Modern downhill bikes weigh between 14 and 19 kg (30 and 42
pounds), and usually feature full-suspension and frame geometries that lean
back farther (slacker geometry) than other mountain bikes. As of 2006, 203 mm
(8-inch) is the 'norm' for suspension travel however some commercially
available big mountain freeride bikes can have over 300 mm (12-inch).
Large-diameter 203–5 mm (8-inch) hydraulic disc brakes moderate speed. Downhill
bikes and freeride bikes are similar but there are some slight differences.
Downhill race bikes typically are much lower and have slacker head angles than
freeride bikes, so that the bike is more stable at speed and in corners.
Freeride bikes have a steeper geometry and a higher bottom bracket height, so
that they are better for balance and maneuverability, however freeride bikes
sometimes use single crown forks, which are shorter in travel length and
lighter than the dual crown forks often used by downhill riders, dual crown
forks usually have around 200 mm (8-inch) of travel, and single crown forks are
usually around 180 mm (7 in) maximum.
1. Body Armor
2. Full Face helmet
3. Neck Brace
-to reduce the risk (by bringing the head to a controlled stop)of neck and spinal injury.
Downhill biking (DH) is a time trial mountain biking event
held on a course with a net decrease in elevation. As the name of this
discipline implies, downhill races are held on steep, downhill terrain,
resulting in high speed descents and, most commonly, with extended air time off
jumps and other obstacles. A continuous course is defined on each side by a
strip of tape. The width of the course can vary greatly over the length of the
course, but it is typically between about 2m and 10m wide. Riders have one attempt
to reach the finish line in the shortest amount of time while remaining between
the tape. The rider must choose their path (or line) by compromising between
the shortest possible line and the line that can be travel at the highest
speed. If a rider leaves the course by crossing or breaking the tape, he must
return to the course at the point of exit. Riders start at intervals, often
seeded from slowest to fastest. Courses typically take two to five minutes to
complete and winning margins are often less than a second. Riders are timed
with equipment similar to that used in Downhill skiing.
The sport
was further refined throughout the 1800s, and many militaries adopted it in the
1900s.In the military, skydiving was originally intended to be a backup safety
mechanism for airmen. If a plane became disabled during flight, the pilot could
deploy a parachute to save his life. Intrepid pilots began to skydive
recreationally as well, and in many countries, further applications were
considered. Many modern militaries use skydiving for troop deployment, for
example. Wildfire fighters also skydive to reach remote sites, so that they can
be on the ground quickly.
The potential of skydiving as a recreational sport was also
quickly realized. Both women and men participated in the development and
refinement of it as a sport, and continue to do so. Sport skydiving is
characterized by performing with a sense of flair as well as safety. These
people also perform stunts in films and for product promotions. Group skydiving
is also often performed as a sport, as is wingsuit flying, a variation that
uses a specially designedflight
suitto more closely mimic the sense of flying.
Several
safety measures are taken to make skydiving as safe as possible. Skydivers
regularly check their gear to ensure that it is in good shape, and most
skydivers carry a backup parachute. In some cases, the backup will deploy
automatically if a skydiver reaches a certain altitude. Both primary and backup
parachutes are controlled with steering lines, allowing the skydiver to control
his or her descent. Internationally, several organizations promote safe
skydiving, offering classes and certifications in the sport.
For
people who want to experience skydiving for themselves, numerous companies
around the world offer opportunities. In general, people take tandem jumps
their first few times out, so that they can learn the basics before taking over
on their own. Good training also involves ground schooling as well, to make
sure that the skydiver is safe, secure, and ready for a solo. Some companies
also offer standalone skydiving experiences for people who just want to try it
out.
Skydiving is a sport in which participants jump or fall fromaircraftat altitude. They can perform an assortment of aerial maneuvers
before deploying aparachuteto slow their descent, allowing them to come gently to rest on the
Earth below. The sport is also known as parachuting, in a reference to that
vital piece of safety equipment. People at different levels of physical fitness
can participate in skydiving, as long as they are ready for an adrenalin-packed
sport which can be both terrifying and exhilarating.
The
roots of the sport are actually much older than many people realize. Several medieval
inventors developed rudimentary equipment which could have potentially been
used for skydiving activity, and in 1797, Andre Jacques Garnerin jumped from a
hot air balloon with a parachute, marking the first incident of truly modern
skydiving
"Bungy Trampoline" uses, as its name suggests, elements from bungy and trampolining. The participant begins on a trampoline and is fitted into a body harness, which is attached via bungy cords to two high poles on either side of the trampoline. As they begin to jump, the bungy cords are tightened, allowing a higher jump than could normally be made from a trampoline alone.
Catapult
In "Catapult" (Reverse Bungee or Bungee Rocket) the 'jumper' starts on the ground. The jumper is secured and the cord stretched, then released and shooting the jumper up into the air. This is often achieved using either a crane or a hoist attached to a (semi-)perma structure. This simplifies the action of stretching the cord and later lowering the participant to the ground.
Twin Tower
"Twin Tower" is similar with two oblique cords. There are two towers, each with a cord leading the jumper. When the cords are stretched the jumper is released and shoots straight up.
"Bungee Running" involves no jumping as such. It merely consists of, as the name suggests, running along a track (often inflatable) with a bungee cord attached. One often has a velcro-backed marker that marks how far the runner got before the bungee cord pulled back. This activity can often be found at fairs and carnivals and is often most popular with children.
Bungee jumping off a ramp. Two rubber cords - the "bungees" - are tied around the participant's waist to a harness. Those bungee cords are linked to steel cables along which they can slide due to stainless pulleys. The participants bicycle, sled or ski before jump.
SCAD diving is similar to bungee jumping in that participant is dropped from a height, but in this variation there is not a cord, instead the participant falls into a net.
The word "bungee" originates from West Country
dialect of English language, meaning "Anything thick and squat", as
defined by James Jennings in his book "Observations of Some of the
Dialects in The West of England" published 1825. Around 1930, the name became
used for a rubber eraser. The word bungy, as used by A J Hackett, is "Kiwi
slang for an Elastic Strap". Cloth-covered rubber cords with hooks on the
ends have been available for decades under the generic name bungy cords.
In the 1950s, David Attenborough and a BBC film crew brought
back footage of the "land divers" (Sa: Naghol) of Pentecost Island in
Vanuatu, young men who jumped from tall wooden platforms with vines tied to
their ankles as a test of their courage and passage into manhood.A similar practice,
only with a much slower pace for falling, has been practised as the Danza de
los Voladores de Papantla or the 'Papantla flyers' of central Mexico, a
tradition dating back to the days of the Aztecs.
A tower 4,000 feet (1,200 m) high with a system to drop a
“car” suspended by a cable of “best rubber” was proposed for the Chicago World
Fair, 1892-1893. The car, seating two hundred people, would be shoved from a
platform on the tower and then bounce to a stop. The designer engineer
suggested that for safety the ground below “be covered with eight feet of
feather bedding”. The proposal was declined by the Fair’s organizers.
Futsal (Portuguese pronunciation futˈsaw) is a variant of
association football that is played on a smaller pitch and mainly played
indoors. Its name is a portmanteau of the Portuguese futebol de salão, which
can be translated as "hall football" or "indoor football".
During the sport's second world championships held in Madrid in 1985, the name
fútbol Sala was used. Since then, all other names have been officially and
internationally changed to futsal.
Futsal is played between two teams of five players each, one
of whom is the goalkeeper. Unlimited substitutions are permitted. Unlike some
other forms of indoor football, the game is played on a hard court surface
delimited by lines; walls or boards are not used. Futsal is also played with a
smaller ball with less bounce than a regular football.[1] The surface, ball and
rules create an emphasis on improvisation, creativity and technique as well as
ball control and passing in small spaces.
Players, equipment and officials
There are five players on each team, one of whom is the
goalkeeper. The maximum number of substitutes allowed is nine (FIFA change
2012), with unlimited substitutions during the match. Substitutes can come on even
when the ball is in play. If a team has fewer than three players in the team,
the match is abandoned.
The kit is made up of a jersey or shirt with sleeves,
shorts, socks, shinguards made out of rubber or plastic, and shoes with rubber
soles. The goalkeeper is allowed to wear long trousers and a different coloured
kit, to distinguish himself from the other players in the team and the referee.
He is also allowed to wear elbow pads because the surface is about as hard as a
tennis court or basketball court. Jewellery is not allowed, nor are other items
that could be dangerous to the player wearing the item or to other active
participants.
The match is controlled by the referee, who enforces the
Laws of the Game, and the first referee is the only one who can legally abandon
the match because of interference from outside the pitch. This referee is also
assisted by a second referee. The decisions made by the referees are final and
can only be changed if the referees think it is necessary and play has not
restarted. There is also a third referee and a timekeeper, who are provided
with equipment to keep a record of fouls in the match. In the event of injury
to the referee or second referee, the third referee will replace the second
referee.
Misconduct
Players are cautioned with a yellow card and sent off with a
red card.
A direct free kick can be awarded to the opposing team if a
player succeeds or attempts to kick or trip an opponent, jumps, charges or
pushes an opponent, or strikes or attempts to strike an opponent. Holding,
touching or spitting at an opponent are offenses that are worthy of a direct
free kick, as are sliding in to play the ball while an opponent is playing it
or carrying, striking or throwing the ball (except the goalkeeper). These are
all accumulated fouls. The direct free kick is taken where the infringement
occurred, unless it is awarded to the defending team in their penalty area, in
which case the free kick may be taken from anywhere inside the penalty area. A
penalty kick is awarded if a player commits one of the fouls that are worthy of
a direct free kick inside his own penalty area. The position of the ball does
not matter as long as it is in play.
An indirect free kick is awarded to the opposing team if a goalkeeper
clears the ball but then touches it with his hands before anyone else, if he
controls the ball with his hands when it has been kicked to him by a teammate,
or if he touches or controls the ball with his hands or feet in his own half
for more than four seconds. An indirect free kick is also awarded to the
opposing team if a player plays in a dangerous manner, deliberately obstructs
an opponent, prevents the goalkeeper from throwing the ball with his hands or
anything else for which play is stopped to caution or dismiss a player. The
indirect free kick is taken from the place where the infringement occurred.
The beginnings of badminton can be traced to mid-18th
century British India, where it was created by British military officers
stationed there. Early photographs show Englishmen adding a net to the
traditional English game ofbattledore and shuttlecock. The sport is related to
ball badminton, which originated in Tamil Nadu, and is similar toHanetsuki
which originated in Japan. Being particularly popular in the British garrison
town Poona (now Pune), the game also came to be known as Poona. Initially,
balls of wool referred as ball badminton were preferred by the upper classes in
windy or wet conditions, but ultimately the shuttlecock stuck. This game was
taken by retired officers back to England where it developed and rules were set
out.
Although it appears clear that Badminton House,
Gloucestershire, owned by the Duke of Beaufort, has given its name to the
sports, it is unclear when and why the name was adopted. As early as 1860,
Isaac Spratt, a London toy dealer, published a booklet, Badminton Battledore –
a new game, but unfortunately no copy has survived. An 1863 article inThe
Cornhill Magazine describes badminton as "battledore and shuttlecock
played with sides, across a string suspended some five feet from the
ground". This early use has cast doubt on the origin through expatriates
in India, though it is known that it was popular there in the 1870s and that
the first rules were drawn up in Poonah in 1873.
As early as 1875, veterans returning from India started a
club in Folkestone. Until 1887, the sport was played in England under the rules
that prevailed in British India. The Bath Badminton Club standardized the rules
and made the game applicable to English ideas. J.H.E. Hart drew up revised
basic regulations in 1887 and, with Bagnel Wild, again in 1890. In 1893, the
Badminton Association of England published the first set of rules according to
these regulations, similar to today's rules, and officially launched badminton
in a house called "Dunbar" at 6 Waverley Grove, Portsmouth, England on
September 13 of that year. They also started the All England Open Badminton
Championships, the first badminton competition in the world, in 1899.
The International Badminton Federation (IBF) (now known as
Badminton World Federation) was established in 1934 with Canada, Denmark,
England, France, the Netherlands, Ireland, New Zealand, Scotland, and Wales as
its founding members. India joined as an affiliate in 1936. The BWF now governs
international badminton and develops the sport globally.
While initiated in England, competitive men's badminton in
Europe has traditionally been dominated by Denmark. Asian nations, however,
have been the most dominant ones worldwide. Indonesia, South Korea, China, and
Malaysia along with Denmark are among the nations that have consistently
produced world-class players in the past few decades, with China being the
greatest force in both men's and women's competition in recent years.
Playing court dimensions
Badminton court, isometric view
The court is rectangular and divided into halves by a net. Courts are usually marked for both singles and doubles play, although badminton rules permit a court to be marked for singles only. The doubles court is wider than the singles court, but both are of same length. The exception, which often causes confusion to newer players, is that the doubles court has a shorter serve-length dimension.
The full width of the court is 6.1 metres (20 ft), and in singles this width is reduced to 5.18 metres (17 ft). The full length of the court is 13.4 metres (44 ft). The service courts are marked by a centre line dividing the width of the court, by a short service line at a distance of 1.98 metres (6 ft 6 inch) from the net, and by the outer side and back boundaries. In doubles, the service court is also marked by a long service line, which is 0.76 metres (2 ft 6 inch) from the back boundary.
The net is 1.55 metres (5 ft 1 inch) high at the edges and 1.524 metres (5 ft) high in the centre. The net posts are placed over the doubles sidelines, even when singles is played.
The minimum height for the ceiling above the court is not mentioned in the Laws of Badminton. Nonetheless, a badminton court will not be suitable if the ceiling is likely to be hit on a high serve.
Equipment
Badminton racquets
Racquets
Badminton racquets are lightweight, with top quality racquets weighing between 70 and 95 grams (2.4 to 3.3 ounces) not including grip or strings. They are composed of many different materials ranging from carbon fibre composite (graphite reinforced plastic) to solid steel, which may be augmented by a variety of materials. Carbon fibre has an excellent strength to weight ratio, is stiff, and gives excellent kinetic energy transfer. Before the adoption of carbon fibre composite, racquets were made of light metals such as aluminium. Earlier still, racquets were made of wood. Cheap racquets are still often made of metals such as steel, but wooden racquets are no longer manufactured for the ordinary market, because of their excessive mass and cost. Nowadays, nanomaterials such as fullerene and carbon nanotubes are added to rackets giving them greater durability.
Strings
Badminton strings are thin, high performing strings in the range of about 0.62 to 0.73 mm thickness. Thicker strings are more durable, but many players prefer the feel of thinner strings. String tension is normally in the range of 80 to 160 N (18 to 36 lbf). Recreational players generally string at lower tensions than professionals, typically between 80 and 110 N (18 and 25 lbf). Professionals string between about 110 and 160 N (25 and 36 lbf). Some string manufacturers measure the thickness of their strings under tension so they are actually thicker then than specified when slack. Ashaway Micropower is actually 0.7mm but Yonex BG-66 is about 0.72mm. It is often argued that high string tensions improve control, whereas low string tensions increase power. The arguments for this generally rely on crude mechanical reasoning, such as claiming that a lower tension string bed is more bouncy and therefore provides more power. This is in fact incorrect, for a higher string tension can cause the shuttle to slide off the racquet and hence make it harder to hit a shot accurately. An alternative view suggests that the optimum tension for power depends on the player the faster and more accurately a player can swing their racquet, the higher the tension for maximum power. Neither view has been subjected to a rigorous mechanical analysis, nor is there clear evidence in favour of one or the other. The most effective way for a player to find a good string tension is to experiment.
Grip
The choice of grip allows a player to increase the thickness of his racquet handle and choose a comfortable surface to hold. A player may build up the handle with one or several grips before applying the final layer.Players may choose between a variety of grip materials. The most common choices are PU synthetic grips or towelling grips. Grip choice is a matter of personal preference. Players often find that sweat becomes a problem; in this case, a drying agent may be applied to the grip or hands, sweatbands may be used, the player may choose another grip material or change his grip more frequently. there are two main types of grip: replacement grips and overgrips. Replacement grips are thicker, and are often used to increase the size of the handle. Overgrips are thinner (less than 1 mm), and are often used as the final layer. Many players, however, prefer to use replacement grips as the final layer. Towelling grips are always replacement grips. Replacement grips have an adhesive backing, whereas overgrips have only a small patch of adhesive at the start of the tape and must be applied under tension overgrips are more convenient for players who change grips frequently, because they may be removed more rapidly without damaging the underlying material.
Shuttlecocks with feathers
A shuttlecock with a plastic skirt
Shuttlecock
Main article: Shuttlecock
A shuttlecock (often abbreviated to shuttle; also called a birdie) is a high-drag projectile, with an open conical shape: the cone is formed from sixteen overlapping feathers embedded into a rounded cork base. The cork is covered with thin leather or synthetic material.
Synthetic shuttles are often used by recreational players to reduce their costs as feathered shuttles break easily. These nylon shuttles may be constructed with either natural cork or synthetic foam base, and a plastic skirt.
Shoes
Badminton shoes are lightweight with soles of rubber or similar high-grip, non-marking materials.Compared to running shoes, badminton shoes have little lateral support. High levels of lateral support are useful for activities where lateral motion is undesirable and unexpected. Badminton, however, requires powerful lateral movements. A highly built-up lateral support will not be able to protect the foot in badminton instead, it will encourage catastrophic collapse at the point where the shoe's support fails, and the player's ankles are not ready for the sudden loading, which can cause sprains. For this reason, players should choose badminton shoes rather than general trainers or running shoes, because proper badminton shoes will have a very thin sole, lower a person's centre of gravity, and therefore result in fewer injuries. Players should also ensure that they learn safe and proper footwork, with the knee and foot in alignment on all lunges. This is more than just a safety concern: proper footwork is also critical in order to move effectively around the court.