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5: Chain
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A chain has about 100 links.
Each link has its own bearing. It delivers energy
from your feet to the back wheel of the bike by
turning the freewheel in the back of the bike as
you turn it with the chainwheel. Different gear
ratios are possible by shifting the chain form one
sprocket to the another.
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6:
Freewheel
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The freewheel is a bundle of
five (more or less depending on the bike model)
gears attached to the rear wheel hub. The chain
turns the freewheel which allows the rotation of
the rear wheel. The freewheel contains a ratchet
system to allow the bike to coast forward without
moving the chain or pedals.
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7: Front
Derailer
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This mechanism moves the chain
from one chainwheel to another. It is controlled by
a shift lever (9) on the left side of the bike.
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8: Rear
Derailer
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This mechanism moves the chain
from one gear to another on the freewheel. It is
controlled by the shift lever (9) on the right side of the bike.
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9:
Gear-shift
levers
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These are usually referred to as
shifters. There are two levers; one on the right
side of the handle bars and one on the left. When
the rider moves the gear-shift position the
derailers select the different gear ratio.
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10: Tension
Roller
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This is located in the rear
derailer. This is a system of two small sprockets
which provide tension to keep the chain taut. It
moves with the chain as gears are shifted.
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11: Hubs
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The hubs contain the bearings
for the wheel. The hub flanges usually have 36
holes for spokes.
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12: Quick-
release
levers
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This is a lever system which
replaces a nut and bolt for fastening the wheels to
the frame. The system is named as it is because it
allows the cyclist to remove a wheel, or adjust his
seat instantly without the use of tools.
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13:
Spokes
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Each wire spoke has a wire
nipple wick connecting it to the rim. The nipple is
threaded. This provides a way to tighten or loosen
the spoke which adjusts the wheel for stiffness,
and removes wheel wobble.
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14: Rims
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These steel or alloy bands hold
the tires and connect to the axle and hub assembly
by means of the spokes.
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15:
Tires
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There are two basic types of
road biking tires available. The clinchers are for
touring and recreation. The sew-ups are for racing
and high-performance cycling. Each type of tire
requires a different kind of rim.
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16: Tire
Valves
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This is a device where you pump
air into the tire tube to inflate the tires.
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17:
Saddle
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There are two purposes of the
saddle (seat). The first is to support you and the
second is to place your body in its most efficient
riding position in relation to the pedals and
handlebars.
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18: Seat
Post
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This is a steel or alloy tube
that connects the saddle to the bike frame and can
be adjusted depending on the rider's height.
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19: Seat
Tube
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This is a frame tube that runs
from the seat to the bottom bracket.
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20: Top
Tube
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This is a frame tube that runs
from the seat to the head tube.
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21: Seat
Stays
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This is a frame tube that runs
from behind the seat to the rear axle of the
bike.
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22: Seat
Lug
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This is a pressed-steel
reinforcement that connect the top tube, seat tube,
and seat stays to the frame. It has a clamping
device which provides a way to tighten the seat
post into the frame (usually by quick-release
mechanism).
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23: Chain
Stays
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These are frame tubes that run
from the bottom bracket to the rear wheel of the
bike.
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24: Rear
Dropouts
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This is a lug attached to the
end of the chain stays. This provides a junction
for the chain stays and seat stays. It also
provides a surface for attaching the rear wheel to
the frame. The dropout on the right side often has
a built-in bracket for fastening the rear derailer
to the frame.
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25: Head
Tube
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This is a frame tube that joins
with the top tube and down tube of the bike.
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26: Front
Fork
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This assembly holds the front
wheel and connects it with the frame through a
system of bearings mounted in the head tube.
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27: Fork
Crown
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This is a metal assembly that
joins the two fork tubes to the steering
tube.
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28: Front
Dropout
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These are also called the fork
tips. These are lugs attached to the front fork
tubes which provide a solid metal surface for
attaching the front wheel axle to the frame.
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29:
Headset
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This is a ball-bearing assembly
which includes one bearing at the top and one at
the bottom of the head tube/fork assembly. This
system of bearings allows the front wheel to be
turned while holding the fork in the frame. It is
important that you have a good-quality headset so
that you bike can absorb shock transmitted form the
road through the front wheel while also allowing
the bike to be smoothly steered.
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30: Lugs
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These metal reinforcements are
used wherever one or more frame tubes come
together.
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31: Down
Tube
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This is a frame tube that runs
from the head tube to the bottom bracket.
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32:
Handlebars
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The handlebars are not only used
to steer the bike but are a integral part of the
leverage system by which the bike is powered
forward. Pulling up on the handlebars also
increases the force exerted on the petals.
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33: Handlebar
Stem
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This is a metal clamp assembly
fastening the handlebars to the front fork. They
come is many different sizes, making the distance
between the handlebars and the seat longer or
shorter to accommodate individual rider
differences.
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34: Caliper
Brake
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These are either side-pull or
center-pull brakes. They are shaped like calipers
and press the brake pads against the wheel rim
which in turn stops the bike.
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35: Brake
Lever
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This is a hand lever, mounted to
the handlebars, that allows the rider to control
the brakes.
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36: Brake
Cable
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This is a thin wire cable that
runs from the brake lever to the calipers,
controlling the brakes.
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