Handle counterweights can restore balance while swingweight stays higher

Adding mass at both ends can bring the balance point close to where it started while leaving a very different racquet to rotate. In the hypothetical example below, 5 g at the tip and another 5 g at the butt move a 300 g ready-to-play racquet from a 32.00 cm balance to 32.06 cm. Its swingweight rises from 320 to 337.32 kg·cm². A familiar balance reading can therefore accompany a substantial change in mass distribution.

This is the decision behind a common adjustment: head weighting improves the contact you wanted, but the racquet begins arriving late, so you add mass at the handle. That addition moves the centre of mass back towards your hand. To decide whether it addresses the actual problem, keep three separate entries in the notebook: total mass, balance location and swingweight about the stated measurement axis.

A balance measurement and a rotation measurement use distance differently

Balance locates the centre of mass. Tennis Warehouse University describes it as the point where the racquet rests level on a narrow support. Material near one end can balance material near the other through its distance from that support. The measurement describes where the combined mass acts when considering the racquet’s static balance.

Swingweight describes resistance to angular acceleration about a particular axis. An added piece of mass contributes according to its mass multiplied by the square of its distance from that axis. Squaring the distance is the key: a piece below the axis and a piece above it both add rotational inertia. Their contributions depend on distance, even when they pull the balance point in opposite directions.

Start comparisons with the same ready-to-play condition. Include the installed strings, replacement grip, overgrip, dampener and any existing added material. A catalogue’s unstrung mass and a reading from your fully equipped racquet describe different starting states. Weigh an actual accessory when you use it; the 5 g pieces in the example are chosen inputs for arithmetic.

Follow one hypothetical racquet through five configurations

The butt-only addition makes the balance more head-light: 32.00 cm becomes 31.48 cm. Total mass increases to 305 g and swingweight increases slightly to 320.50. The point mass placed exactly at the chosen 10 cm axis also moves the balance towards the handle, but contributes zero to rotation about that same axis. Location controls which change is large and which is small.

The tip-only addition sits 58 cm from the measurement axis, so its swingweight contribution is much larger. Adding the same 5 g at the butt afterwards shifts balance back towards the original reading. The completed combination weighs 310 g and has a swingweight of 337.32. Removing those two additions would return this idealised example to its starting numbers; adding the butt mass preserves the tip mass and its contribution.

The arithmetic explains why a counterweight leaves the increase in place

For the balance calculation, multiply each mass by its position from the butt, add those products, and divide by the new total mass. With 5 g at each end, the calculation is (300 × 32 + 5 × 68 + 5 × 0) / 310 = 32.0645… cm. The added masses place the centre of mass close to its starting location by distributing extra material on both sides.

For swingweight, an added point mass m in grams at location x in centimetres contributes (m / 1000) × (x − 10)² in kg·cm². At the tip this is 0.005 × 58² = 16.82; at the butt it is 0.005 × 10² = 0.50. Adding both contributions to 320 gives 337.32. The TWU worksheet reports the combined example as 310 g, 32.06 cm and 337.3 after its display rounding.

The two equations answer different questions. Balance uses mass and position to locate a centre; swingweight uses squared distance from a chosen axis to describe rotational inertia. When comparing two finished racquets, similar balance points can coexist with different amounts of material towards the ends. Record the axis and units with the swingweight number so that the comparison retains its meaning.

Choose the adjustment from the problem you observed

If your aim is a different balance point while retaining the added head mass, a handle addition is a direct way to explore that combination. You are accepting a higher total mass while keeping the head modification. Check whether the resulting setup remains manageable through the shots that matter to you, rather than judging it only while holding it still.

If the problem began when you added head mass and now concerns starting or redirecting the racquet, first compare with less of that added head material. This directly reduces the contribution you changed. Adding handle mass instead asks a different question: whether a more head-light balance feels useful despite retaining the extra rotational inertia.

Give the comparison a repeatable task. For example, alternate compact returns and deeper baseline swings at the same intended effort, noting late contact, depth and how often you rush the preparation. Treat this as a proposed observation routine. Leave the result column blank until you have played, and keep the setup labels precise enough to reconstruct either configuration.

Measure consistently before reacting to a small difference

TWU’s home method uses a racquet suspended by a string, the mass and balance, the suspension distance, and the time for ten full oscillations. A full oscillation is one trip out and back. Its instructions use a small movement of roughly 2.5–5 cm to either side, allow the motion to settle, and recommend averaging two or three timing runs. Consistent distances and counting are central to the method.

Record the spread of repeated readings as well as their average. A small estimated change deserves closer attention to measurement consistency before you attribute it to the accessory. Use the same suspension position, starting condition and counting convention each time. For a shop measurement, ask that both setups be measured on the same device and retain the actual readings.

The most useful finished note states what you kept and what you changed: the head material stayed in place, the handle gained a measured amount, balance moved towards the hand, and total mass increased. Add the rotation reading and your observed shot pattern. That record tells you whether to keep the new balance, reduce the head addition or return to the starting configuration.