Racing Glossary – A Must Know for the Beginners in Biking!

by Rohan

“..and we saw him backing it in almost at every single corner!”, “.. the exit from that line was super cool!”

Sounds too confusing? Biking is considered to be all about speeding up only! But there’s much more to it! And when a newbie biker sees some hardcore bikers share a chat.. it all sounds Greek and Latin to him/her.

So, why not to start with ABCD of biking? Here is a racing glossary to help you with! Feel free to ask any queries! The terms are listed in an alphabetical order.

Racing Glossary

ABS: Antilock Brake System
A component added to the motorcycle braking system that detects wheel
lock up. The system rapidly modulates the brakes to prevent skidding
(and attendant loss of traction), allowing the rider more braking
control and increased riding safety.

Aerodynamics
Motorcycle aerodynamics refers to bike designs that have as little air
resistance as possible to achieve greater speeds or to improve rider
comfort. Wind tunnels aid manufacturers in their development of
improved aerodynamic motorcycle models which result in the different
configurations of windshields, fairings, body work and other
components.

Air Cooling
A method of dissipating heat from a motorcycle engine to keep it at
operating temperature by way of air flow. In practice, cooling is
effected by air rushing around a moving motorcycle engine and is aided
by the use of small engine fins to facilitate heat transfer into the
passing air. Compare Water Cooling.

Armor
Protective padding used to reinforce motorcycle apparel. It is
designed to absorb energy on impact to help protect the rider in the
event of a crash. Armor is available to better protect a rider’s back,
shoulders, chest, elbows, hips and knees.

Backing It In
Going into a corner with the rear of the motorcycle sliding while the
rider is counter-steering. This is a way for a rider to scrub off
speed and set the motorcycle up for a fast exit from the corner. “I
was trying so hard I was backing it in to almost every corner.”

Bagger
A motorcycle with touring accessories like saddlebags, top box, a
trunk, etc.

Balaclava
A thin pull-over head and neck cover with eye slits for winter usage
under a motorcycle helmet.

Bash Plate (aka Skid Plate)
A protective plate fitted under the engines of off-road machines to
prevent damage caused by grounding.

Bcom
Bluetooth Intercom headset for motorcycle helmets.

BDC: Bottom Dead Center
The point during crankshaft rotation at which the piston is in its
lowest possible position.

Berm
Built-up dirt on the outside of a turn, either created with a
bulldozer or as riders continually go through the turn. A berm helps a
rider take the turn much faster because it acts as banking.

Bevel
The angle that one surface makes with another when they are not at
right angles.

Bevel Gears
A pair of gears with faces cut at an angle of 45°, allowing drive to
be turned through 90°.

Big Dog Rider
An experienced and aggressive motorcyclist known for feats of daring
and skill, such as riding at high speeds on public roads, without
apparent fear of accident or arrest.

Binders
Motorcycle brakes

Blind Corner or Blind Turn
A turn in the road that is visually obstructed and prevents the rider
from seeing the path of the road around the corner. This makes the
rider blind to the turning radius, approaching traffic, and road
condition until after the rider has entered the turn and can then see
around the trees, hillside, etc.

Block Pass
Going into a turn, a rider attempting a block pass will accelerate
before the apex and slip his motorcycle on the inside of the leader,
then quickly pivot and make the turn directly in front of the other
rider. The rider being passed must brake because his line is now
blocked.

Body English
A method used by motorcycle riders to help control lean angle or
direction independent of the handlebars by moving body position on the
motorcycle.

Bore
The measurement of a cylinders diameter

Bottom Out
When the suspension runs out of travel and bumps against its internal
stops. “My rear suspension bottomed out over the big bump after turn
five.”

Brake Horsepower (BHP)
The measure of an engine’s horsepower without the loss in power caused
by the gearbox, generator, differential, water pump, and other
auxiliary components. Horsepower delivered to the rear wheel of a
motorcycle is less than at the engine. “Brake” refers to where the
power is measured: at the engine’s output shaft, as on an engine
dynamometer. The term “brake” refers to the original use of a band
brake to measure torque during the test (which is multiplied by the
engine RPM and a scaling constant to give horsepower).

Cage
A car, truck, van, RV or other vehicle that confines the inhabitants
within an enclosed space.

Cager
The driver of a car, truck, van, RV or other vehicle that confines the
inhabitants within an enclosed space.

Cam
An eccentrically shaped rotor that converts rotational movement into
linear movement. Cams are used in the operation of valves, contact
breaker points, and drum brakes.

Camshaft
A metal shaft with two or more cams (oval “lobes”) that rotates to
operate inlet and/or exhaust valves in a four-stroke engine.

Carbon Fiber
A high-tech material available in many motorcycle applications due to
its high rigidity and low weight which can allow improvements in the
power-to-weight ratio and suspension response of the bike.
Additionally, the distinctive look of the material has become trendy.

Carburetor
A mechanical device found on the intake side of the engine which mixes
fuel and air to create the volatile mixture that gets ignited in the
engine.

CC: Cubic Centimeters
A common engine size measurement for motorcycles.

CE Armor
A European system of grading motorcycle protective armor that
encompasses both energy absorption capability as well as pad shape and
size. The armor or pads are designed to offer added protection to a
rider going down on a motorcycle, particularly in the event of sliding
or lesser impacts. CE armor is made of hard foam pieces encapsulated
in softer foam which compresses on impact. In other words, it’s like a
helmet: if you land on it, you must replace it.

Centerstand
A mechanism that pivots down from the center of the motorcycle frame
to support the bike vertically with the rear wheel off the ground.

Chain Drive
A common motorcycle drive system that uses a multi-link steel chain
and toothed sprockets to transfer engine power to the rear wheel.

Chair (Sidecar)
A one-wheeled carriage for a single passenger attached to the side of
a motorcycle, producing a three-wheeled vehicle.

Chaps
Motorcycle clothing accessory designed for leg protection. They’re
usually made of leather and are fastened around the waist, with an
open back. They snap at the ankles and zip down the legs.

Chassis
The frame and suspension systems of a motorcycle.

Chicane
A part of the track consisting of back-to-back left and right turns.
Chicanes can be a part of the original track, or can be created, using
cones and hay bales, to slow the riders down for safety.

Chopper
A cruiser style bike that has a lot of the pieces of the bike “chopped
off.” The riders of the ’60s did everything they could to customize
their bikes and make them go faster. Thus, much of the existing bikes
they bought were chopped off. The bikes in the movie “Easy Rider” are
examples.

Clip-Ons
Handlebars that are clamped around the top of the fork tubes, rather
than bolted to the top triple-tree. This lowers a rider’s upper body
on the front of the motorcycle for a racier body position.

Clutch
A mechanism for transmitting rotation, which can be engaged and
disengaged. There are many different vehicle clutch designs but most
are based on one or more friction discs, pressed tightly together or
against a flywheel using springs. On most motorcycles, the clutch is
operated by the clutch lever, located on the left handlebar. No
pressure on the lever means that the clutch plates are engaged
(driving), while pulling the lever back towards the rider will
disengage the clutch plates, allowing the rider to shift gears.

Compression Ratio
In an internal combustion engine, the measurement of the difference
between cylinder volume at BDC and TDC. This is the ratio of the
maximum-to-minimum volume within the cylinder, between the piston and
cylinder head, containing a combination of fuel and air being
compressed. A high compression ratio results in more mechanical energy
that an engine can squeeze from its air-fuel mixture. High ratios
place increased oxygen and fuel molecules into a reduced space; thus,
they allow increased power at the moment of ignition. Compression
ratio is a single number that can be used to predict engine
performance.

Contact Breaker
The spring switch in the low-tension ignition circuit that controls
the timing of the spark in the high-tension circuit. Operated by a
cam, contact breakers are sometimes called points.

Contracting-Band Brake\
A brake in which a band is tightened around a rotation drum.

Counter Balancer
A weight in the engine that spins with the rpm to smooth out engine
vibrations.

Counter Steering
The input a motorcyclist gives to the handlebars in order to steer:
push the right handlebar to go right, or push the left handlebar to go
left.

Cradle Frame
Motorcycle frame with two tubes passing under the engine

Crankshaft
The main rotating shaft running through the length of the engine. As
the pistons move up and down, they work together to spin the
crankshaft. The rotating motion of the crankshaft is transmitted to
the gear cluster which is eventually used to rotate the rear wheel of
the motorcycle.

Crash Padding
A motorcyclist’s protective clothing, especially abrasion-resistant
and impact absorbing riding gear and helmet.

Crotch Rocket
A term some people use to describe a high performance sport-bike
motorcycle.

Cruiser
A style of motorcycle generally equipped with a low seat and pullback
handlebars. This style of bike predominantly stems from the
customizing of standard American motorcycles in the ’60s and ’70s.

Cush Drive
A transmission shock absorber, usually a rubber cushion in the rear
hub.

Custom Motorcycles
For many motorcyclists, the choices provided by the motorcycle
manufacturers do not provide enough variety to match the personalities
of the riders. For this reason, many customize their bikes or hire
customizers to do the work for them. Many of these customs are entered
in shows and win prizes. Customs can easily cost twice the selling
price of the original bike.

Cylinder
The tube-shaped sleeves that house the pistons in an engine and where
the fuel/air mixture is drawn for combustion.

Cylinder Head
A casting that caps the cylinder and contains the valves and
combustion chamber.

Darker Rally
Formerly known as “The Paris Dakar” and now as “The Lisbon Dakar
Rally,” or “Dakar Rally,” and also simply referred to as “The Dakar.”
It is an off-road competition comprised of cars, motorcycles, and
trucks held annually in January. The race is open to amateur and
professional entries and amateurs typically make up about eighty
percent of the participants. Founded in 1978, this endurance race runs
from Europe into Africa over several thousand miles along remote
routes that include hostile dunes, rocks and mud. The competition is
gruelling and a number of participants have died due to injuries
sustained in the race. Originally, the competition was from Paris,
France to Dakar, Senegal. However, due to politics and other factors,
the course, including origin and destination, have varied over the
years.

Damper
Means of controlling speed of movement of the steering or suspension.

Daytona Bike Week
A motorcycle event and rally held annually in Daytona Beach, Florida.
Approximately 500,000 people make their way to the rally area for the
10-day event. The festivities include motorcycle racing, concerts,
parties, and street festivals. The event is usually held on the first
full week of March and contends with the Sturgis Motorcycle Rally as
the most popular motorcycle rally in the United States.

Desmodromic
Valve gear operation in which the camshaft actively closes as well as
opens the valves.

Diamond Frame
Tubular frame design common until World War II and derived from the
bicycle layout. The engine cases often form part of the structure. In
profile it resembles a diamond shape

Die-Cast Controlled-Fill Aluminum Frame
Alloy frames featuring large one-piece sections constructed with a
high-vacuum mold process, reducing porosity and eliminating air
pockets that can result when pouring molten aluminum. These large
sections are then combined with a minimum of welds, or even bolted
together, to create the frame. The result is a lighter, more rigid,
more finely tuned frame of higher production quality.

Displacement
The size of the engine; specifically, the total volume found in the
cylinders. This is usually expressed in cc (cubic centimeters) or ci
(cubic inches). Generally, the larger the displacement, the more
powerful the motor.

Distributor
An internal combustion engine device which distributes high voltage in
the ignition system to the spark plugs, in the correct firing order.

DOHC: Double Overhead Cam
Designation for engines that utilize one camshaft to open the engine
intake valves and another to open the exhaust valves. This optimizes
valve timing for better performance.

Druid Forks
Side-sprung girder forks. Druid were the original makers.

Dry Clutch
As opposed to a “wet clutch” which is immersed in a cooling,
lubricating fluid, which also keeps the surfaces clean and gives
smoother performance and longer life, a “dry clutch,” is not bathed in
fluid that robs it of some energy. Since the surfaces of a wet clutch
can be slippery (as with a motorcycle clutch bathed in engine oil),
stacking multiple clutch disks can compensate for slippage. A Dry
Clutch is more like the clutch found on an automobile that separates
the engine from the transmission. There is a dry connection between
the engine and transmission.

Dry Sump
An oil lubrication system for four-stroke and two-stroke internal
combustion engines that incorporates an additional oil reservoir as
compared to a wet sump system. Rather than the oil being collected in
a conventional oil pan, or sump, for engine lubrication, oil is pumped
into a secondary reservoir and then pumped to the engine bearings,
effectively eliminating the oil starvation a wet sump system suffers
when subjected to high-performance acceleration, braking, and
cornering.

Dual Sport
Street legal motorcycles that provide varying levels of off-road
capabilities. Not as focused as pure off-road or pure street
motorcycles. Also known as dual-purpose.

Dump The Clutch
This is when a rider revs up the engine and quickly releases the
clutch, launching the bike off the line.

ECU: Engine Control Unit
Controls various aspects of an internal combustion engine’s operation.
ECUs control the quantity of fuel injected into each cylinder, with
each engine cycle, by monitoring the engine through sensors. ECUs also
control ignition timing and other peripherals. A special category of
ECUs are those which are programmable. These units do not have a fixed
behavior, but can be reprogrammed by the user.

EFI: Electronic Fuel Injection
A means of metering fuel into an internal combustion engine. EFI
replaces carburetors as a method to meter fuel. (See Fuel Injection).

Enduro
Off-road competition against the clock and usually over long
distances.

Engine Cut Off Switch
Usually located on the right handlebar switch housing, this switch
allows the motorcyclist to turn off the engine without removing his or
her hand from the handlebar. Also known as the “kill switch.”

Epicyclic Gear
A gear that operates around the circumference of another.

Ergonomics
The study of body posture, and the positioning of instruments, to
create a good human-to-machine interface. “Good ergonomics” refers to
how well a motorcycle fits a rider for its intended use.

Esses
A series of turns with quick left and right transitions.

Fairing
An enclosure on the front of the bike containing the windshield and
affording wind protection to the rider. Can be attached to the frame
and not move or be attached to the fork and move as the handlebars are
turned.

Farkles
Motorcycle enthusiasts may install accessories, called farkles (also
spelled farkels), to customize their machine. The word is generally
accepted to mean a combination of “function” and “sparkle”, hence,
farkle. The term is well known in the North American sport touring
community. Radar detectors, Global Positioning System receivers,
heated grips, and satellite radios are some of those farkles. Other
accessories could be aftermarket seats or bar risers, which make the
motorcycle more suitable for long miles.

Featherbed Frame
Famous Norton frame design by the McCandless brothers. It was
introduced in 1950 and was given its name by factory rider Harold
Daniell.

FIM: Fédération Internationale de Motocyclisme
The governing body of the international motorcycle sport. Originally
founded in 1904, it represents 90 national motorcycle federations that
are divided into six regional continental unions.
There are five motorcycle-racing disciplines that FIM covers,
encompassing 34 world championships and prizes:
1. road racing
2. motocross
3. trials
4. enduro
5. track racing (combining Grass Track and Speedway)
FIM is also involved in many non-racing activities that promote the
sport, its safety, and support relevant public policy.

Final Drive
Means of transmitting power to the driven wheel, usually by chain,
shaft, or belt.

Fore-and-Aft Flat Twin
A flat-twin engine mounted with cylinders positioned in line with the
frame.

Fork
The metal tubes that connect the front wheel to the motorcycle frame
via the triple tree. For handling, the front fork is a critical
motorcycle component as it allows the rider to steer. The fork, along
with its attachment points on the frame establish the critical
motorcycle geometry parameters of rake and trail, which in turn
contribute to wheelbase.

Four Stroke Engine
The most common engine design found in street motorcycles. It refers
to the number of times a piston moves up and down through each power
cycle.
1. A downward stroke brings in the fuel/air mixture
2. an upward stroke compresses the fuel/air mixture
3. a downward stroke results when that mixture is ignited and expands
(also known as the Power Stroke)
4. and finally an upward stroke expels the exhaust gases

Fuel Injection
A device that serves the same function as a carburetor, but uses
computer-controlled jets to inject atomized fuel and air into the air
stream going into the engine. (See EFI).

Gear Ratio
The gear ratio is the relationship between the number of teeth on two
gears that are meshed or two sprockets connected with a common roller
chain, or the circumferences of two pulleys connected with a drive
belt.

Girder Forks
Type of forks common on early machines, comprising rigid beams
attached to the steering head by parallel links that allowed movement.

Grand Prix Motorcycle Racing
Established in 1949 by the FIM, it is the oldest motorsport World
Championship that is still in existence. Competition is held in well
over a dozen countries in 5 continents. Grand Prix motorcycle racing
is currently divided into three distinct classes: 125 cc, 250 cc and
MotoGP. Grand Prix is French, meaning “Grand Prize.”

Greasy Track
A slippery racetrack.

Green Track
A new road-racing course with no rubber on the surface, which can be
slippery. “I had to be careful during that practice session because
the track was really green.”

Gypsy Tour
A motorcycle road event, usually several days in duration, in which
the participants travel through the countryside and stop at a
different destination each night. The implication is that you are
traveling without time or distance constraints.

Hairpin
A very slow, tight, sometimes 180-degree, turn.

Helical Gear
The leading edges of the teeth are not parallel to the axis of
rotation, but are set at an angle. Since the gear is curved, this
angling causes the tooth shape to be a segment of a helix. The angled
teeth engage more gradually than do spur gear teeth. This causes
helical gears to run more smoothly and quietly than straight-cut
gears. Helical gears also offer the possibility of using non-parallel
shafts.

High Side
A type of motorcycle crash that occurs when the rear wheel starts to
slide in a turn (sometimes due to a locked brake and the resulting
skidding tire), and then suddenly grips the pavement (which could
occur when letting off the brake) flipping the bike sideways. The name
derives from the side of the motorcycle that the rider will separate
from. If forcibly thrown over the bike, the rider is said to have
dismounted on the high side.
Riders are usually advised to do a lowsider rather than a highsider if
neither can be avoided. The highsider has the additional disadvantage
of the rider often being catapulted into the air by the sudden jerking
motion of the motorbike and the increased possibility of the motorbike
sliding behind the rider with the potential of striking him or her.
Because highside accidents are so much more deadly than lowside
accidents, the Motorcycle Safety Foundation recommends that if a rider
locks the rear brake, it should be kept locked until the motorcycle
comes to a stop. If necessary, locking the front brake to deliberately
cause a lowside is recommended.

Horsepower
A unit of measurement used to describe an engine’s strength.
Typically, the more horsepower an engine produces, the faster the
motorcycle can potentially go. The term “horsepower” was invented by
James Watt in 1782 to help market his steam engine and refers to the
power exerted by a horse in pulling.

Hub-Center Steering
One of several different types of front-end suspension/steering
mechanisms used in motorcycles. Hub-center steering is characterized
by a swingarm that extends from the bottom of the engine/frame to the
center of the front wheel instead of two forks.
The advantages of using a hub-center steering system instead of a more
conventional motorcycle fork are that hub-center steer separates the
steering, braking, and suspension functions. With a fork the braking
forces are put through the suspension, a situation that leads to the
suspension being compressed, using up a large amount of suspension
travel which makes dealing with bumps and other road irregularities
extremely difficult. Also, having the steering working through the
forks also causes problems with stiction, decreasing the effectiveness
of the suspension.
Its complicated assembly is only one of the reasons hub-center
steering is implemented in relatively few motorcycle models. The
telescopic fork steering system is much more commonly used.

Ignition Timing
The process of setting the time that a spark will occur in the engine
combustion chamber (during the power stroke) relative to piston
position or crankshaft rotation. Setting the correct ignition timing
is crucial in the performance of an engine. The ignition timing
affects many variables including engine longevity, fuel economy, and
engine power. Modern engines that are controlled by an engine control
unit use a computer to control the timing throughout the engine’s RPM
range. Older engines that use mechanical spark distributors rely on
inertia (by using rotating weights and springs) and manifold vacuum in
order to set the ignition timing throughout the engine’s RPM range.

Knobbies
The type of tires used by supercross and motocross racers. These tires
have large square knobs of rubber tread that are designed and arranged
in various ways to best grab the dirt. Sometimes mechanics take knobby
tires and carve them even more with a hot tire cutter–in order to help
the tire pattern best match the terrain.

Low Side
A motorcycle crash that results from a wheel losing traction, allowing
the bike to fall sideways. The name derives from the fact that it is
usually the inward side that the motorcycle will fall on, or the side
that points downward in a curve, the low side. Riders are usually
advised to do a lowsider rather than a highsider if neither can be
avoided. The lowsider has the advantage of the motorcycle sliding
before the rider, placing it out of harm’s way.

Mag Alloy
Magnesium alloy, a strong lightweight metal used for many components,
particularly wheels.

Megaphone
An outwardly tapered high-performance exhaust.

Mesh Jacket
An open-weave, protective apparel for motorcycle riders that allows
air to circulate through the garment offering ventilation and cooler
riding for hot, summer temperatures. Most notably used in motorcycle
jackets, although also available as construction for protective
motorcycle pants.

Monocoque Frame
A motorcycle frame in which the structure is made as one unit from a
sheet material (ie alloy or steel). It may also include bodywork or
fuel container in the structure. A Grand Prix motorcycle racing
monocoque motorcycle was developed in 1967 by Ossa, a Spanish
motorcycle brand. Honda also experimented with a monocoque motorcycle
in 1979 with its NR500. More recently the Kawasaki Ninja ZX-14 sport
bike was introduced for the 2006 US model year with an aluminum
monocoque frame.

Motocross
Off-road motorcycle racing held on enclosed, rough circuits. Motocross
is derived from the French, and traces its origins to British
Scrambling competitions. The name “motocross” is a contraction derived
from the words “Motorcycle” and “Cross Country.” (Also known as MX or
MotoX).

MotoGP
The premier class of Grand Prix motorcycle racing. The sport combines
high-speed motorcycles, which feature revolutionary technology,
piloted by some of the most skillful riders in the world. It costs
millions of dollars to get a MotoGP bike on the track. The bikes are
purpose-built, racing machines – prototypes – that are neither
available for general purchase nor can they be legitimately ridden on
public roads. Engines for current MotoGP race bikes must be four-
strokes with no more than 800 cc’s.

Naked Bikes
Sport or standard motorcycles with minimum bodywork, fairings or
windshields. This is a motorbike in its most basic form. The emphasis
is on functionality and ergonomics rather than aerodynamic body panels
and exaggerated riding positions that are most common on sport bikes.

OHC: Overhead Camshaft
A camshaft in an internal-combustion engine that is mounted within the
cylinder heads, above the combustion chambers, and drives the valves
or lifters directly instead of using pushrods.

OHV: Overhead Valve
A type of piston engine that places the camshaft in the cylinder block
and uses pushrods or rods to actuate rocker arms above the cylinder
head to actuate the valves. Lifters or tappets reside in the engine
block between the camshaft and pushrods.
This contrasts with an overhead cam (OHC) design which places the
camshafts above the cylinder head and drives the valves directly or
through short rocker arms. In an OHC engine, the camshafts are
normally part of the cylinder head assembly, while in an OHV engine
the camshaft (rarely more than one) is part of the main engine block
assembly.
Also called “pushrod engine” or “I-head” engine.

Open Cradle Frame
Motorcycle frame without tubes running under the engine. The engine
unit bolts into place between the front downtube and the swingarm
pivot area as a semi-stressed or stressed member.

Open Frame
Motorbike frame layout with a low structure between the seat and the
steering head often associated with scooters. Also known as a Step-
Thru.

Over Square
An engine with a greater cylinder bore than piston stroke.

Parallel Twin
A two-cylinder engine configuration in which both cylinders are
mounted side-by-side and across the frame.

Pinion
A small gear

Pin It
To go full throttle: Reference to pinning the tachometer and/or the
speedometer needle all the way to the right of the gauge. “Coming out
of the last corner, I just pinned it and won.”

Pit Board
A large sign a mechanic writes on and shows to his rider as he goes
past. Pit board signs can be used to show a rider’s position, how far
he’s ahead or behind, to encourage him or even to remind him to
breathe.

Pit Lane
The lane on the inside of the track, usually adjacent to the main
straight, where riders come in to have quick work or tire changes on
their motorcycles.

Pits
Where the racing teams park their trucks and set up makeshift garages
to work on the bikes and house the riders.

Primary Drive
The system of transferring power from the motorcycle engine to the
gearbox. Usually achieved by chain or gear.

Racing Flags
Checkered Flag – First across wins: race over
Black Flag – Rider disqualified or problem with motorcycle
Green Flag – Race start signal, race in progress when all is “go”
Red Flag – Race stopped, sometimes to be restarted
White Flag – One lap left to race
Yellow Flag – Caution, do not pass if flag is waving
Yellow and Red Striped Flag – Caution, indicates debris, fluid or
hazard

Rear Sets
Racing-style footrests fitted towards the rear of the machine to allow
the rider to adopt a racing crouch.

Rocker Arm
A centrally pivoted lever that transmits the motion of the camshaft to
open and close the valves.

RPM: Revolutions Per Minute
A term used to describe how fast a motor is spinning. Also known as
“revs.”

Sipes
One of many small incisions on a tire’s surface for the purpose of
improving traction.

Slicks
Racetrack-only tires, so named because they have no tread at all, just
a smooth surface so that the maximum amount of rubber grips the
asphalt.

Slipper Clutches
Specialized clutches developed for racing motorcycles to mitigate the
effects of engine braking when riders would decelerate as they entered
corners. They are designed to partially disengage or “slip” when the
rear wheel tries to drive the engine faster than it would normally.
The engine braking forces in conventional clutches will normally be
transmitted back along the drive chain causing the rear wheel to hop,
chatter or lose traction. This is especially noted on larger
displacement four-stroke engines, which have greater engine braking
than their two-stroke or smaller displacement counterparts. Slipper
clutches eliminate this extra loading on the rear suspension giving
riders a more predictable ride and minimize the risk of over-revving
the engine during downshifts. Slipper clutches can also prevent a
catastrophic rear wheel lockup in case of engine seizure or
transmission failure. Generally, the amount of force needed to
disengage the clutch is adjustable to suit the application.

Spine Frame
A motorcycle frame with a single main structural member from which the
engine is suspended. Also known as a backbone frame.

Step-Thru
Motorbike frame layout with a low structure between the seat and the
steering head often associated with scooters. On early machines it was
commonly called an open frame.

Stoppie
A motorcycle trick in which the rear wheel is lifted and the bike is
ridden for a short period on the front wheel. Front brake control
during the stoppie is essential.

Stroke
Measurement of length of piston travel in the bore, usually expressed
in millimetres.

Subframe
Any auxiliary framework attached to the main body of a motorcycle
frame. Typically, this refers to the rear section of the frame which
supports the seat, etc. The principal purpose of using a subframe is
to isolate vibration and harshness from the rest of the frame.

Superbike
A high-performance sport bike with a big engine (generally 1000cc and
larger)

Supercharger
An air compressor used to force more air into the combustion chambers
of an internal combustion engine which allows it to burn more fuel and
results in more power. (Also known as a Blower). When the blower is
driven by exhaust gas instead of an air compressor the device is
called a turbocharger.

Supercross
Motorcycle racing sport incorporating high performance, off-road
motorcycles on artificially created dirt tracks that include obstacles
and steep jumps. Professional Supercross racing events are held within
large sports stadiums.

Suspension
The system of components that reduce the impact of surface bumps and
serves to keep the wheels in better contact with the road or ground,
thereby improving control and traction. A typical motorcycle
suspension includes a pair of fork tubes for the front, as well as a
swingarm with one or two shock absorbers for the rear suspension.

Swingarm
The one- or two-sided arm (often made of aluminum or steel) that
connects the rear wheel to the frame and moves up and down with the
rear suspension. A two-sided swingarm could be described as a pivoted
fork, as the wheel is supported at both sides.

Tachometer
A gauge that measures how fast an engine is spinning. The measurement
is usually expressed in revolutions per minute

Telescopic Forks
Front suspension system on a motorcycle comprised of two fork tubes
which contain coil springs. The tubes “telescope” up and down to
absorb road bumps. This is the most common form of motorcycle fork
commercially available.

Timing
Measurement of the exact instant when the valves open or close in an
internal-combustion engine, or when the spark occurs. It is normally
expressed in degrees or millimetres before TDC

Torque
A unit of measure describing the twisting force, or leverage, an
engine can exert on the rear wheel. Typically, an engine with a lot of
torque will have the potential to speed up faster at lower RPM’s.

Track Day
Organized events in which members of the public are allowed to ride
motorcycles around established racing circuits. Criteria for being
eligible to participate is usually the holding of a motorcycle licence
and the payment of a fee.

Trail
The distance from the front axle’s vertical position on the ground, to
the spot in front of it created by drawing a straight line from the
angle of the forks. (Compare Rake). Trail is often cited as an
important determinant of motorcycle handling characteristics.

Upside-Down Forks
Telescopic forks that are installed inverted compared to typical
forks. In this case the slider tubes are at the bottom and the heavier
bodies are at the top. This decreases the unsprung weight of the
motorcycle and improves its handling. Also known as inverted
telescopic forks.

Valves (Intake and Exhaust)
Poppet valves within a four-stroke cylinder head that open and close
to allow fuel/air into the combustion chamber, and open and close to
vent the burned gas. Four-valve cylinder heads can more efficiently
pump fuel/air in and pump spent gas out, increasing performance.

V-Twin
Two-cylinder engine layout in which the cylinders form a “V.”

Water Cooling
Also known as “liquid cooling,” this system includes a radiator and
fluid to dissipate heat. Liquid is constantly circulated between the
radiator and motorcycle engine cylinders when the engine is operating.
A small fan (controlled by a thermostat) has a cooling effect on the
liquid passing through the radiator. Water-cooled bikes are less
likely to overheat, compared to air cooled engines, especially when
traffic may be slow or jammed, which minimizes the heat transfer of
rapid air circulation that air cooling provides.

Wet Clutch
A clutch that contains many plates that are in the oil spray of the
transmission and the oil gets between the plates. The plates on wet
clutches have a tendency to stick together when the bike sits. So,
when you start the bike in the morning, before you put it in first
gear to move off, depress the clutch lever for about 30 seconds to
allow the oil on the plates to drain off and the plates to separate.
Otherwise, you’ll get a decided clunk and slight movement forward when
you put it in first.

Wet Sump
As part of the lubricating system of an internal combustion engine, a
wet sump is a built-in oil reservoir at the base of the engine. From
there oil is pumped into various engine bearings and then drained back
down to the sump.
A benefit of a wet sump, as compared to a dry sump, is its simple
internal design, using a single pump with no external reservoir or
connecting hoses or tubes which may leak. On the other hand a wet sump
is unsuitable for high-perfomance applications, such as racing through
corners, where the oil may slosh around inside the sump and briefly
deprive the system of oil which could damage the engine.

Wheelbase
The horizontal distance between the ground contact points of the front
and rear wheels. Wheelbase is a function of motorcycle frame length,
steering axis angle, and fork offset. Wheelbase has a major influence
on the longitudinal stability of a bike (along with the height of the
center of gravity). Short bikes are much more likely to perform
wheelies and stoppies and have the quickest handling characteristics.
On the other hand, a motorcycle’s straight-line stability improves
with longer wheelbase. For example, sport bikes have a shorter
wheelbase and tourers have longer wheelbases.

Wheelie
An act of raising the front wheel of a motorcycle off the ground and
keeping it in the air while continuing to ride the bike.

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March 15, 2010 by Kamal
Filed under: Bikes 

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Comments

2 Comments on Racing Glossary – A Must Know for the Beginners in Biking!

  1. 4mp4net on Wed, 17th Mar 2010 8:10 pm

    2. ??????? ????? ???? ?? ..

  2. arabic search on Thu, 29th Apr 2010 8:08 am

    3. Thank you so much for this beautiful Article

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