- A -

AERO BARS: Extensions that stick out in front of the handlebars to allow the rider to get into an aerodynamically low position.

AERO WHEEL: A wheel designed to reduce wind resistance.

- B -

BAILOUT GEAR, GRANNY GEAR: The lowest available gear ratio. Implies a very low gear, often with a triple crank.

BAR-END SHIFTER, BARCON: A small shift lever that mounts on the tip of the handlebar.  Barcon is a trade name.

BEAD: One of the two inner edges of a clincher-type tire. It includes a strengthening metal or fiber cable to prevent the air pressure from stretching the tire larger than the rim.

BOTTLE CAGE: A bracket for holding a water bottle on a bicycle frame.

BOTTOM BRACKET: The bearings and spindle, located in the lowest part of the frame, to which the cranks connect.

BRAKE HOOD: The cover for the top of the brake lever assembly on a bicycle with drop handlebars. It provides a convenient place to rest your hands when riding in a more upright position.

BRAZE-ON: Any small fitting attached to a bicycle frame (typically by brazing or silver soldering) for guiding brake and shifter cables or for attaching water bottle cages, racks or the like.

BREAK A CHAIN: To split a chain.

BUTTED TUBING: Tubing with a wall thickness that is thinner in the center and thicker near the ends. It has a better strength/weight ratio than straight tubing.

- C -

CAMPY: A nickname for Campagnolo, an Italian bicycle component company.

CANTILEVER BRAKES: Caliper brakes in which the pivot point is below the rim and attached to the frame or fork.

CASSETTE: A cluster designed to be used with a freehub.

CHAIN SKIP: Slipping of a chain off the sprocket teeth when pedaling hard.

CHAIN SLAP: Banging of the chain against the chainstay. Usually caused by riding fast over rough terrain.

CHAIN SPLITTER: A chain tool.

CHAIN STAYS: The tubes that connect the bottom bracket to the rear wheel.

CHAIN STRETCH: Elongation of a chain beyond the standard .500 inch per link. It is not really caused by stretching, but by wear in the chain link bearings.

CHAIN SUCK: 1) Trapping of the chain into the gap between the chain stay and the chainring due to "sticking" of the chain to the chainring as it turns. 2) Any of various other conditions that cause a chain to vary from the proper chainline.

CHROMOLY: A chrome-molybdenum steel alloy used in bicycle frames.

CLEAT: 1) A slotted shoe attachment designed to grip a rattrap pedal. 2) The mechanism on the bottom of a bicycle shoe that locks into a clipless pedal.

CLINCHER TIRE, WIRED-ON TIRE: A tire that stays on the rim by the tire bead being captured between the rim walls. While widely used, the term "clincher" is actually a misnomer: It correctly refers to an obsolete tire type with extended sidewalls clinched between two movable parts of the rim. See BEAD, TUBULAR TIRE.

CLIPLESS PEDAL: A pedal designed to lock to a mating device (cleat) on the bottom of the cyclist's shoe by means of a special spring-loaded mechanism. Clipless pedals are so called because they replace toe clips as a means of tying your feet to the pedals. See RATTRAP PEDAL, SINGLE-SIDED PEDAL.

COG: A rear sprocket. (The normal meaning of "cogs" is "teeth," but bicycle parlance uses "cogs" to mean rear "cogwheels" or sprockets.)

COMPONENT GROUP: Same as group or gruppo.

CYCLOCOMPUTER, COMPUTER: A readout that clamps to the handlebars and indicates speed, distance, elapsed time and sometimes cadence, altitude, heart rate, etc.

- D -

DERAILLEUR: The assembly that "derails" the chain from one sprocket to another, in order to change gears.

DISH: The rear wheel hub on a bicycle is off-center from the rim to make room for the cluster. This is called "wheel dish."

DOUBLE BUTTED SPOKES: Swaged spokes. The spokes are thicker at the ends than in the middle.

DOWN TUBE: The frame tube that connects the head tube to the bottom bracket.

DROP HANDLEBARS: Racing-style handlebars with curving, swept-down ends which facilitate a low, aerodynamic riding position.

DROPS: The downward-curving portion of racing-style handlebars. You place your hands here when you want to get aerodynamic for fast riding.

DROPOUTS: The forward-facing slots into which the rear-wheel axle is clamped to mount the wheel. The forward slope allows the wheel to drop out forwards to facilitate changing the tire. See FORK TIPS.

DROPPING A CHAIN: Having the chain fall off a chainwheel (on either side).

- F -

FIXED-GEAR: A drive system which lacks a freewheel, meaning you can't coast. There usually is only a single gear ratio.

FLOAT: The amount of foot rotation available on a clipless pedal.

FOLDABLE TIRE: A clincher tire with non-metallic Kevlar beads. It folds for easy storage but is more difficult to change.

FREEHUB, FREEWHEEL HUB: A wheel hub with a built-in freewheel.

FREEWHEEL: 1) The ratchet mechanism that allows the rear wheel to turn without turning the pedals. Necessary to allow coasting. It can be part of the hub or part of the freewheel cluster, depending on the design. 2) A freewheel cluster. 3) A cluster, with or without a freewheel.

FRICTION SHIFTERS: A shifter in which the gear shift lever moves continuously: lever position determines which gear you are in. See INDEXED SHIFTER.

- G -

GEAR INCHES: The equivalent diameter of the drivewheel, with gear ratio taken into account. For example if, in a particular gear, the front chainwheel has twice as many teeth as the rear sprocket, then gear inches equals twice the wheel diameter.

GRANNY GEAR: An easy, bailout gear.

GROUP, GRUPPO: The collection of most components required to turn a frame into a usable bicycle. Generally includes the front/rear derailleurs, front/rear sprockets, crank, bottom bracket, headset, hubset, chain, brakes, brake and shift levers and sometimes the seatpost. Not usually included are the wheels/tires, pedals, saddle, fork, stem and handlebars.

- H -

HEAD ANGLE: The angle of the head tube, measured from the horizontal.

HEADSET: The bearings inside the head tube that support the steer tube.

HEAD TUBE: The frame tube that supports the steer tube, and thus the fork.

HOOD: Brake hood.

- I -

INDEXED SHIFTER: A shifter with a click stop for each gear position. See FRICTION SHIFTER.

INDEXED STEERING: A detent or grainy feeling in the headset bearing.

- J -

JERSEY: A bicycling shirt, often emblazoned with team logos and advertisements. Usually includes pockets in the back.


- L -

LUG: A short angled tube used to join and reinforce two or more tubes of a bicycle frame.

- N -

NIPPLE: A spoke nipple.

- P -

PRESTA VALVE: A special air filler valve used on most high-pressure bicycle tires. It is thinner than Schrader-type valves.

- Q -

QUICK-RELEASE BRAKES: Brakes with provision to easily open up the calipers for quick wheel removal.

QUICK-RELEASE LEVER: A lever used on wheel hubs, and sometimes seatposts, which replaces the locknut for easy, no-tool removal or adjustment.

- R -

RIM TAPE, RIM STRIP: A strip of plastic or cloth placed inside a clincher-type rim to protect the tube from sharp spoke edges.

ROLLERS: A type of training stand in which the rider must maintain balance to keep the bicycle upright.

- S -

SADDLE: A bicycle seat.

SCHRADER VALVE: Type of air filler valve used on automobile and some bicycle tires. See PRESTA VALVE.

SEAT POST: The removable tube that the saddle mounts onto.

SEAT STAYS: The tubes that connect the rear wheel to the top of the seat tube.

SEAT TUBE: The frame tube that connects between the top tube and the bottom bracket. The seat post inserts into the top of the seat tube.

SEW-UP TIRE: Tubular tire.

SKEWER: The portion of a wheel quick-release mechanism that extends through the hub axle.

SNAKEBITE FLAT: A flat tire caused by pinching the tire and tube between the rim sidewalls and a rock or other obstruction. It usually causes two parallel punctures in the tube that look like a snake bite.

SPLIT/BREAK A CHAIN: To disconnect a chain link so the chain may be removed from the bicycle.

SPOKE KEY, SPOKE WRENCH: A small wrench for adjusting spoke tension by turning the nipple.

SPOKE NIPPLE: The flanged nut that threads onto the end of a spoke to attach it to the rim.

STEER TUBE, STEERER, STEERING TUBE: The tube that goes through the head tube and connects the fork to the handlebar stem.

STEM: The tube that connects the handlebars to the steer tube.

SUSPENSION HUB: A ruggedized hub designed to be used with a suspension.

- T -

TENSION ROLLER, PULLEY, JOCKEY WHEEL, JOCKEY ROLLER: One of the two small idler sprockets in the rear derailleur.

TOP TUBE: The top, horizontal frame member which connects between the head tube and the seat tube.

TOPS: The part of the handlebar between the stem and the brake levers.

TRACK BIKE: A bicycle built for track racing. It is generally built as light as possible, with a fixed gear and no brakes. (A brake may be added for riding on the road.)

TRAINER, TRAINING STAND: A frame that converts a bicycle into an exercise (stationary) bicycle. Allows training indoors in bad weather.

TRIPLE CRANK: A crankset with three chainwheels.

TRUING A WHEEL: The process of making a wheel truly round by adjusting spoke tension by rotating the spoke nipples.

TRUING STAND: A fixture for holding and measuring a wheel while it is being trued.

TUBE: 1) A piece of tubing, usually part of the frame. 2) The tire innertube.

TUBULAR TIRE, SEW-UP: A tire in which the casing is sewn shut around the tube. Rather than using a wire-reinforced bead gripped by the rim wall, as in clincher tires, tubular tires are glued to a wall-less rim.

- W -

WORKSTAND, REPAIR STAND: A frame that holds a bicycle off the ground for convenient repair.

- 123 -

700C: A wheel size used on road bikes of approximately 700 mm (27.6 inch) diameter, including tire.

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