Weight, balance, swingweight: the complete tuning guide
Updated: 3 days ago
Two frames of the same model, out of the same box at a retailer, do not feel the same. That is not an impression: four or five numbers differ from one unit to the next, and nobody has measured them.
Those numbers can be measured, computed and set — which is exactly why a Matcheur racquet is set to order, to a tenth of a gram, rather than shipped as it comes out of the mould. Manufacturing tolerance is not something to put up with: it is something to remove. Here is which ones, what they decide, and the formulas to work with them.
The quantities that decide
Mass
Total weight, strung. More mass: more stability at impact, less arm speed. Usual markers: under 285 g light, 285 to 305 g versatile, above 305 g heavy. These bounds locate you; they prescribe nothing.
Balance
The distance, in centimetres from the butt, of the point where the racquet tips on a pivot. At 33 cm and above the balance is head-heavy: more mass far from the hand, more inertia. At 32 cm it is neutral. Below that it is handle-heavy: more manoeuvrability.
Swingweight
The racquet's resistance to being rotated about an axis 10 cm from the butt, in kg·cm². It is the quantity players feel most and know least. Above 330: stability and transmitted energy. Below 310: manoeuvrability. It is swingweight, not mass alone, that decides what a stroke costs.
Twistweight
Resistance to torsion about the racquet's long axis. It decides nothing as long as you take the ball in the centre — and everything as soon as you do not. It rises with mass placed at 3 and 9 o'clock.
Recoilweight
What the arm absorbs on the way back. It follows from the first three quantities:
RW = SW − (Mass / 1000) × (Balance − 10)²
Mass in grams, balance in centimetres, SW in kg·cm².
MGR/I
The timing indicator: it compares the racquet's natural swing period with that of the arm carrying it. The exact formula is the one below — it often circulates in a simplified and incorrect form:
MGR/I = ((Mass / 1000) × 980.5 × Balance) / (SW + 20 × (Mass / 1000) × Balance − Mass / 10)
The weighting formulas
If you add a mass m, in grams, at a distance d from the butt, in centimetres:
New mass = mass + m
New balance = (mass × balance + m × d) / (mass + m)
ΔSwingweight = m × r² / 1000, with r = d − 10 (distance to the rotation axis)
Example, on a 300 g racquet balanced at 32 cm, length 68.5 cm. Add 5 g at 12 o'clock, so d = 68.5 cm. New balance = (300 × 32 + 5 × 68.5) / 305 ≈ 32.6 cm. ΔSW ≈ 5 × 58.5² / 1000 ≈ 17 points. Five grams, well placed, move swingweight by seventeen points — which is why nobody should weight a racquet by eye.
Where to put the mass, and what it produces
12 o'clock — maximum effect on swingweight and balance. The most powerful zone, and the easiest to overdose.
10 and 2 o'clock — a compromise: stability, with a moderate rise in swingweight.
3 and 9 o'clock — the only zone that really raises twistweight. This is where off-centre tolerance is won.
Under the grip — brings balance back towards the handle with almost no effect on swingweight. The counterweight that makes loading the head possible.
Buttcap — adds mass with almost nothing added to swingweight. It is the only place where MGR/I goes back up without touching swingweight.
Loading the head and compensating under the grip is the most useful combination of the lot: you gain stability without losing timing.
Doing it yourself, and the limit
The minimum kit is three objects: a scale accurate to a tenth of a gram, a pivot stand for balance, and something to add mass with — lead tape for the frame, tuning putty for the handle and the buttcap. Work in 1 to 2 g steps, and measure after each one.
The limit is clear: without a swingweight machine you set two quantities out of five and estimate the rest. The simulator on the Understand page computes all five in real time from your starting values — the fastest way to know where you are heading before gluing anything. And if the frame itself is not the right starting point, the configurator asks the six questions that decide the setup.
When to use the workshop
You have several racquets to match — that is measurement, not estimation.
You are aiming at a target MGR/I or a given twistweight.
You are preparing a season and want a documented starting point, reproducible from one racquet to the next.
In all three cases, a ProSetup tuning measures the values on your frame, adds the material and hands you the written record, before and after; matching applies the same method to two frames that need bringing into line.
A setup adds no level and corrects no stroke. It makes the racquet predictable — and that is the only thing one can honestly ask of it.
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