String tension is one of the most underestimated settings in tennis. Two identical rackets, strung 3 kg apart, play completely differently. Here’s how to choose yours, including mains and crosses, with a full breakdown on natural gut.
The Principle: Power or Control
The basic rule is counterintuitive: the looser the string, the faster the ball travels. A slack string sinks deeper on impact, then rebounds like a trampoline.
- Low tension (around 20 kg or below): more power, comfort, and spin potential, but less control and precision.
- High tension (around 25 kg or above): more precision and control, but less power and greater strain on the arm.
On the professional circuit, tensions range from about 9 kg to over 40 kg—there’s no universal “right” tension.
What Tension Should You Choose?
Manufacturers indicate a recommended tension range on each racket’s frame, usually between 22.5 and 27 kg. This is the first benchmark to follow.
- To start, choose the middle of the range.
- For more power, lower the tension by about 1 to 1.5 kg next time you restring; for more control, increase it by the same amount.
- For recreational play, a reasonable tension between 23 and 27 kg helps maintain control and prevent injuries.
Tensions are sometimes given in pounds (lb): 1 kg is roughly 2.2 lb. So, 55 lb equals about 25 kg.
Mains and Crosses: Two Different Tensions
A stringbed consists of two sets of strings:
- The mains, vertical strings installed first. These do most of the work in generating spin;
- The crosses, horizontal strings that intersect with the mains.
A racket’s string pattern is listed in this order: a 16/19 pattern has 16 mains and 19 crosses.
The common practice is to tension the crosses slightly lower than the mains
- 1 kg less with natural gut or multifilament;
- 1 to 2 kg less with monofilament (polyester).
There are two reasons for this. Crosses are shorter than mains: at equal tension, they feel stiffer, and a lower tension balances the feel across the stringbed. Additionally, with a hybrid setup—where mains and crosses are made of different materials—each string needs its own tension for a uniform response.
Example: for a multifilament, 24 kg on the mains and 23 kg on the crosses.
String Type Affects Tension
At the same tension, a stiff string feels harder than a flexible one. Typical ranges vary:
- Natural gut, multifilament, or hybrid: around 21 to 25 kg;
- Monofilament: around 19 to 25 kg, usually on the lower side.
Avoid over-tensioning a flexible string—it would lose most of its advantages.
Natural Gut: The Premium Choice
Natural gut is the oldest type of string: Pierre Babolat developed it in the 1870s, initially from sheep intestines, then beef, as used today. Once the gold standard, it remains popular on the tour, often in hybrid setups.
Advantages
- Comfort: highly elastic, it absorbs vibrations better than any synthetic string. It’s a favorite among players prone to arm pain.
- Power: its elasticity naturally rebounds the ball.
- Touch: precise feel, especially on finesse shots.
- Tension retention: it holds tension and performance far longer than synthetic strings.
Disadvantages
- Price: €30 to €60 per set, depending on brand and treatment—several times the cost of synthetic strings.
- Durability: it wears faster than monofilament, especially for hard-hitting players with heavy topspin.
- Moisture: water can damage it, though modern gut is treated for better resistance.
- Spin: it grips the ball less than monofilament for heavy topspin shots.
What Tension for Natural Gut? Around 24 to 26 kg offers a good balance of comfort and control, or about 22 kg if you prioritize power. For context, Pete Sampras strung his gut between 32 and 35 kg, with a much heavier racket than today’s models.
The Hybrid Solution: Many players, including professionals, combine gut mains with monofilament crosses. This retains gut’s comfort and power while improving durability and control.
Tension Drops… Right After Stringing
The tension displayed by the stringing machine isn’t what your racket actually has: strings lose tension immediately after installation. A racket strung at 27 kg may only have 23 to 25 kg of real tension, depending on the stringbed, string type, and machine. It continues to lose tension over time, even without breaking.
When to Restring? The common recreational rule: as many times per year as you play per week. Play twice a week? Restring twice a year. With monofilament, which loses performance faster, restring more often.
Professional players also adjust tension for surfaces: many lower it by 1 to 2 kg when the clay season begins.
What About Your Arm?
High tension, especially with a stiff monofilament, transmits more shock to the arm. If you experience elbow or shoulder pain, a softer string (gut or multifilament) and lower tension can help. But persistent pain should be checked by a doctor or physiotherapist—equipment can’t replace medical advice.
In Summary
- Start with the middle of the range indicated on your racket.
- Tension crosses 1 kg lower than mains (1 to 2 kg lower with monofilament).
- Low tension for power and comfort, high tension for control.
- Natural gut offers the best comfort and tension retention but is expensive and sensitive to moisture.
- Restring at least as many times per year as you play per week.
To fine-tune your setup, a coach can advise you after watching your game. And to try a new racket or sell yours, check out the listings.
Sources
- Decathlon: What tension to choose for your tennis racket strings?
- Tennis Warehouse Europe: Tennis string guide
- Tennis Warehouse Europe: Technical terms (real tension)
- Tennis Warehouse Europe: Pros and cons of natural gut
- Mouratoglou: Why choose natural gut strings
- Tennis Companion: How to choose tennis strings
- Tecnifibre: What tension for your strings
- Tennis Majors: String tension and string pattern
- Racketpedia: Natural gut strings
