Tennis racket
The tennis racket is the play equipment for playing tennis . It is sometimes referred to as a racket . The racket consists of a frame, the face and a handle. The part of the frame that encloses the clubface is called the head, and the transition between the head and the handle is called the heart.
frame
material
Wooden frames were used until the 1980s, mostly layered from different types of wood to vary the stiffness . The first metal clubs hit the market in the 1960s. They consisted of aluminum or steel , later a combination of both metals. In the 1970s, glass fiber reinforced plastic (GRP) was also used, later carbon fiber reinforced plastic (CFRP), which has the great advantage of being both light and stiff. Many clubs are still made of CFRP today. Other materials such as ceramic , titanium and aramid fibers (Kevlar, Twaron ...) are also important in the frame construction. Piezo fibers are now also being built into frames so that so-called intelligent clubs can be constructed.
However, the effect of piezo fibers, liquid metals, titanium, etc. is controversial among many experts; they regard these techniques as pure "marketing noise". Titanium particles, for example, were often only found in the paintwork of the frame, underneath was pure graphite. The opinion of these experts is strengthened by the disappearance of the series advertised in this way, usually after the first season.
The strength and hardness of the frame are decisive for the strength of a racket. The harder the frame, the more kinetic energy it can give back to the ball. If the frame is thin and soft, the impact energy is absorbed and not returned to the ball as intended.
Around the turn of the century.
Tennis racket from Franjo Punčec , a Croatian tennis player from the 1930s.
Wooden tennis racket with bag from the 1970s.
Jimmy Connors with aluminum bat, 1978.
Current plastic racket, around 2015.
,_Bestanddeelnr_929-6576.jpg)
dimension
Tennis rackets cannot exceed a total length of 73.7 cm (29 inches) according to ITF rules, with the standard length being 68.6 cm (27 inches). The width is limited to 31.7 cm (12.5 inches). A tennis racket weighs between 280 and 350 g with the strings. For children and teenagers there are correspondingly shorter and lighter clubs that are around 43 to 68 cm long, depending on their body length.
| body length | Club length |
|---|---|
| ≤ 92 cm | 43 cm |
| 92-100 cm | 46 cm |
| 100-110 cm | 49 cm |
| 110-120 cm | 53 cm |
| 120-130 cm | 58 cm |
| 130-137 cm | 63 cm |
| 137-148 cm | 66 cm |
In the course of time, the clubface increased through the use of new materials in the frame. The different head sizes are often divided into four classes:
- Midsize (<97 sq inch / 625 cm²)
- Midplus (98-105 sq inch / 630-675 cm²)
- Oversize (106–115 sq inch / 680–740 cm²)
- Super oversize (> 116 sq inch / 750 cm²)
Professional players mostly use clubs with smaller head sizes because they allow better ball control. Rackets with a very large surface usually have a lot of power, ideal for inexperienced players who cannot draw their punch from a long swinging motion.
Clubface
The playing surface consists of strings that are stretched into the frame and are laid out like a chessboard. There are two fundamentally different strings:
- The natural gut string is made from cow gut . It is particularly elastic. The string is very expensive and is therefore used almost without exception by professionals today. Problems can arise in high humidity or rain, as the string swells up and is no longer playable.
- The synthetic string is manufactured industrially and consists mostly of nylon or polyester , but there are countless other constructions. The durability is very high and is therefore ideal for hobby players.
The strings are placed in the frame using a stringing machine . The rigidity of the string is a decisive factor for the playing characteristics . It indicates how much tensile force the string applies to the racket. The manufacturer's recommendations are in the range of 23 to 30 kg (often given in pounds ; about 50 to 66 lbs). The main strings are sometimes strung harder than the cross strings. Basically: The harder the racket is strung, the more control of the ball and the less power you have in the stroke. Over time, the covering loses its hardness and should therefore be replaced regularly.
To protect the string, a plastic eyelet tape is usually inserted into the holes in the frame from the outside.
How the main and cross strings run in the racket and where the string can be knotted is called the stringing pattern. Illustrations of the various models are available on the websites of most club manufacturers. The number of long and short sides is indicated directly on some clubs (e.g. 16 × 19 stands for 16 long and 19 short sides).
Each club face has an area in which it is possible to hit with maximum acceleration and accuracy, the so-called sweet spot .
Racket grip
The racket handle comes in several shapes and sizes. To grip a is Grip (Basic Grip) wound that adapts to the hand and absorbs perspiration. Most tennis players also use an overgrip, which is regularly replaced.
There are seven different grip strengths that represent the size of the grip. The grip strength must be selected according to the size of the hand:
| Grip strength | scope | |
|---|---|---|
| in mm | in inches | |
| L 1 | 105 | 4 1 ⁄ 8 |
| L 2 | 108 | 4 1 ⁄ 4 |
| L 3 | 111 | 4 3 ⁄ 8 |
| L 4 | 114 | 4 1 ⁄ 2 |
| L 5 | 118 | 4 5 ⁄ 8 |
| L 6 | 121 | 4 3 ⁄ 4 |
| L 7 | 124 | 4 7 ⁄ 8 |
balance
Depending on the location of the center of gravity of a club, a distinction is made between top-heavy, balanced and head-heavy clubs.
The balance can be adjusted. Special lead tapes are available for this, which are glued to the frame.
Web links
- Stringing tennis rackets
- Tennis racket databases: saitenforum.de (very extensive, also old models); Tennisschläger.info (current models)
Individual evidence
- ↑ ITF Tules of Tennis 2016. (pdf) p. 25 , accessed on January 4, 2016 (English).
- ↑ http://saitenforum.de/saiten_info.php Relationship between stringing hardness and impact properties.