Split tension: what is the optimal mains/crosses tension difference?

#1
a starting point on a 16/19 racquet would be to assume the crosses should be strung with sixteen nineteenths (16/19)X the tension of the mains. That way the total horizontal force applied by the 19 crosses will equal the total vertical force applied by the 16 mains. (Less main strings) X (higher mains tension) = same total force.
By the 16/19 ratio the mains should be strung 8-10 pounds higher than the crosses. But why dont people use that dramatic of a tension split?
Why do most splits only differ by 2-3 pounds?
 
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#3
I'm at prestretched 70/50 full poly in one of my main racquets, and prestretched 90/50 kevlar/zx in the other. Both 18x20 95.

I max out the tension in the mains (whatever the string can handle), then adjust the cross tension to taste. Racquets perform much better all-around, IMO (better combination of spin and launch angle control), when mains are much tighter than crosses.
 
#4
Depends on the strings used, and the racket. Yonex looks at it similar to how you look at it--the crosses are shorter, so they recommend a 5% drop in tension for the crosses. Some people will tell you that there is friction loss when stringing the crosses. The friction occurs when the cross string is tensioned under and over the main strings. If you use a stringing tension meter, you'll find that strung at equal tension, the crosses will read sometimes as much as 20# lower than the mains. People will point to a racket becoming more round when removed from the machine, so the mains must be tighter than the crosses to make the head shorter and wider. Also, some strings are a lot stiffer than others, so they won't deflect from straight as much a softer string would. That's why many poly strings are being strung in the high 40s- low 50's, where older, pre-poly rackets had stringing recommendations of up to 70#. Finally, I think the racket comes into play too. A racket like, say a Head Radical, tends to shorten/get wider when the mains and crosses are strung at equal tension. To remedy this, I've found that if I string the crosses 5-8# tighter, the head doesn't get shorter and wider. Only experience can tell you which racket this works with. Not really a definitive answer on what to do, just different theories on why some people do what they do with hybrids.
 

drak

Professional
#7
I like 62/47 gut mains/Revolve cross in my TC100. IMO enhances snapback and spin. When I used Kev/Zx in a 98S I was at 66/46 plus or minus a bit.
 
#8
Q
Depends on the strings uSed, and the racket. Yonex looks at it similar to how you look at it--the crosses are shorter, so they recommend a 5% drop in tension for the crosses. Some people will tell you that there is friction loss when stringing the crosses. The friction occurs when the cross string is tensioned Under and over the main strings. If you use a stringing tension meter, you'll find that strung at equal tension, the crosses will read sometimes as much as 20# lower than the mains. People will point to a racket becoming more round when removed from the machine, so the mains must be tighter than the crosses to make the head shorter and wider. Also, some strings are a lot stiffer than others, so they won't deflect from straight as much a softer string would. That's why many poly strings are being strung in the high 40s- low 50's, where older, pre-poly rackets had stringing recommendations of up to 70#. Finally, I think the racket comes into play too. A racket like, say a Head Radical, tends to shorten/get wider when the mains and crosses are strung at equal tension. To remedy this, I've found that if I string the crosses 5-8# tighter, the head doesn't get shorter and wider. Only experience can tell you which racket this works with. Not really a definitive answer on what to do, just different theories on why some people do what they do with hybrids.
Are you sure that the crosses naturally lose tension compared to the mains right after stringing? If you started with the crosses and finished with the mains would the trend be reversed? All my equally strung racquets feel just as tight on the crosses compared to the mains.
 
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#9
Depends on the strings used, and the racket. Yonex looks at it similar to how you look at it--the crosses are shorter, so they recommend a 5% drop in tension for the crosses. Some people will tell you that there is friction loss when stringing the crosses. The friction occurs when the cross string is tensioned under and over the main strings. If you use a stringing tension meter, you'll find that strung at equal tension, the crosses will read sometimes as much as 20# lower than the mains. People will point to a racket becoming more round when removed from the machine, so the mains must be tighter than the crosses to make the head shorter and wider. Also, some strings are a lot stiffer than others, so they won't deflect from straight as much a softer string would. That's why many poly strings are being strung in the high 40s- low 50's, where older, pre-poly rackets had stringing recommendations of up to 70#. Finally, I think the racket comes into play too. A racket like, say a Head Radical, tends to shorten/get wider when the mains and crosses are strung at equal tension. To remedy this, I've found that if I string the crosses 5-8# tighter, the head doesn't get shorter and wider. Only experience can tell you which racket this works with. Not really a definitive answer on what to do, just different theories on why some people do what they do with hybrids.
Also, in a 16/19 string pattern, the 19 crosses are pulling each side of the hoop about 15% harder force-wise than the mains are pulling the top off the hoop to the throat (if cross/main tension was equal). Are you saying the friction tension loss on the crosses accounts for this or even overcompensates for this? When you said 20# did you mean 20 pounds or 2 pounds?
 
#10
Q
Are you sure that the crosses naturally lose tension compared to the mains right after stringing? If you started with the crosses and finished with the mains would the trend be reversed? All my equally strung racquets feel just as tight on the crosses compared to the mains.
Another way to look at it is that the main strings are strung at reference tension. Then the crosses are strung and they displace the mains from their straight directions. As the mains are bent into weaves, they are lengthened and they tighten more. The crosses just get the reference tension from the tensioner. So it's the mains getting more tension rather than the crosses losing tension.
 
#11
Not true statement. Most that can happen is that mains and crosses equalize at ref tension if one piece. If 2 piece hybrid with mains > cross, mains could stabilize somewhat below orig ref tension and crosses are at ref tension, whatever that is. If 2 piece hybrid with mains < crosses, mains could stabilize above orig ref tension and crosses are at ref tension. Stable means as the frame comes off the machine. After 12 hours, differential string relaxation rates could leave tensions all over the place. Players who are familiar with their strings' behavior account for this when stringing or asking for a tension. [FWIW, this does not even address issues related to different stringer, different/same machine, speed, temperature, yada, yada.]

People seem to think that mains will increase tension as the crosses are weaved. That's a true statement, but that tension cannot go above the orig ref tension UNLESS the cross' ref tension is significantly higher than the mains' ref tension. If crosses are strung lower, overall tension will be somewhere between mains and crosses which is the desired 'tension.'

FWIW, if you use a CP tensioner, you can and should minimize the frictional tension losses. You can be really off using a LO, but there is no excuse if using a CP.

OP's statement is a hypothesis. Not very well thought out since manufacturers' stringing instructions do not seem to care about this issue. Only Yonex cared because of their square head shapes and Stringway with their Tension Advisor. Yonex no longer cares. Stringway says their method yields a frame that is the same length. I do not use their method and my frames' length are > 95% same before and after; ~ 99% with 1 mm. Only time it changes is due to differential tensions.
 
#12
a starting point on a 16/19 racquet would be to assume the crosses should be strung with sixteen nineteenths (16/19)X the tension of the mains. That way the total horizontal force applied by the 19 crosses will equal the total vertical force applied by the 16 mains. (Less main strings) X (higher mains tension) = same total force.
By the 16/19 ratio the mains should be strung 8-10 pounds higher than the crosses. But why dont people use that dramatic of a tension split?
Why do most splits only differ by 2-3 pounds?
Some do. I have strung the crosses 50lbs lower before and 20lbs less is fairly typical with low sw racquets.

This bored is stupid mostly about strings and uber dogmatic so its best to experiment on your own if you are wanting to do something different.
 
#15
Not true statement. Most that can happen is that mains and crosses equalize at ref tension if one piece. If 2 piece hybrid with mains > cross, mains could stabilize somewhat below orig ref tension and crosses are at ref tension, whatever that is. If 2 piece hybrid with mains < crosses, mains could stabilize above orig ref tension and crosses are at ref tension. Stable means as the frame comes off the machine. After 12 hours, differential string relaxation rates could leave tensions all over the place. Players who are familiar with their strings' behavior account for this when stringing or asking for a tension. [FWIW, this does not even address issues related to different stringer, different/same machine, speed, temperature, yada, yada.]

People seem to think that mains will increase tension as the crosses are weaved. That's a true statement, but that tension cannot go above the orig ref tension UNLESS the cross' ref tension is significantly higher than the mains' ref tension. If crosses are strung lower, overall tension will be somewhere between mains and crosses which is the desired 'tension.'

FWIW, if you use a CP tensioner, you can and should minimize the frictional tension losses. You can be really off using a LO, but there is no excuse if using a CP.

OP's statement is a hypothesis. Not very well thought out since manufacturers' stringing instructions do not seem to care about this issue. Only Yonex cared because of their square head shapes and Stringway with their Tension Advisor. Yonex no longer cares. Stringway says their method yields a frame that is the same length. I do not use their method and my frames' length are > 95% same before and after; ~ 99% with 1 mm. Only time it changes is due to differential tensions.
If manufacturers were as efficient as you say they are they would sell djokovics and murrays pro stocks to the public. Also, any cross stringing that deflects the mains is going to raise the mains tension. String doesnt stretch for free. Look at any racquet. The mains are significantly deflected, and forced to take a longer path than before the crosses were added. Also i dont know why you are calling what i said a hypothesis; 19 cross strings each pulling 50 pounds having a net force of 950 pounds pulling the sides of a racquet together and 16 mains at 50 pounds having a net force of 800 pounds pulling the tip and throat of the racquet together is simple physics.
 
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#16
I use about a 4 lb difference between my mains ( higher) and the crosses ( lower). EXCEPT if I am using a string that the manufacturer says to go a certain % lower. Then I use their recommendation. I have one racquet like that where the tension is strung at 60 #mains/48# crosses.
 
#17
Physics would say that an oval shape will redistribute the internal forces tension due to different number of mains and crosses. If they remained separated, then the hoop will be distorted significantly. I string my own and other clients. One parameter I want is same length before and after strings with same ref tension on mains and crosses. And I hit that target 99% of the time on 14x18, 16x15, 16x18, 16x19, 16x20, 18x16, 18x19 and 18x20. If you get a frame back from anyone that is 3-5 mm shorter when you specify same ref tension mains and crosses, then the stringer has technique issues.

My post said nothing about Pro stocks. You are putting words into my statements.

You also do not understand string behavior. Tension a main and clamp it. It will start to lose tension. So by the time crosses are woven, the mains are under ref tension. Cross are pulled at ref tension thereby raising the mains back towrads what ever ref tension is in the cross. The ref tension in the cross cannot raise the tension in the mains above the original ref tension. If it could, you would have a proverbial Perpetual Motion machine. Only exception is if the ref tension of cross >> ref tension of mains.
 
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Yoneyama

Professional
#18
You can't put a number on what the optimum is.. These discussions are always pointless endless loops of hypotheses. So many more factors go into it than just string pattern and length of strings. Guys like the Sergetti Sheet people would have the best "scientific/numbers-based" answer for "optimum", however the real answer is always going to be personal preference. Experiment with varying differentials between mains and crosses and you will find one you like eventually.
 
#19
Another way to look at it is that the main strings are strung at reference tension. Then the crosses are strung and they displace the mains from their straight directions. As the mains are bent into weaves, they are lengthened and they tighten more. The crosses just get the reference tension from the tensioner. So it's the mains getting more tension rather than the crosses losing tension.
Yes, but I suppose the crosses could lose some tension from the weaving friction.
 
#20
You also do not understand string behavior. Tension a main and clamp it. It will start to lose tension. So by the time crosses are woven, the mains are under ref tension. Cross are pulled at ref tension thereby raising the mains back towrads what ever ref tension is in the cross. The ref tension in the cross cannot raise the tension in the mains above the original ref tension.
But anyway the resulting tension for the mains will be higher than if the weaving did not happen.
 
#21
Fo me it is always the middle crosses that start to move first, so I am tempted to string them at bit higher. But I am not sure that is a valid reason/theory. I am aiming for a durable stringing, one that as well as possible retain playbility /feel after the first few hours of playing.
 

TripleB

Hall of Fame
#23
I think if the racquet head was perfectly round (or square) then you might could apply the 16x19 tension ratio but since it isn't I'm not sure it's advisable to keep that tension ratio.

Extremely interesting topic though!!!!

TripleB
 
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#24
Physics would say that an oval shape will redistribute the internal forces tension due to different number of mains and crosses. If they remained separated, then the hoop will be distorted significantly. I string my own and other clients. One parameter I want is same length before and after strings with same ref tension on mains and crosses. And I hit that target 99% of the time on 14x18, 16x15, 16x18, 16x19, 16x20, 18x16, 18x19 and 18x20. If you get a frame back from anyone that is 3-5 mm shorter when you specify same ref tension mains and crosses, then the stringer has technique issues.

My post said nothing about Pro stocks. You are putting words into my statements.

You also do not understand string behavior. Tension a main and clamp it. It will start to lose tension. So by the time crosses are woven, the mains are under ref tension. Cross are pulled at ref tension thereby raising the mains back towrads what ever ref tension is in the cross. The ref tension in the cross cannot raise the tension in the mains above the original ref tension. If it could, you would have a proverbial Perpetual Motion machine. Only exception is if the ref tension of cross >> ref tension of mains.
But you are implying that a force that deflects the mains and makes them take a longer path has no effect on the tension of the mains. How can you say that stretching a string doesnt raise tension, even if only slightly? Why would stretching a string lead to plastic deformation in some cases and elastic recoil in other cases?
 
#25
Perhaps the main reasons for stringing crosses lower are, there are more of them, the sides of the hoop are less curved (easier to bend) and the old reason that they are shorter.
Trying to even out tension between crosses and mains by stringing crosses higher (as I have done) might be futile, because it tightens mains by elongation (+weave).
 
#26
Good question. I used to play with more conventional 2lbs difference.

But right now I'm testing a mutli/poly hybrid with 55/40. I just took the tension from the full bed string job of each string and I have to admint, it plays pretty well.
 
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#27
Even when stringing the crosses, those crosses strung earlier will reduce in tension as other crosses begin to share some of the load.

As an example, if the 5th cross and 5th last cross were the same length and strung at the same tension, I think that the 5th cross would have a lower tension than the 5th last once all crosses are strung.

There are so many reasons why it doesn't make sense to string all strings with the same tension, or all main or crosses at the same tension.
 
#28
The mains string up 30-35% tighter than the crosses stringing mains and crosses at the same tension. I use 57/54-59/56 in a 16x19 with Gut/poly. For no reason other than it plays better for my game. Any more on the differential than 2-3lbs and I have a hard time hitting my spots on the serve. Creates more spin but at the cost of loss of control.
 
#29
My last experiment was to string the center 4 mains AND crosses one kilo tighter, to get a slightly firmer feel in the sweet spot, and perhaps a bit lower launch angle there (this for my 16/19 RF 97). I might go up to 6 mains and crosses.
 
#31
Yes. But I can't be bothered to change the tension for each string. Firming up the middle a bit, while retaining some elasticity, seems plausible to me. By the the way, I do a bit of progressive stringing allready, more or less inadvertantly. I do one piece. The mains knot lowers tension, which I try to duplicate on the other side. The first crosses are softened by doing two crosses at one time, and the cross knot lowers tension a bit in the other end.
Btw, I do not really understand the colours in the above. And I believe the improvement in sweetspot is wastly exaggerated. Although it perhaps is true for a fixed racket, racket twisting when hitting off center will reduce the effective sweet spot a lot (for one).
 
#32
Good question. I used to play with more conventional 2lbs difference.

But right now I'm testing a mutli/poly hybrid with 55/40. I just took the tension from the full bed string job of each string and I have to admint, it plays pretty well.
Can you give us a little more feed back on your interesting setup here.
What strings are you using? What racquet?. Does the high differential change the swingweight of the racquet? Overall benefit of the 15lb difference?
 
#34
Physics would say that an oval shape will redistribute the internal forces tension due to different number of mains and crosses. If they remained separated, then the hoop will be distorted significantly. I string my own and other clients. One parameter I want is same length before and after strings with same ref tension on mains and crosses. And I hit that target 99% of the time on 14x18, 16x15, 16x18, 16x19, 16x20, 18x16, 18x19 and 18x20. If you get a frame back from anyone that is 3-5 mm shorter when you specify same ref tension mains and crosses, then the stringer has technique issues.

My post said nothing about Pro stocks. You are putting words into my statements.

You also do not understand string behavior. Tension a main and clamp it. It will start to lose tension. So by the time crosses are woven, the mains are under ref tension. Cross are pulled at ref tension thereby raising the mains back towrads what ever ref tension is in the cross. The ref tension in the cross cannot raise the tension in the mains above the original ref tension. If it could, you would have a proverbial Perpetual Motion machine. Only exception is if the ref tension of cross >> ref tension of mains.
I reread your posts. You seem to be saying incompatable things. If crosses are strung with similar tension to mains, they will deflect the mains as much as the mains deflect the crosses. The mains tension should increase as a result, even if the crosses arent pulled any tighter than the mains. Just like making a bouncy ball out of rubber bands. The rubber bands wrap around eachother which raises the tension of each rubber band. Assuming the amount of string stretching/relaxation is proportional to rise in tension, the mains will relax to a lower tension then be displaced by the crosses which stretches them further and increases their tension right? The crosses will be strung after so they dont get new tension breathed into them like the mains did. Isnt the spring constant of a string proportional to how much it is stretched? And if so, how could the mains tension not be higher if it is pulled to the same tension and then stretched later, while the crosses are only pulled to the given tension?
 
#35
Whats the verdict on main/cross tension after equal string up? There have been answers all over the place and this thread needs more arguments made.
The simplest way to determine if mains and crosses are balanced is by measuring the frame length after stringing. If I string Multi main with Poly cross, with the cross being 3 lbs less I get no frame shortening. I have tried the crosses 10 lbs less but the frame shortens by about 3mm which upsets the swingweight. I prefer the frame in its original shape.
So I would like to say 3 lbs to 5lbs differential is ideal. But of course there are many others here that will disagree. Some are doing huge 40lbs differentials and use the frame warp as kind of a tensioned spring acting on the mains.
At the end of the day if you love to tinker with setups, you have to have a stringing machine, many reels of string and literally trial over and over many combos and tensions that you like best. Be prepared to cut out perfectly good string jobs and start again. Its all part of the fun of tennis.
 
#36
The mains string up 30-35% tighter than the crosses stringing mains and crosses at the same tension.
And if you were to string the crosses 30-35% tighter than the mains, it will deform the racket more etc., increasing the mains tension more, so you sort of never catch up (before breaking the racket perhaps). You will get closer though.
 
#38
Hybrid Strings:
i) with polyester or monofilament strings, you should keep your Luxilon monofilament strings at the same tension in the mains, and install the crosses 5-10% higher. Most people prefer an increase of 5%.
ii) If you currently are playing with gut strings, multifilaments, or synthetic gut, you should keep you normal tension on the crosses with your multifilament string, and install the mains 5-10% lower with a Luxilon Monofilament. Most people prefer a 10% drop in tension.

Currently when using the same string and cross the tensions should remain the same. When blending strings, ie polys and syn gut or gut, the poly should be 4 lbs less than the syn gut or natural gut. This can vary according to gauge of strings being used, but in general there is a 4 pound difference.

IMPORTANT: The next issue becomes fine tuning. Players need to pay attention to where the shots are landing when the ball is clearing the net in the red zone. (Again, no more than 2′ – 3′ in height). If the ball is not realizing the desired depth we suggest using the following formula to adjust the tension. To increase ball length reduce 2 pounds of tension for every yard (3 feet) of added length. If shots are too long, the reverse formula should be applied; increase tension 2 pounds for every yard you want to bring the shot in. These are guidelines that tend to be remarkably accurate in adjusting the tension to achieve desired ball length.


Sent from my iPad using Tapatalk
 
#39
Can you give us a little more feed back on your interesting setup here.
What strings are you using? What racquet?. Does the high differential change the swingweight of the racquet? Overall benefit of the 15lb difference?
Racquet: Yonex Duel G 330 - Pure racquet was exactly 330g, Basic Grip (Head Hydrosorb Pro 1.75mm) and then balanced out a tad headlighther from 310mm to 305mm.
Strings: Mains - Pro's Pro Gutex Ultra 1.30 mm. Crosses - Pro's Pro Plus Power 1.18 mm.
I didn't notice any difference in the swing weight.

I played with Gutex Ultra full bed before at 55lbs and with Plus Power full bed at 40lbs.
I felt GU was soft, good powered and arm friendly, but with the obvious problems in control and spin.
PP was quite the opposite: good control and spin, but harsh and low powered.

I read about this hybrid here on TTW (can't find the source right now), so thought I would give it a try (and Pro's Pro is cheap, so now worries about a potential bad result):
As overall benefit I feel like a get good mix of both full bed setups. Proper power, fair amount of control and spin and rather arm friendly. Biggest difference I noticed: my backhand slice (attack and defense) had superb depth control.

I really like it. Broke it within 3hrs. of match play though.
 
#40
The simplest way to determine if mains and crosses are balanced is by measuring the frame length after stringing. If I string Multi main with Poly cross, with the cross being 3 lbs less I get no frame shortening. I have tried the crosses 10 lbs less but the frame shortens by about 3mm which upsets the swingweight. I prefer the frame in its original shape.
So I would like to say 3 lbs to 5lbs differential is ideal. But of course there are many others here that will disagree. Some are doing huge 40lbs differentials and use the frame warp as kind of a tensioned spring acting on the mains.
At the end of the day if you love to tinker with setups, you have to have a stringing machine, many reels of string and literally trial over and over many combos and tensions that you like best. Be prepared to cut out perfectly good string jobs and start again. Its all part of the fun of tennis.
When I string using Sergetti on my 6 pt Stringer the final tension on all 6 pts feels the same as when I started.
When I string traditionaly, the side clamps are either loose or really hard to undo depending on the strings I use.
 
#41
When I string using Sergetti on my 6 pt Stringer the final tension on all 6 pts feels the same as when I started.
When I string traditionaly, the side clamps are either loose or really hard to undo depending on the strings I use.
Yeah seems excellent way to determine frame distortion. Not familiar with Sergetti stringing though.
 
#43
I am not saying if those numbers and picture above is faulty. But I am a science teacher, if I were to grade these x-y table and pic, I would say the picture did not communicate what those numbers means, no unit no explanation. Nice selling pic though.
 
#46
I am not saying if those numbers and picture above is faulty. But I am a science teacher, if I were to grade these x-y table and pic, I would say the picture did not communicate what those numbers means, no unit no explanation. Nice selling pic though.
I think the idea is that there is a more consistent response of a larger portion of the string bed, but I agree that it's unclear and very confusing.
 
#48
I get the feeling that ERT3000 give a macro/average or simplified view of the stringbed. A simplifed view, i.e. provide one number for the whole stringbed, will not give you what is going on from one string to another.
 
#49
I get the feeling that ERT3000 give a macro/average or simplified view of the stringbed. A simplifed view, i.e. provide one number for the whole stringbed, will not give you what is going on from one string to another.
Not sure about that. ERT3000 gives different readings in different locations
 
#50
I am going to say this again. Does anyone measure the main and cross strings with Stringmeter after stringing with this method?

Data, we need more data.
I think this is the closest we have come (about mains/crosses tension, that is):

The mains string up 30-35% tighter than the crosses stringing mains and crosses at the same tension. I use 57/54-59/56 in a 16x19 with Gut/poly. For no reason other than it plays better for my game. Any more on the differential than 2-3lbs and I have a hard time hitting my spots on the serve. Creates more spin but at the cost of loss of control.
 
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