Optimal tension for maximum power?

Arak

Semi-Pro
I’m sure this has been discussed before, so please indulge me. I’m curious about what is the optimal tension that gives maximum power for different string materials. If I understand correctly, NG is more powerful at around 60lbs, while nylon prefers tensions in the lower 50s, and polyester even lower in the 40s. Is this correct?
 

esm

Hall of Fame
Don’t think there is a “set” criteria for that.
the powerful setup for Nadal won’t be the powerful setup for Fed... cos there are just too many variables.
 

TennisManiac

Hall of Fame
As stated above. There are so many variables. It all depends on stroke speed and technique. And of course what frame you're using as well.
 

Arak

Semi-Pro
As stated above. There are so many variables. It all depends on stroke speed and technique. And of course what frame you're using as well.
I fully understand that there are many variables, but if we take out the racket and technique from the equation, and only consider string characteristics?
 

socallefty

Professional
If you are talking about the relationship between string tension and power, here are some points to consider. You should read the book “Technical Tennis” to get more details.

- Lowering string tension by about 10 lbs causes only about a 1% increase in energy return and power. So, if you hit at 60mph with strings at 60lbs, you will hit only at 61 mph in the low forties. So, it doesn’t make much difference.
- However, lowering the string tension causes increased dwell time on the softer strong bed and this leads to a higher launch angle when you hit the ball - so, the same swing at lower tension will cause the ball to go deeper and the player will perceive the increased depth as increased power. Higher tensions cause a lower launch angle with the same swing which causes reduced depth and is perceived as less power.
- Different string materials don’t have significant differences in energy return, but have significant differences in launch angle. Softer strings like gut have higher launch angles than stiffer strings like poly which have lower launch angles for the same swing. Again, the same swing will therefore produce a deeper ball with gut and a more shallow ball with poly and therefore players perceive gut as having more power. Multis will have launch angles in between gut and poly and will be perceived as having medium power in between gut and poly. Advanced players like poly because they can swing harder and with the low launch angle, the ball still stays in the court while it may fly long with gut - poly also helps with greater spin production for fast swings due to something called the ‘Snapback effect’.

So, all strings will have more perceived power (more ball depth with same swing) at lower tensions. Softer strings will be perceived as having more power at the same tension than a stiffer string due to the increased ball depth.

The tension that is optimal for different strings has to do more with having enough control and comfort. Since gut produces the highest launch angle and more ball depth, it needs to be strung at relatively higher tensions compared to other strings to have enough control to keep the ball from flying long - many players prefer a range between 55-65 lbs. But, note that gut will have more perceived power and ball depth at lower tensions, but you might make too many errors long. Since gut is a comfortable soft string, players can string at high tensions and not feel like it is too harsh.

With poly, players will have enough control (less ball depth) even at tensions in the 40s and they prefer it to stringing higher because of the increased comfort and feel. Poly is stiff and can feel very harsh if you string at high tensions and also advanced players are more likely to break strings faster at high tensions which is another reason they might string poly below 50 lbs. Also, it should be noted that if you string poly too high, the launch angle might be so low that you make too many errors into the net and again players will want a good compromise tension which is usually between 40-50 lbs.

So, all strings will have higher launch angles, increased ball depth and increased perceived power at lower tensions and there is no optimal tension for maximum power with any string. The optimal tension for a particular string and racquet is more of a compromise between power, control, comfort and durability and it will vary depending on the player’s swing and what they are trying to achieve on the court. Hope this summary helps.
 
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Arak

Semi-Pro
If you are talking about the relationship between string tension and power, here are some points to consider. You should read the book “Technical Tennis” to get more details.

- Lowering string tension by about 10 lbs causes only about a 1% increase in energy return and power. So, if you hit at 60mph with strings at 60lbs, you will hit only at 61 mph in the low forties. So, it doesn’t make much difference.
- However, lowering the string tension causes increased dwell time on the softer strong bed and this leads to a higher launch angle when you hit the ball - so, the same swing at lower tension will cause the ball to go deeper and the player will perceive the increased depth as increased power. Higher tensions cause a lower launch angle with the same swing which causes reduced depth and is perceived as less power.
- Different string materials don’t have significant differences in energy return, but have significant differences in launch angle. Softer strings like gut have higher launch angles than stiffer strings like poly which have lower launch angles for the same swing. Again, the same swing will therefore produce a deeper ball with gut and a more shallow ball with poly and therefore players perceive gut as having more power. Multis will have launch angles in between gut and poly and will be perceived as having medium power in between gut and poly. Advanced players like poly because they can swing harder and with the low launch angle, the ball still stays in the court while it may fly long with gut - poly also helps with greater spin production for fast swings due to something called the ‘Snapback effect’.

So, all strings will have more perceived power (more ball depth with same swing) at lower tensions. Softer strings will be perceived as having more power at the same tension than a stiffer string due to the increased ball depth.

The tension that is optimal for different strings has to do more with having enough control and comfort. Since gut produces the highest launch angle and more ball depth, it needs to be strung at relatively higher tensions compared to other strings to have enough control to keep the ball from flying long - many players prefer a range between 55-65 lbs. But, note that gut will have more perceived power and ball depth at lower tensions, but you might make too many errors long. Since gut is a comfortable soft string, players can string at high tensions and not feel like it is too harsh.

With poly, players will have enough control (less ball depth) even at tensions in the 40s and they prefer it to stringing higher because of the increased comfort and feel. Poly is stiff and can feel very harsh if you string at high tensions and also advanced players are more likely to break strings faster at high tensions which is another reason they might string poly below 50 lbs. Also, it should be noted that if you string poly too high, the launch angle might be so low that you make too many errors into the net and again players will want a good compromise tension which is usually between 40-50 lbs.

So, all strings will have higher launch angles, increased ball depth and increased perceived power at lower tensions and there is no optimal tension for maximum power with any string. The optimal tension for a particular string and racquet is more of a compromise between power, control, comfort and durability and it will vary depending on the player’s swing and what they are trying to achieve on the court. Hope this summary helps.
I am aware of the higher launch angle, but also the TWU data seem to indicate that certain tensions seem to result in higher energy return percentages, and so do certain swing speeds. I know that energy return does not automatically translate into power, but they are certainly related.

Some multifilaments will produce highest energy returns at medium tensions and slow swing speeds for instance, and that correlates with my own experience, that I can control the ball better with NXT by swinging faster.

I’m not sure however if I string NG at mid tension that the lower energy return would be beneficial since the launch angle would be higher and directional control would be reduced.
 
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