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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- A type of track race, often running six days continuously. Teams of riders would take turns riding and resting. Each team would have a small stick, carried in the back pocket. As one rider would relieve another, the stick would be passed from one to the other in a distinctive maneuver designed to transfer as much momentum as possible from the retiring rider to his relief. This style of racing was most associated with New York's Madison Square Garden, hence the name.
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The Maes bend is the most common type of drop handlebar. From the center, it goes straight out then bends forward in a gradual curve. When it has bent forward 90 degrees, it turns downward, and bends in a smooth, constant-radius curve approximately 160 degrees, then straightens out.
It is usually set at an angle such that the forward-bending section is tilted somewhat downward toward the front. The bottom flat part of the "drops" will normally be level, or slightly down at the rear.
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- Defunct French
manufacturer primarily of brakes. The Mafac "Racer" centerpull was the standard for high-end French bikes all through the '50s and well into the '60s.
"MAFAC" is an acronym from: "Manufacture Auvergnoise de Freins et Accessoires pour Cycle" (Manufacturer in the Auvergne of Brakes and Accessories for Cycles.)
Mafac Parts from Harris Cyclery
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- A race in which all the competitors start together at the same time, as opposed to time-trials or pursuits. Mass-start races were illegal in Britain for many years, which is a major reason for the popularity of time trials there.
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- A cyclist who habitually pedals hard in a high gear, at a slow cadence. The opposite of a "spinner." The "mashing" style is likely to cause knee injuries and leg cramps.
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- A special chain link designed to be easily disassembled and re-assembled. Most simple bicycles have these, but they are not generally used on bicycles with derailer gearing, because conventional master links are too bulky to clear the closely spaced sprockets.
The Craig Super Link and SRAM/Sachs Power Link are special master links that dowork with derailer gearing, and is a good choice for a cyclist who wishes to be able to remove the chain for cleaning.
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- A track event for two riders, who start together. Each rider would like to be behind the other for most of the race, because the rear rider has the initiative. As a result, most of the distance of a match sprint is covered at a very low speed. Suddenly, one of the riders attacks with a burst of energy, and the tempo changes from a slow cat-and-mouse dance to a full-out blast. This is the most popular track event, and is very exciting.
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- An American manufacturer of brakes and brake shoes. Mathauser was an early producer of hydraulic brakes, and also makes an ususual type of sidepull brake.
Mathauser is best known as a manufacturer of brake shoes. They are a distinctive ugly rust-red color, but they are the best that I have come across. They provide excellent stopping power wet or dry, and are very long lasting. I recommend them highly.
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- A traditional upholstered saddle, as used on older, less-expensive English 3-speeds (better models used leather saddles.) A mattress saddle has multiple small coil springs running along between the top and bottom of the frame, covered with a layer of felt or horsehair, and a leatherette/vinyl top. This type of saddle almost always has large coil springs at the back of the frame.
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- A major French manufacturer of parts. Mavic has long been one of the top manufacturers of high-quality rims. In the late '80's they started to branch out into other parts, including very well-received hubs and cranksets.
"MAVIC" is an acronym from "Manufacture d'Articles Vélocopediques Idoux et Chanel. (Idoux and Chanel were the names of the partners who founded the company in 1890.)
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- British term for derailer.
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- Every linkage that transmits power has a particular mechanical advantage. This is a ratio between the amount of force applied and the amount delivered. "Work" is defined as a force applied through a distance. When work is transmitted through a mechanism that has a mechanical advantage other than 1:1, the force can be increased at the expense of acting throught a reduced distance (as in the case of bicycle brakes, or gear shift levers) or the distance can be increased at the expense of reducing the amount of force transmitted (as in the case of the chain drive where the driving sprocket is larger than the driven sprocket.)
For a more thorough explanation of mechanical advantage, see my article on Cantilever Brakes.
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- International measuring system based on the meter (39.37 inches) as the unit of length. Metric bicycle parts and dimensions are usually given in millimeters (mm) (1/1000 meter) or centimeters (cm) 1/100 meter.
Most wrenches used on bicycles have sizes in millimeters.
The most common sizes are 8 mm, 9 mm, 10 mm, 13 mm, 14 mm, 15 mm, 17 mm, 32mm and 36 mm; also, Allen wrenches in 4 mm, 5 mm, 6 mm and 8 mm.
Less common are 7 mm, 11mm, 12mm 16 mm and 19 mm, 30 mm, 40 mm and Allen sizes 2mm, 2.5 mm, 3 mm, 7 mm and 10 mm.
Metric threading is used on most bicycles.
I have developed a color-coding system for quickly determining the size of a Metric wrench. This is explained in my article on Color Coding Your Tools.
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- Older design seatposts were (and cheap ones still are) simple pieces of pipe, which a saddle clamp wrapped around. The part of the saddle clamp that wrapped around the post had a series of serrations or ridges which mated with a similar set of serrations on the parts that gripped the rails of the saddle. The saddle could be tilted up or down, but only in increments which would allow these sets of serrations to mesh.
When seatposts with built-in clamps came onto the market, one of the major advantages that they were touted for was that you had a continuous range of angle adjustments, achieveable by looening the front bolt and tightening the rear (or vice versa). The buzzword to describe this feature was "micro-adjustable". This term came to become a general synonym for a seatpost with a built-in clamp, as opposed to the older "pipe" style.
Most newer seatposts are single bolt designs, and rely on serrations to maintain the saddle angle (the serrations are finer-pitched than the old saddle clamps). Despite the fact that these seatposts do not provide a truly continuous adjustment, tbey are still commonly referred to as "microadjustable."
For more on seatposts, see my article on Saddles.
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- Sun Tour's buzzword for compact drive.
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- A style of lady's frame in which the "top tube" consists of a pair of small diameter tubes running more-or-less straight from the upper head lug, past the seat tube, and on to the rear fork ends. A mixte frame thus has 3 sets of rear stays, instead of the usual two. A variant on the mixte uses a single, full sized top tube running from the upper head tube to the seat tube, but retains the middle set of stays. A lady's type bike that lacks the middle pair of stays is not a mixte.
Mixte frames are stronger than conventional lady's frames, particularly in resisting the tendency of the seat tube to get pushed backward in the middle when ridden by a heavy rider
In French, "mixte" would be pronounced "MEExt", but normal U.S. bicycle industry pronunciation is "MIX-ty".
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- A type of mass start race, usually on a track, sometimes on a criterium course. At each lap, the last rider over the finish line must withdraw, until there is only one rider left. This is also known as "devil take the hindmost."
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- When one piece of tubing is to be fitted tightly against another, as in the joints of a bicycle frame, the tube to be added must have its end cut in a curved shape so that it will fit against the tube it is to be attached to. This curved shape resembles the ceremonial headgear of a bishop, and takes the name "miter" from it.
A more prosaic name for this is "fish-mouth."
The accuracy and precision of the mitering of the frame tubes is fairly critical.
In the case of a lugged frame, a sloppy builder can usually get away with less-than-perfect miters, since the miters are mostly not visible, hidden inside of the lugs. Even so, the frame will be stronger if the miters are well fitted. With lugged frames, the quality of the mitering can often be judged by looking at the inside of the bottom bracket, where the seat tube, down tube and seat stay miters will usually be visible.
Some investment-cast lugs are designed to provide a stepped socket that accepts a square-cut tube. This makes mitering un-necessary
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- A major Italian manufacturer of brakes. They were the first to offer "æro" brake levers on a commercial basis.
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- British "Vise-Grip".
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- A type of adjustable wrench in which the jaws are perpendicular to the handle.
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- A structure, such as a bicycle frame, built as a hollow shell, without an interior framework. The strength of a monocoque structure comes from the shell alone. Monocoque bicycle frames are uncommon, but have been made from carbon fiber and from formed sheet aluminum.
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- An event in which a bicycle drafts behind a motor vehicle, usually a motorcycle. This was the most popular form of track racing in the 1920s and '30s. Special motorcycles called "Dernys" are used for track events. The motorcycle driver sits very erect and far back to improve the drafting effect. There is a horizontal roller mounted behind the rear wheel, so that, if the bicycle gets too close, the bicycle's front wheel will hit the roller, rather than a rigid part of the motorcycle.
Some road racers train behind a motorcycle, which allows the coach to accompany the rider, and teaches the cyclist to be comfortable controlling the bicycle at higher-than-average speeds.
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- Sir Alex Moulton, noted autombile designer, is also a cyclist and bicycle designer/manufacturer. He was an early pioneer in the development of fully-suspended bicycles. The original Moulton bicycles of the 1960's had 16 x 1 3/8" (ISO 349 mm) wheels. The small wheels reduce unsprung weight, reduce the overall size of the bicycle, and allow luggage to be carried lower, lowering the center of gravity. The 349 mm size was originally a juvenile size, and the fairly wide, low-pressure tires limited the performance of the early Moultons. Later models, currently known as "Alex Moultons" or "AMs" use a slightly larger diameter tire/rim (ISO 369 / 17 x 1 1/4) developed specifically to Moulton's requirements.
Early Moultons used a simple cross frame of large diameter steel tubing, with a reinforcing strut for the seat tube. The current "AM" series uses a very elaborate "space frame", consisting of a network of many pieces of small-diameter steel tubing, lined together into a truss made up of many small triangles. AM models also are designed to separate into two roughly equal-sized pieces for ease of transport. There is also an "APB model with 406 mm (20") wheels.
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- "Mountain bike" (MTB) is the currently preferred term for bicycles made for off-road use. Mountain bikes use 559 mm wheels, have at least 15 speeds, and usually have cantilever brakes. There was an attempt to make a copyright out of "MountainBike", but the term has become generic. Some have tried to promote the term "All Terrain Bike" (ATB) as an alternative, or to designate some subtle variant of the mountain bike, but this term has largely fallen into disuse.
The mountain bike is in many ways a hybrid design, a cross between a BMX bicycle and a touring bicycle.
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- A style of handlebar similar to an inverted North Road bar, but flatter and wider, with larger radius bends. Usually supplied in "road" diameter (23.8 mm / 15/16") used with drop-bar type brake levers, often with barcons. Previously available in a smaller diameter (22.2mm / 7/8") for use with mountain bike type controls. Designed by Grant Petersen, formerly of Bridgestone bicycles. This was standard equipment on the legendary XO-series Bridgestones.
Drew Saunders has a Web document devoted to the Moustache handlebar.
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- A triangular flap that hangs down below the front fender to protect the feet from spray. Sociable cyclists who ride in wet conditions sometimes have rear mudflaps to protect their companions.
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- British term for fender.
N.D.S.
- See "D.S."
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- Noted manufacturer of lugs, no longer in business.
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- The official metric unit of force.
1 Newton = .2248 pounds
An unofficial metric unit of force is the kilopond or "kilogram of force." This is the force exerted by the weight of a 1 kilogram mass in normal earth gravity, and is equal to 9.81 Newtons or 2.2 pounds.
The "kilogram of force" is a disreputable unit, abhored by pedantic purists. Nevertheless, it is commonly used in the bicycle industry, particularly when dealing with spoke tension, since the most popular tensiometer is calibrated in these units.
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- Many beginner cyclists assume that there must be some standard sequence of gears on a multi-speed bike, for instance that a 10-speed bike must have a "1st gear, 2nd gear 3rd...10th."
In fact there is no such standard gear numbering system, nor should there be, because some gears put the chain at bad angles, and should not be used.
I know of 4 different "systems" for numbering the gears of a 10 speed:
- The 5 gears using the small chainwheel are 1-5, those that use the large chainwheel, 6-10
- The 5 gears using the small chainwheel get the odd numbers 1-3-5-7-9, large 2-4-6-8-10
- The gears can be ranked numerically by how high each gear is. The pattern would then depend on the sizes of the sprockets involved.
- I used to know an engineer who used a variation on the previous system: He plotted everything out on semi-logarithmic graph paper, and came to the conclusion that his 10 speed was actually a 12 speed that was missing 2nd and 11th. He numbered his gears 1,3,4,5,6,7,8,9,10,12.
As you can see, if you try to actually communicate with somebody about your bike and use a term such as "9th gear" you will probably fail to communicate.
When discussing issues related to the function of the derailers, it is better to refer to "the second largest rear sprocket" or "the middle chainwheel".
When discussing issues related to the biomechanical aspects of gearing, it is better to use terms that relate to the actual ratios, such as gain ratio, gear inches or development.
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- The nut that secures the end of a spoke to the rim of a bicycle wheel. Nipples have a normal right-hand thread, but because they are normally seen from the "bolt" side, it is often confusing which way to turn them. It is as if you were watching the hands of a clock move clockwise, but the clock was transparent, and you were looking from behind it.
Of all the things bicycle mechanics do, adjusting spoke nipples is the one that requires the most skill and experience. If you wish to learn more about this process, see my article on Wheelbuilding.
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- Leading Japanese manufacturer of handlebars and stems, most notably the Technomic stem.
Noodle
- A curved piece of tubing commonly used to lead the brake cable around a right-angle bend where it attaches to a direct-pull cantilever brake, such as a Shimano V-brake ®. Most direct-pull brakes come with alternate noodles to accommodate left-front or right-front setup.*******
Normal
- This is a slippery, dangerous term, because what's normal to one person at one time is abnormal to another person, another time. The use of "normal" to describe brake reach is a very common source of confusion and trouble.
North Road bend
The style of handlebar used on most English 3-speed bicycles. This is a fairly narrow bar with a slight rise, grips nearly parallel to the frame.
This design was formerly associated with the North Road Cycle Club, north of London. It is a reversible design, most often used in the upright position, but quite serviceable in the dropped position as well, for a more agressive riding position. In the reversed position, it resembles a Moustache handlebar, but with sharper bends and a bit more drop.
N.O.S.
- "New, Old Stock. Refers to classic parts and accessories that have never been sold or put into use.
Nuovo
- Italian for "new" as in the Campagnolo model names "Nuovo Record" (New Record) and Nuovo Tipo (New type).
N.R.
- Nuovo Record, the classic Campagnolo parts group of the '70s and early '80s. Some of the parts in this group, particularly the derailers, were different from the previous "Record" group; others were the same.
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- A conventional, non-quick-release hub, with a solid axle.
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- Shimano's system of splined bottom brackets.
Octalink ® cranks come in one of two different spline
patterns:
- The original "V1
" type for:
- XTR (BB-M952 9-speed)
- Dura-Ace (BB-7700 9speed)
- Ultegra (BB-6500 9-speed)
- 105 (BB-5500 9-speed)
- The later "V2" type for:
- Deore XT (ES70/71)
- Deore LX (ES70/71)
- Deore (ES50/51)
The V2 BBs work with FC M752, FC M751, FC M572, FC M571, FC M510-8 and FC M440-8 cranks.
- Tiagra 2005 (4401,4404)
- Sora 2005 (3301,3304)
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- Original Equipment Manufacturer. This refers to parts sold by a parts manufacturer to a bicycle manufacturer for installation on new bicycles at the factory
- O.E.M. pricing is the lowest possible price structure, since the parts are sold in the largest quantities.
- O.E.M. packaging is less expensive per unit, because hundreds of parts are packed in a single crate, with little or no internal packaging material.
- O.E.M. parts are often cheaper versions of parts sold to the aftermarket, even though they may have the same model designation.
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- Fork rake
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O.L.D.
- Over Locknut Dimension.
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- A one-piece crank (OPC) consists of a single steel forging which constitutes the left crank, axle, and right crank in a single piece of steel. This type of crank set is found on older U.S. made bicycles, and many current low-end bicycles. It is also commonly used on BMX and freestyle bicycles.
One piece, or "Ashtabula" cranks are heavy but very strong and reliable. They are also much easier to work on than any other type of crankset, requiring no special tools. You can completely overhaul a one-piece-crank bottom bracket with just a large adjustable wrench and a screwdriver.
There are two different threadings used on one-piece cranks. Most are 24 threads/inch, but some, notably older Schwinn and Mongoose bicycles, used 28 tpi. The bearing retainers and cups are also slightly different between the two models. Although they both use 5/16" balls, 24 tpi units use a #66 retainer with 10 balls, while the 28 tpi units use a #64 retainer, with 9 balls. This is one application where retainers are essential, it is almost impossible to assemble a one-piece crank bottom bracket with loose balls.
One-piece cranks only fit in bicycles designed for them, with large-diameter, threadless bottom brackets. It is possible to buy adapter kits to allow three-piece cranks to be used in this type of bottom bracket shell.
One-piece cranks are made in a smaller diameter than other crank designs, so that the bearing cones can be installed. As a result, they have to use a smaller diameter (1/2" x 20 tpi) pedal thread.
The left side cone has a left thread, and uses a lock nut and keyed washer to secure the adjustment.
The right side cone has a right thread, and secures the chainwheel to the crank.
O.T.B.
- This abbreviation has at least three bicycle-related meanings:
- Only The Best, a bicycle brand sold by Charlie Hamburger in Boston, 1940s-'50s.
- Off The Back, i.e. left behind by the peloton, out of the race.
- Over The Bars, usually resulting from a head-on collision.
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- A long-obsolete term for a high-wheel bicycle, as opposed to a "safety" bicycle, i.e., a modern style
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- The distance between the outermost locknuts of a conventional hub axle, or whatever equivalent parts fit against the inside surfaces of the fork ends of a frame. They must match the spacing (see chart) of the frame that the wheels are to be installed in.
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- Larger in diameter than the traditional sizes. This term is commonly used for headsets and frame tubing. Oversized parts are stiffer, and can be lighter for their weight if the walls are made thin enough. If the walls become too thin, however, they become too easy to damage by denting.
Traditional forks used 1" (25.4 mm) diameter steerers. Oversized steerers are 1 1/8" (26.8 mm) or, less commonly, 1 1/4" (31.8 mm). Details on sizes are listed under headsets.
Traditional frames used 1" (25.4 mm) top tubes, 1 1/8" (26.8 mm) seat tubes and down tubes, and 1 1/4" (31.8 mm) head tubes. When BMX racing became popular, frames built to these old standards couldn't always hold up to the rigors of BMX competition. Since the wide availability of T.I.G. welding freed designers from the need to use tubes that would fit standard-size lugs, oversized tubing became the norm for BMX frames. This design and technology was later adopted by builders of mountain bikes.
In the interest of improved chainwheel/tire clearance, some mountain bikes have "oversized" bottom brackets, with a shell width of 73 mm, rather than the standard 68 mm.
