|Road Bike Anatomy
The frame is the skeleton of a bicycle. The most common
type of frame is called a "diamond" frame,
consisting of two triangles. The front triangle consists
of: the seat tube, a center vertical tube. The top
tube, a top horizontal tube. The down tube, a bottom
diagonal tube. And the head tube, the front vertical
tube. The rear triangle includes: the seat tube, seat
stays, the rear vertical tubes and chain stays, the
bottom horizontal tubes.
The saddle, often called a "seat", designed
for the rider to site on as they ride yet is not intended
to support the rider's entire weight. Classic saddles
are made of leather stretched over a metal frame that
will mold itself to fit the shape of its rider.
Most modern bicycles come with plastic saddles which
require no break in. Plastic saddles are also lighter
and less expensive than leather.
|Seat Post Binder
The seat post binder clamp secures the seat post into
the frame’s seat tube. It may be a conventional bolt
with a nut, an Allen bolt, or a quick release.
The seat post is the tubular support that holds the
saddle and connects it to the frame. The seat post telescopes
into the seat tube of the frame, providing the adjustment
for saddle height. Many modern seat posts have a "micro
adjusting" saddle clamp mechanism built into the
top of the post that allows for fine angle adjustments
of the saddle.
Most modern bicycles use cables to control the brakes.
Brake cables consist of two parts, an inner cable of
twisted steel wire, and an outer cable housing.
In many bikes the housing doesn’t run along the full
length of the cable, but transmits the compressive part
of the load to the frame by means of housing cable stops.”
The rear brake located over the rear wheel, usually
attached to seat stay, is the primary brake for controlling
speed and stopping. The rear brake is controlled by
the right hand brake lever.
The bicycle rides on its tires. The tires are made up
of three parts: 1 Two hoops of strong steel wire, called
beads that hold the tire into the rim. 2. The nylon
cloth cords forming the body of the tire, woven between
the two beads. 3. The outer rubber holds it all in.
The rubber is thicker where it contacts the road and
is is called the tread. Most bicycle tires are not airtight
by itself, so they use an inner tube.
The rim is the outer metal hoop of a bicycle wheel with
a U shaped cross section. Although the spokes go through
the rim it does not include the spokes.
Spokes are the wires connecting the rim to
the hub of a bicycle wheel. Spokes have a head, like
the head of a nail, to keep it from pulling through
the flange of the hub. Immediately after the head
the spoke takes a right-angle bend, also known as
the "elbow" of the spoke. The outer end
of the spoke is threaded, and a special nut called
a nipple fits through the rim and screws onto the
The spoke nipple is the nut that secures the threaded
end of a spoke to the rim of a bicycle wheel.
A cassette, is the group of sprockets, or toothed rings,
and spacers designed for use on a rear hub of a multi-speed
bicycle. Some of the sprockets and spacers may be semi-permanently
attached to one another by bolts or rivets. A freewheel
is a form of rear bicycle wheel that has a device freeing
it from the driving mechanism, as when the pedals are
stopped in coasting.
A rear derailleur is a mechanism for moving the chain
from one sprocket to another of the rear cluster to
change gears of a multi-speed bicycle.
A rear derailleur consists of a parallelogram which
moves a cage with two chain pulleys, a jockey pulley
and a tension pulley.
A chain is a looping circular set of links to transfer
power from chainring to the cluster of gears on the
rear wheel. The chain ring bolts to the crank arm spider.
A front sprocket or toothed rings that attaches to the
crank by being bolted on to a spider.
The crank is the arm, or lever, which extends from the
bottom bracket axle and connects the pedal. Sometimes
called a "crank arm".
The pedal is the part you put your foot on. The axles
of the pedals screw into the cranks. There are different
types of pedals, platform pedals to step on and clipless
that will bind your shoe to the pedal axel.
A water bottle cage braze-on is a small fitting permanently
attached to a frame allowing you to place a waterbottle
cage on your bike.
A headset is the bearing assembly in the front of the
frame that connects the front fork to the frame, allowing
the fork to turn.
The stem connects the handlebars to the fork steering
|Handlebar & Tape
The Handlebar is is a tube attached to the stem. Attached
are brake levers and shifters. Conventional handlebars
are divided broadly into two styles: "drop"
which are wrapped in cushioned tape, and "upright"
which require a cushioned grips.
The brake hood is the rubber covering above the brake
lever. The brake hood gives another hand position on
the handlebar of a road bike.
|Brake & Shift
Brake & Shift levers are levers on the handlebar
to activate the brake or shift gears through a cable
connection: Left side is front brake and front derailleur,
right is rear brake and rear derailleur.
The front brake located over the front wheel, and
usually attached to the fork. It is the secondary
brake for controlling speed and stopping. The front
brake is controlled by the left hand brake lever.
If used by itself, your likely to be thrown over the
A cable stop is a fitting at each end of a piece of
cable housing with a hole in the center, which will
let the inner cable slide through.
The front fork consists of two blades that go down to
hold the the wheel axle, the fork crown, and the steerer.
fork is attached to the main frame through the head
tube and the headset and secured by the stem.
In a quick-release hub, the skewer is a metal rod that
runs through the middle of the wheel’s hollow axle and
attaches the wheel to the dropouts in the frame and
fork. The skewer with have a quick-release cam and an
The center part of a wheel, to which the spokes attach.
it consists of an axle, which attaches to the fork ends,
and bearings allowing the wheel to revolve around the
The valve stem is the stem of the tire’s inner tube
that sticks out of the wheel’s rim, with a valve on
the end allowing you to fill the tire with air. There
are primarily two types of valve stems on bicycle inner
tubes sold in North America, the Schrader valve which
holds the valve inside the stem as in most automobiles,
and the Presta valve which has a narrower stem and the
valve exposed on the stem's end.