all top-of-the-line racing bikes in the 1970s were equipped with Cinelli handlebars and stems.
Cinelli also pioneered plastic saddles for high end bikes, under the Unica name.
Cinelli was probably the first to offer "clipless" pedals, with the infamous Cinelli M71 "death cleats." These "step-in" pedals required the rider to reach down and manually release each pedal before unclipping was possible!
Last Updated: by Harriet Fell