Fig. 4: Danish Youngster Victor Axelsen with his Adidas equipment.

2     Equipment

One of the reasons for the big improvement in the standard of world-class badminton is the improvement in the standard of the equipment. These developments mainly concern the racket, the stringing and the shuttlecocks. But clothing and shoes have also adapted to the demands of a performance sport, not forgetting special racket covers and sports bags that have evolved to meet top players' requirements.

2.1   The Racket

While in the 1980s rackets weighed between 100g and 130g, good rackets now weigh around 85g. However, rackets can still be strung to a hardness of up to 14kg. The parts of the racket are grip, the stringed area, the head and the shaft. From the origins of the sport until the 1970s, rackets were entirely made of wood. Rackets were kept in frames when they weren't being used to stop them becoming warped.

Only with the professionalization of the sport did Asian companies start experimenting with materials other than wood. To start with, the shaft and frame were made of light metal, steel, aluminum, and later of carbon-graphite (manmade fiber made from carbonized bitumen). This helped firstly to reduce the weight, and secondly to increase the stability of the whole racket. Today, materials like fiberglass and synthetic fibers (boron, graphite, Kevlar® and Magan Beryllium®) are also used. The materials have a very high resilience and are significantly firmer than steel, but most importantly have greater elasticity. Rackets also no longer consist of separate parts, but the head and shaft of the more expensive rackets are of one-piece construction.

The above materials make the rackets lighter and more flexible. In particular the elastic shaft allows the player to hit the shuttle with more whipping power, allowing him to hit the shuttlecock harder and faster, but the flexibility of the racket head is more of an impediment as it reduces stroke precision. The rule of thumb is: the harder the frame, the more accurate the strokes.

Expensive rackets are characterized by low torsion (torsional rigidity of the shaft). This is measured by to what extent the racket head turns left or right around the longitudinal axis of the shaft. If the player hits the shuttle not with the center but with the edge of the racket, it can be returned equally as well by a racket with low torsion as a shuttle that is hit with the center of a cheaper racket.

Another property of the racket that influences the play quality is balance. There are head and grip-heavy as well as balanced rackets on the market. Basically, head-heavy rackets offer greater acceleration in the smash, while grip-heavy models are better suited to defensive play, as they allow for greater accuracy. Balanced models are a compromise between the above. You can test which category a racket falls into by balancing it on your index finger at the point where the shaft joins the head.

Fig. 5: Isometric head shape

Fig. 6: Rounded head shape

Even the shape of the racket head has been experimented with, as the rules only stipulate a maximum size, i.e. the whole racket frame should not be longer than 68 cm (26.8 inches) and wider than 23 cm (9 inches). As far as the stringing is concerned, the maximum is 28 cm (11 inches) x 22 cm (8.7 inches). The traditional racket head is oval in shape to promote good shuttle acceleration, instead of the drop shaped head of the early days of the sport. An isometric head shape is also common, in which the head is rounded at the top, thus increasing the optimal hitting area, the so-called sweet spot.

Tip 1 Beginners should start off with a more robust racket that is often composed of several parts. A good such beginners' racket costs around $70-90. Stable rackets are particularly recommended for novices if they like playing doubles. Their lack of technical and tactical understanding often leads to accidental racket clashes.

Tip 2 In training and in particular in competition, a player should have at least two rackets with him. These rackets should be used alternately so that they are "broken in" and the player does not have to waste time getting used to them during a match.

Tip 3 The grip diameter can be regulated with grip tape. Players with big hands usually have thick grips, which they create by winding two or three grip tapes on top of each other in order to obtain the desired diameter.

Tip 4 New rackets have grips made of synthetic material or leather. Accomplished players who tend to have sweaty palms wind a non-slip grip tape made of rubber or terry cloth around the original tape. The terry cloth tape becomes worn out after a certain time and must be replaced.

Tip 5 Tournament players should always have a replacement grip tape handy in case it needs to be replaced urgently.

2.2   Stringing

The type and hardness of racket stringing is an important factor in badminton that affects shuttlecock flight and can cause acceleration, control and effort to vary considerably. Strings are an average of about 0.7-0.85 mm thick and may be made of synthetic material or gut.

Elite players used to swear by natural gut strings made of cow or sheep gut, but they are now becoming less common as the quality of synthetic strings has improved more and more. Gut strings are characterized by high elasticity and allow the player to play with great sensitivity and outstanding shuttle acceleration. However, they are more expensive than comparable synthetic strings and less durable, as they can be damaged by external influences like temperature and air humidity.

Synthetic strings may consist of one strand (polyester) or of several fibers (multifilament nylon strings), and each type is suited to a different type of game, such as sensitive or powerful. The durability also varies according to the manufacturing process. One of the highest-profile companies in this field is the American firm Ashaway, which started producing surgical thread and fishing lines more than 180 years ago in the Boston area. They have been developing badminton and squash strings for about 60 years.

A compromise must be found between acceleration and shuttle control in the stringing hardness. A good rule of thumb is: the harder the tension, the greater the control and shuttle security, at the expense of acceleration. Beginners and experienced match players should choose a hardness of around 7.5-10 kg (16.5-22 pounds) in order to obtain good durability. Only pros choose hardnesses of between 11 and 14 kg (24 and 31 pounds). Their good technique and strength allows them to compensate for these weaknesses. The strings often break when the stringing is this hard if the shuttle is hit at the edge of the racket instead of cleanly in the middle of the racket.

Tip 1: After the game, rackets should be put into a racket cover so that the stringing is not damaged by climatic conditions.

Tip 2: With regular training once or twice per week, a racket should be restrung approx. every 6 months, even if it is not broken, as the regular tension decreases over time, thus affecting stroke precision.

Tip 3: If a training racket string breaks, the racket can be repaired with a repair string. This should not be done more than once, as the broken string has already reduced the regular tension of the stringing anyway.

Tip 4: If a match racket string breaks, it is advisable to immediately cut the other strings with scissors. This is particularly done by pros with a high stringing hardness in order to stop the racket frame from becoming warped.

Tip 5: Players with 'tennis elbow' can play with a soft, nylon stringing to relieve elbow pain. They should seek expert advice as to the right strings to buy.

2.3   The Shuttlecock

Fig 7: Shuttlecock with 16 goose feathers.

The size and weight of the shuttle (or shuttlecock; in the US also called Birdie) are specified in the rulebook (see chapter 20). There are two different types: plastic shuttles or those made of natural goose and duck feathers. While the stringing industry has managed to virtually replace natural products with synthetic ones, this is not the case for shuttles. Only natural shuttles are used in elite badminton, which, although more expensive and less durable than plastic ones, have much better flight qualities.

Fig. 8: In the Victor shuttlecock factory in Nanjing in China, the distance between each individual feather is checked by hand.

The manufacturing of natural feather shuttles is extremely...