Glossary
A B C D F GH IJ L
MNPQ R S T UVW
Adjustable cup
The left-side cup in
the bottom bracket, which can be
screwed in or out to adjust the bottom
bracket bearings. Its also the cup to remove when overhauling the bottom
bracket.
Aheadset
A headset design that uses
a threadless steerer tube. The steerer
tube is secured in the headset bearings
by the Stem
Anti-seize
A type of grease laced with
lead particles, used to prevent two components from corroding together. Mainly
used on threaded fasteners - don't use
it in bearings (it isn't a high-speed lubricant.
Axle
The threaded shaft that passes
through the center of the hub that the
wheel rotates on. Sometimes used to refer to the bottom bracket spindle.
Axle nut
The nut that threads onto the
axle and holds the wheel to the fork or
frame.
Axle protrusion
The distance between
the bearing cone adjuster locknut on the
axle to the end of the axle.
Return to top
B-tension screw
The screw at the rear
of a Shimano derailleur that adjusts the
distance between the derailleur guide
wheel and the rear sprockets.
Bar ends
Extensions that bolt onto the
ends of a mountain bike handlebar and
offer the rider different hand positions.
Designed primarily for climbing hills and
for use on long stretches of road or trail
where the brakes aren't needed.
Bead
The part of a clincher tire that
you sometimes have to lever up over the
rim during installation. Usually reinforced with wire or Kevlar strands.
Bead seat
The part of the rim where
the bead of a clincher tire seats.
Bottom bracket
The bearing assembly that the crank arms are attached to.
Bottom bracket shell
The pan of the
frame that the bottom bracket is housed
in.
Bottom bracket spindle
The shaft
that the crank arms attach to and the
bottom bracket bearings support. Also
referred to as the bottom bracket axle.
Brake block
Another term for brake
pad.
Brake centering
Adjusting the brake
so both pads are equidistant from the
rim while at rest and contact the rim at
the same time when the brake Is applied.
Brake pad
The rubber part of the
brake that presses against the rim when
the brakes are applied. creating friction.
Brake pad toe-in
The difference in
distance between the ends of the brake
pad and the rim. The trailing end of the
pad (in relation to wheel rotation) should
contact the rim slightly before the leading end.
Brake release (or quick release)
A lever or button that can be disengaged
to allow the brake pads to spread apart.
making wheel removal easter.
Braze-ons
Small mounting bosses on
a bike frame for attaching water bottle
cages, racks, shifters, derailleurs, brake
arms, etc., attached by the process of
brazing.
Butted spoke
A spoke that is thicker
at the ends than in the middle.
Butted tubing
Frame tubing that is
thicker at the ends than in the middle,
but has the same outside diameter
along its length. This places more material at the stress points and eliminates
material in the middle, which makes for
lighter tubing.
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Cable
A control mechanism, composed of an inner cable (stranded wire)
and an outer casing, used for operating
derailleurs and brakes.
Cable carrier
The component in a
link-wire cantilever brake system that
joins the brake cable going to one brake
arm with the link wire that goes to the
other arm.
Cable hanger
A mounting boss that
holds a cable casing but lets the inner
cable pass through.
Cadence
Pedaling rpm (revolutions
per minute).
Cage
1. On the rear derailleur, the two
plates that hold the tension and guide
wheels. 2. On the front derailleur, the
two parallel plates that move the chain
from chainring-to-chainring. 3. A frame mounted water bottle holder. 4. Ball
bearing retainer.
Calipers
The parts of a brake that the
cable pulls on, through which force is transmitted to push the brake pads against the rim. Also called brake arms.
Cantilever brake
A brake with two
caliper arms, each one being mounted
on opposite sides of the frame or fork.
The most common type of brake found
on mountain bikes.
Cartridge bottom bracket
A self-contained, non-serviceable bottom bracket
axle and bearing assembly.
Center-pull brake
A brake design in
which the caliper arms pivot on a common mount attached to the frame or
fork, each arm being attached by a
straddle cable which the main brake cable pulls.
Chain breaker
A tool used for driving
a rivet out of a chain to separate it and
then driving it back in again to rejoin the
chain.
Chain rivet
The pins of a chain that
connect the individual Iinks.
Chain roller
The round part between
the plates of a chain that engage between the teeth of the sprockets and
chainrings.
Chain stretch
The amount a chain
"grows" as the rivets and rollers wear
out.
Chain whip
A tool used for unscrewing the small sprocket to disassemble a
freewheel, and also used to prevent a
freehub from turning while unscrewing
the lockring. Composed of a metal bar,
a short length of chain to grip the
sprocket, and a longer length of chain
that wraps around the sprocket to pull
on it.
Chainguard
A protective covering
over the chain and chainrings, designed
primarily to keep fingers and clothing
from getting caught in the chain
Chainring
The large sprocket(s) on a
crankset that pull on the chain as the
cranks are turned. Sometimes referred
to as a chainwheel.
Chainstays
The parts of a frame that
make up the bottom portion of the rear
triangle; the two tubes that travel be-
tween the bottom bracket and the rear
wheel dropouts.
Chainwheel
See Chainring.
Clincher
The common term used to
describe any bike tire that uses a separate inner tube.
Clipless pedal
A type of pedal that incorporates a foot retention system that
doesn't use straps.
Cogs
Another term for the rear sprockets.
Cone
The inner race of a ball-type
bearing assembly. Found on axles and
some bottom brackets.
Crank arm
The part of a crankset that
connects the pedal to the bottom
bracket.
Crank puller
A tool required to remove
the crank arms from the bottom bracket
spindle.
Crankset
The components that work
together to pull the chain: comprised of
the bottom bracket, crank arms, and
chainring(s).
Cup
The outer race of a ball-type bearing assembly. Found on bottom brackets and headsets. (On axle bearings the
cup is integral with the hub.)
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Derailleur
The cable-actuated mechanism used for shifting the chain from
one sprocket or chainring to another.
Derailleur chain
Type of chain designed for use with derailleur shifting
systems
Derailleur hanger
The protrusion on
the rear-wheel dropout to which the derailleur mounts.
Dish
The position of the hub in relation
to the rim. A wheel whose hub flanges
protrude equidistant from each side of
the rim has zero dish. Rear wheels on
multi-speed bikes must have a certain
amount of dish to make room for the
freewheel or freehub sprockets.
Down tube
The part of the frame that
travels from the head tube to the bottom
bracket: it forms the bottom part of the
front triangle.
Drop bars
Typical handlebars found
on road bikes that curve down from the
tops of the bars.
Dropouts
The machined plates with
slots that a wheel axle fits into: also the
slots themselves.
Return to top
Ferrule
The metal cap on the end of the cable casing.
Fixed cup
The cup of an adjustable
bottom bracket assembly that Is
threaded into the right-hand side of the
frame.
Fork
The tubes that hold the front
wheel to the bike.
Fork crown
The part of a fork that attaches the fork blades
or tubes to the
steerer tube.
Fourth-hand tool
A tool used for
pulling cables tight.
Freehub
A ratcheting mechanism to
which the rear sprockets mount, also incorporating the drive-side axle bearing.
Freewheel
A ratcheting mechanism to
which the rear sprockets mount, independent of the wheel axle bearings.
Freewheel remover
A special tool
used for removing a freewheel.
Friction shifters
Non-index type shift
levers that rely on friction to hold the derailleur in position.
Front triangle
The front structural part
of the frame, comprised of the top tube.
seat tube, head tube, and down tube.
Return to top
Gooseneck
Another term for the stem.
GripShift
A type of index shifter that
changes gears by rotating the innermost
part of the handgrip.
Guide wheel
The upper wheel of a
rear derailleur - it moves the chain from
one sprocket to another.
"H" screw
The adjustment screw on a
derailleur that sets the limit of travel towards the high gear (big chainring up front, small sprocket at the rear). When
adjusted correctly it prevents the chain
from jumping off between the small
sprocket and the frame (rear) or off the
large chainring (front).
Head tube
The part of the frame that
the fork steerer tube passes through.
Headset
The bearings that support the
fork steerer tube.
Hub
The center portion of the wheel,
containing the axle and bearings.
Hyperglide chain
Derailleur chain designed for use with Shimano Hyperglide
shifting systems, with specially shaped
plates to provide quick, smooth shifting.
Requires a special replacement rivet if
separated.
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Idler wheels
Another term for the
guide and tension wheels of the rear derailleur.
Index shifters
Shifters that change
gears with a click of the lever.
Indexed steering
"Notchy" steering
caused by a worn-out headset.
Jockey wheels
Another term for the
guide and tension wheels of the rear derailleur.
Return to top
"L" screw
The adjustment screw on a
derailleur that sets the limit of travel towards the low gear (big sprocket on the rear, small chainring on the front). When
adjusted correctly it prevents the chain
from jumping off the big rear sprocket
and tearing out spokes or from coming
off the small front chainring and landing
on the bottom bracket shell.
Link-wire cantilever brake
A cantilever brake setup where the main cable
connects to one cantilever arm and the
other arm is connected to the main cable by a shorter cable and cable carrier.
Locknut
A nut that tightens up against
an adjuster nut to prevent it from moving.
Lockring
The ring nut that threads
over the left side bottom bracket bearing cup and locks it to the bottom
bracket shell when tightened.
Lugs
Castings with external metal
tubes into which frame tubes are brazed
or glued.
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Main triangle
See Front triangle.
Master link
A link chain that can be
separated without having to drive out a
rivet.
Narrow chain
Derailleur chain with a
narrower width than a standard derailleur
chain. Most require a special replacement pin if separated.
Nipples
The nuts that fit through holes
in the rim and thread onto the ends of
the spokes.
Presta valve
A type of tire tube valve
that has a small nut on top that must be
loosened to add or release air.
Quick-release
A device that allows
rapid detachment or adjustment of a
component. Found on some wheels and
seat binder bolts.
Quick-release skewer
The thin rod that passes through the center of a hollow axle.
Return to top
Race
The part of a bearing assembly
that the bearing balls or rollers contact.
Rear triangle
The rear structural part
of the frame, made up of the seat stays,
chain stays, and seat tube.
Retainer
The plastic or pressed metal
cage that holds bail bearings a specified
distance from each other.
Rim
The outer portion of the wheel
that the tire fits on.
Rim strip
A rubber liner that encircles
the rim and covers the spoke nipples to
prevent them from damaging the tube.
Rim tape
Cloth adhesive tape that
performs the same function as a rim
strip.
Return to top
Saddle
Another term used for a bicycle seat.
Schrader valve
An automotive-type
tire valve.
Seal
A synthetic rubber boot or flange
that fits over a bearing to keep contaminants out.
Seat post
The tube that the seat
mounts to.
Seat stays
The tubes of a frame that
span the distance between the seat
tube and the rear dropouts.
Seat tube
The vertical part of the
frame that forms the rear of the front triangle, running between the bottom
bracket and the top tube.
Sew-up tire
A tire that has its tube
stitched inside: must be glued to the rim.
Skewer
See Quick-release skewer.
Spider
The part of the right-side crank
arm that the chainrings attach to.
Spin
To pedal at a high cadence.
Spindle
The part of a bottom bracket
that the crank arms attach to.
Spoke
The wires that extend from the
hub to the rim.
Spoke guard
A plate, made from plastic or metal, that prevents the chain
from tearing out the drive-side spokes
on the rear wheel if the chain jumps off
the largest rear sprocket.
Spoke nipples
See Nipples.
Spoke wrench
A wrench used to turn
spoke nipples.
Sprocket
A gear on the rear wheel.
Steerer tube
The part of the fork that
passes through the head tube of the
frame and is supported by the headset
bearings.
Stem
The part that connects the handlebar to the fork steerer tube.
Stem binder bolt
The bolt in the center of a conventional stem that pulls up
on a wedge when tightened, fixing the
stem's position in the fork steerer tube.
Straddle cable
A cable that attaches
one brake arm to another. Used in
straddle-cable cantilever brakes and
center-pull brakes.
Straddle-cable cantilever brake
A cantilever brake setup where the main
cable connects to a yoke, which connects to a cable running between the
two cantilever arms.
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Tension wheel
The lower wheel of a
rear derailleur - it maintains tension on
the bottom run of the chain
Third-hand tool
A tool that squeezes
the brake pads against the rim to ease
cable adjustment.
Tire lever
A small plastic lever used to
pry a tire off of the rim. Usually more
than one is required.
Toe clip
A foot retention system
mounted on the pedal, consisting of a
metal or plastic cage that covers the
front part of the foot, sometimes secured at the rear by a strap that tightens
over the center part of the foot.
Top tube
The upper part of the front
triangle, connected to the head tube
and the seat tube.
Truing stand
A fixture that is used to
true-up wheels.
Trueness
The straightness, both laterally and axially, of a wheel as it rotates.
Tubular
See Sew-up tire.
U-brake
A type of brake that is similar
to a cross between a center-pull brake
and a cantilever brake.
Valve stem
The part of an inner tube
that protrudes through the rim that air is
added to.
Wheel dish
See Dish.
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