Racket weight, U classes and balance: choosing for your game
What 3U, 4U and 5U really mean, how balance is measured, and which setup suits a net player or a power player.
The U classes are not the same for every brand
A higher U number means a lighter racket, but each brand sets its own limits. Victor publishes its ranges for the bare frame: 2U 90 to 94.9 g, 3U 85 to 89.9 g, 4U 80 to 84.9 g, 5U 75 to 79.9 g. Yonex describes its 4U as about 83 g, and Babolat gives the weight in grams instead of a U code, for example 74 g plus or minus 3 for a Satelite Gravity 74. Two rackets sold as 4U can therefore differ by a few grams: compare the grams, not the code.
Balance: where the weight sits
Balance is the point where the racket sits level on your finger, measured from the bottom of the handle. A head-heavy racket carries more weight toward the head, which helps power and tires the arm more; a handle-heavy one moves faster, and an even one is the all-rounder, as Babolat explains in its racket guide. For numbers, Babolat lists 300 mm plus or minus 5 for the Gravity 74, while Yonex calls its Astrox 88D Pro "head heavy" and stiff, for a doubles specialist at the back without giving millimetres. The usual cut-offs you read online (about 295 mm and above for head heavy, below 285 mm for light) come from retailers, not from a standard: brands do not agree on them.
Stiffness and frame
The shaft's stiffness is a separate choice. Yonex presents its Astrox 100ZZ as extra stiff, for intermediate to advanced players, and Victor calls the DriveX 9X the stiffest shaft of its range. A stiff shaft rewards a fast, clean swing and punishes a late one.
Our physical reasoning (not a sourced fact)
The harder a racket is to swing, the more its mass sits far from your hand. Moving weight toward the head makes the racket heavier to rotate, which adds power on a full swing and costs speed in quick exchanges at the net. A lighter racket with the weight toward the handle turns faster in the hand, which is why net players and fast doubles players often choose it. The price is less help on the clear and the smash, which then has to come from your technique.
Pairing racket and string
If you like fine strings for precision, a light, handle-heavy racket matches that touch-and-speed approach. If you play from the back with a long swing, a head-heavy racket and a stiffer shaft give more help, as long as your shoulder keeps up. Before buying, try a racket in the shop or borrow one: preference at the net is personal, and the sources say so too.