Also referred to as “static balance”, it is the point where a racquet will actually balance on a beam or other instrument and is not normally in the center of the frame’s length. If it is, that racquet is said to be “evenly balanced”. Most frames will fall into the other two categories: “head light”, with the majority of the weight in the handle, or “head heavy”, with the majority of the mass in the head. Balance can be expressed in three ways: inches or centimeters (measured from the butt of the racquet), or as “points” head heavy or head light (each point is 1/8” of length). Normally, heavier racquets will be balanced head light, while lighter ones will tend to be head heavy. Racquet balance can be altered with the placement of weight (usually lead tape) in the desired location, and can drastically affect racquet feel and performance.
Refers to the width of the racquet’s beams, and is an indicator of racquet stiffness and power. A racquet with wider beams will tend to flex less than one with more narrow beams (all else being equal), and as such will lose less energy to that flex and transfer more power to the ball. Cross section width is generally measured in millimeters and is normally termed in the following groups: Player’s frames will generally have beam widths of 22mm or less; Tweener racquets will usually have beam widths of 23-27mm, and Game Improvement frames will tend to have the highest cross sections of 28mm and above.
Refers to the actual strung area of the racquet’s head, and can be expressed in square inches or square centimeters. Head size is a determining factor in frame power and stability, as longer strings will have a higher “trampoline effect” (which can increase power). A wider head will have a larger “twist weight,” and will resist torque on off-center hits. A smaller head size can increase control (all else being equal) but will reduce sweet spot size, power, and torque resistance. There is no industry standard for head size classification, but a common range would be as follows:
Midsize: 85-95 square inches (550-615 square centimeters)
Mid Plus: 96-105 square inches (621-680 square centimeters)
Oversize: 106-115 square inches (686-744 square centimeters)
Super Oversize: 116 square inches and above (750+ square centimeters)
Refers to the circumference of the racquet handle. Most adult-size tennis racquets (27” and longer) available today have grip sizes ranging from 4 1/8”-4 5/8”.
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An indicator of how much effort is required to swing a racquet. Swingweight is a product of the racquet’s weight and balance point and is expressed in kilograms of weight per square centimeter of balance, or kg/sq. cm. A higher swing weight will generally indicate a racquet that, while harder to swing quickly, will have a higher power level. A frame with a lower swing weight will have less power but can be swung with more speed and less effort. Swingweight and mass are not necessarily the same, as a lightweight frame can have a head heavy balance point and thus a higher swing weight than a heavier frame with a head light balance. Swingweight can be increased by placing the weight (usually lead tape) at any point above where the player holds the racquet (normally 10cm above the racquet’s butt). The only way to decrease swing weight is by removing something from the frame: bumper guard, grip or racquet paint. Reducing string gauge may have a minimal effect on swing weight.
A measurement of the frame’s torsional stability, or its ability to resist twisting in the player’s hand on off-center hits. Twistweight is a product of the frame’s weight and the width of the racquet head and is expressed in kilograms of weight per square centimeter of width, or kg/sq. cm. Twistweight can only be increased by adding weight to the racquet (a racquet’s head cannot be made wider). The best place to add weight to increase twist weight would be at the widest point of the racquet head: the 3 and 9 o’clock positions. Larger-headed racquets will have a higher twist weight than smaller-headed ones of the same weight due to their wider hitting areas and are recommended for players with arm injuries (there are other factors to be considered as well).
A measurement of the frame’s ability to resist recoiling, or “kicking back” in the player’s hand, and is a primary factor in feel and stability on volleys. Recoil weight is a product of the racquet’s weight, balance, and swing weight, and is greatly influenced by balance: more weight in the handle of the racquet will produce a higher recoil weight, and more mass in the head will reduce it. A high recoil weight frame will be heavy and very head light, like most modern players’ frames. Head size is not an influencing factor for recoil weight.
The ability of the racquet strings to deform on ball impact, resulting in less energy loss and more stroke power, and is influenced by racquet head size, string tension, and string construction. Larger-headed racquets (longer strings) will provide a higher trampoline effect than a smaller-headed version at the same string tension. Lower string tensions will generally increase the trampoline effect, as will strings with a higher level of elasticity.
Normally associated with a frame’s ability to reduce shock and vibration before it reaches the player’s hand, and is commonly associated with comfort and injury prevention. Frames can dampen shock and vibration by high levels of weight, low flex levels, longer string length (larger head size), narrower beam widths, or by the manufacturer- installed dampening systems like Babolat Cortex, Wilson Amplifeel, or Pro-Kennex Kinetic technology. String vibration dampeners do not have a noticeable effect on dampening, but serve mostly to eliminate the sound (high-frequency vibrations) of the strings.
Refers to the area of the string face where the shot “feels” best, and the most power is generated, although there are actually three areas that could be called “sweet spots”. The Center of Percussion (COP) is the spot where the player will receive the smallest amount of shock as the ball is struck. The Node is the point where vibration is lowest, and the point of Maximum Coefficient of Restitution is the spot for maximum shot power, also being the lowest of the three “sweet spots” on the string face. These spots, while a product of the racquet’s weight, balance, length and head size, can be relocated with the application of weight (usually lead tape). By placing weight in the upper areas of the head, these spots can be raised, or they can be lowered by placing weight farther down on the racquet. String tension can also have an effect: lower tensions will increase sweet spot size, while higher ones will reduce it.
Refers to the process of altering a racquet to enhance or reduce certain playability characteristics. Most frame customization is done by adding weight (usually with lead tape, but melted silicone or hot glue could be injected into the handle) to various locations on the frame to increase power and/or stability. A frame can also be customized by changing handle size and/or shape with a heat-shrink sleeve, or by sanding a polyurethane foam handle to reduce its size. A butt cap can be changed or built up to give the player a more familiar feel if he’s changed brands of racquets.
A range of string tension the manufacturer has recommended for maximum playability of the racquet for the majority of players. It can be expressed in pounds or kilograms. This range is where the racquet will play the best for the majority of players according to the manufacturer’s testing. Some players may find it necessary to string below or above this range, but care should be taken when exceeding it.