Gut / poly hybrid - same tension or differential?

jstwtt

New User
Hi all,

What tension differential do you all recommend in a gut / poly hybrid setup?
Most ATP players seem to string 2-4 lbs higher on the gut mains than the poly crosses, but they also switch to fresh strings before the poly loses much tension.

I've been using a 2 lbs differential (mains Babolat VS Touch 17 @ 53 lbs x crosses Luxilon 4G Soft 1.25 @ 51 lbs in a 18x20 pattern) and love it! but looking to further improve that setup.
What puzzles me is that once the poly loses tension the differential gets much bigger than the original 2 lbs.

Using RacquetTune, on fresh strings I consistently get the average between 53 lbs and 51 lbs: 52 lbs, which looks just about right.
The next day I typically get 50 lbs, so assuming the gut is only 1 lb down to 52 lbs (from prior experience with full gut) that places the poly around 48 lbs: a 4 lb differential.
After a few days things eventually stabilize at 48 lbs and I'm pretty sure the gut is still at 52 lbs, placing the poly at 44 lbs: now a 8 lb differential, isn't that too much then ?!

So I'm wondering if we (normal players, not getting fresh strings as often as the pros) would benefit from stringing the poly at the same tension as the gut to help minimize the differential once it loses tension...

Thoughts?
 

SinneGOAT

Hall of Fame
In an 18/20 I did 53 for gut mains and 48 for 4g cross. In racquets that are very low powered I go 4-5 lower on cross(also depends on what string is the cross) and then in higher powered racquets I string a differential of 2.
 

jstwtt

New User
In an 18/20 I did 53 for gut mains and 48 for 4g cross. In racquets that are very low powered I go 4-5 lower on cross(also depends on what string is the cross) and then in higher powered racquets I string a differential of 2.
Thanks! So when you start with a 5lbs differential how long does this play well before you have to cut and restring? With the poly losing tension you must be at a 11 or 12 lbs differential after a few days... Does that still play as well as 5 lbs?
 

SinneGOAT

Hall of Fame
Thanks! So when you start with a 5lbs differential how long does this play well before you have to cut and restring? With the poly losing tension you must be at a 11 or 12 lbs differential after a few days... Does that still play as well as 5 lbs?
You can do a difference of 2-4, but with 4g it never lost tension. I played with it till the gut broke, which was a month and the tension held. For reference, I was playing about 15-20 hours a week, not including tournaments.
 

jstwtt

New User
I prefer gut/poly at the same tension, even in 18x20. Gives a more predictable hit.
That's my thinking too, so I'm trying to understand why most people use a differential, and are ok with that differential going from 2-5lbs into the 8-11 lbs after a while... Is there any benefit at all?

Also how often do you restring? If like we're saying here a 0 lb differential is more predictable, after a while you're probably still getting to a 6 lb... Is that becoming less predictable then? or do you just cut and restring before you get there?

Thanks!!
 

jstwtt

New User
You can do a difference of 2-4, but with 4g it never lost tension. I played with it till the gut broke, which was a month and the tension held. For reference, I was playing about 15-20 hours a week, not including tournaments.
Thanks! Maybe I should try 4g instead of 4g soft then... 4g soft is losing tension over time for me, like I tried to describe in my original post.. If 4g keeps it's tension almost as well as the gut, then a 2lb-4lb differential makes a lot of sense indeed as 4g is so much stiffer than the gut, and if it stays constant you get the best of both worlds!!

I still have another week or so with my current string job I think, going to consider normal 4g instead of 4g soft next time... Thank you for your insight!!
 

Soho78

New User
That's my thinking too, so I'm trying to understand why most people use a differential, and are ok with that differential going from 2-5lbs into the 8-11 lbs after a while... Is there any benefit at all?

Also how often do you restring? If like we're saying here a 0 lb differential is more predictable, after a while you're probably still getting to a 6 lb... Is that becoming less predictable then? or do you just cut and restring before you get there?

Thanks!!
I read somewhere that in general the crosses should be a 4lbs less than the mains. Reason being the crosses are shorter in length and hold tension better/longer than the mains. Not 100% sure on this, but I believe Yonex recommends this approach.
 

aaron_h27

Professional
That's my thinking too, so I'm trying to understand why most people use a differential, and are ok with that differential going from 2-5lbs into the 8-11 lbs after a while... Is there any benefit at all?

Also how often do you restring? If like we're saying here a 0 lb differential is more predictable, after a while you're probably still getting to a 6 lb... Is that becoming less predictable then? or do you just cut and restring before you get there?

Thanks!!
I have three rackets, always re-string one before a match regardless of tension loss. I practice with loose strings and play with tighter ones for extra control during matches.

It doesn't matter if you use a differential or not, the cross string tension will determine how control oriented the string bed is.

For example 66/60 would play looser than 63/63

The problem with 66/60 is that 66 on gut mains lowers the durability quite a bit. The higher you go on gut the lower the durability.

The best thing in my opinion would be to go as high as you can with the gut (to retain softness) without sacrificing durability and lowest you can on the poly to retain control.

Also keep in mind that when the crosses lose tension (or you string them 5-8 lbs looser than mains) there is a lot of hoop squashing, which lowers the swingweight, something to keep in mind.
 

socallefty

Hall of Fame
I string poly crosses 3 or 4 lbs less than the gut mains. Purely based on empirical experimenting on what feels best for my game. I started with stringing at a 2 lb differential and progressively went lower as the poly always feels better to me when it is at a much lower tension. I now string VS/HyperG Soft at 48/44 or 47/44 lbs on a Pure Strike Tour.
 

Dartagnan64

G.O.A.T.
Depends on the crosses. I'll usually put gut mains in at 58 lbs on16x19 frames and 54 lbs on 18x20 frames. The crosses will vary depending on their stiffness with the lowest tensions for stiffer crosses like 4G and the higher tensions for soft poly's like Cream.

So a typical Gut/Cream, 16x19 frame would be 58/54 for me. Gut/4G would be 58/50 in the same string bed.
 

SinneGOAT

Hall of Fame
Depends on the crosses. I'll usually put gut mains in at 58 lbs on16x19 frames and 54 lbs on 18x20 frames. The crosses will vary depending on their stiffness with the lowest tensions for stiffer crosses like 4G and the higher tensions for soft poly's like Cream.

So a typical Gut/Cream, 16x19 frame would be 58/54 for me. Gut/4G would be 58/50 in the same string bed.
So for something like gut/4g in a 16/19 would you say 56/51 be good?
 

am1899

Hall of Fame
I read somewhere that in general the crosses should be a 4lbs less than the mains. Reason being the crosses are shorter in length and hold tension better/longer than the mains. Not 100% sure on this, but I believe Yonex recommends this approach.
Yonex used to recommend crosses strung 4lbs looser because of their isometric head shape. They no longer require that to maintain warranty.

While crosses are generally shorter than mains, crosses are also woven against the mains. So assuming the same tension setting on the machine throughout the string job...because of the friction to be overcome caused by crosses being woven, already, your crosses aren’t going to be pulled with as much force as the mains were earlier in the job. Reducing the tension setting on the machine for the crosses is going to exacerbate that delta further (which, depending upon what you’re trying to do, may or may not be desirable).

I have doubts that cross strings will fair much better (if at all) than mains in terms of holding tension. Unless in the case of a hybrid, where the type of cross string used is characteristically better in this aspect than the string chosen for the mains.
 

am1899

Hall of Fame
Also keep in mind that when the crosses lose tension (or you string them 5-8 lbs looser than mains) there is a lot of hoop squashing, which lowers the swingweight, something to keep in mind.
Not only that, potentially you are changing the shape of the racquet. A lower cross tension than the mains will generally result in, as you say, a squashed hoop, and an overall shorter racquet.

I totally understand why a lot of folks like the differentials - especially with a gut/poly hybrid. But there are some pros and cons to consider.
 

Dartagnan64

G.O.A.T.
So for something like gut/4g in a 16/19 would you say 56/51 be good?
Dependent on a few more things than just string bed density. Inherent frame power, how much RHS you get and how much spin you play with.

i'd not use that tension in a PD but would use it in a Phantom 107G, for instance.
 

Dartagnan64

G.O.A.T.
Not only that, potentially you are changing the shape of the racquet. A lower cross tension than the mains will generally result in, as you say, a squashed hoop, and an overall shorter racquet.
I've not noticed in any length differential in rackets with up to 8 lbs tension difference.
 

am1899

Hall of Fame
I've not noticed in any length differential in rackets with up to 8 lbs tension difference.
Well, how carefully are you measuring? ;)

If I portrayed that a differential will absolutely cause a shorter racquet...my apologies, I didn’t mean to say that. There are many other factors at play - how the racquet was mounted to the machine, the skill (or not) of the person who strung the racquet, the strings chosen, the string pattern, the racquet itself (some are more or less prone to deformation), etc.

What I can say rather definitively, is that a tension differential where the crosses are strung at a lesser tension than the mains increases the risk of squashing the hoop and therefore (slightly) decreases the length of the racquet. Something to watch out for, that’s all.:)
 

SinneGOAT

Hall of Fame
Dependent on a few more things than just string bed density. Inherent frame power, how much RHS you get and how much spin you play with.

i'd not use that tension in a PD but would use it in a Phantom 107G, for instance.
I use a blade 16/19. I don’t hit with a ton of spin but I do hit with a medium-high rhs. I prefer volleying and moving in, and I’m not grinding away at the baseline. Would that be a good tension for my style?
 

Dartagnan64

G.O.A.T.
Well, how carefully are you measuring? ;)
Careful enough that it would have to be a millimeter difference for me not to see it. Which is probably within the variance I've seen in general with rackets.

I use a blade 16/19. I don’t hit with a ton of spin but I do hit with a medium-high rhs. I prefer volleying and moving in, and I’m not grinding away at the baseline. Would that be a good tension for my style?
Yes 56/51 would be a good place to start with Blade 98 V7 16x19.
 

tonylg

Legend
You can do a difference of 2-4, but with 4g it never lost tension. I played with it till the gut broke, which was a month and the tension held. For reference, I was playing about 15-20 hours a week, not including tournaments.
I would question any string not losing tension over 60-80 hours, but can't get past the fact you play with 4G for that long.

Ouch!
 

SinneGOAT

Hall of Fame
I would question any string not losing tension over 60-80 hours, but can't get past the fact you play with 4G for that long.

Ouch!
Honestly the gut and it being an 18/20 really helped, the gut at like 53-55 kept it comfortable, and the blade was noodle soft, win win :)
 

stapletonj

Hall of Fame
I have been experimenting with a gut poly hybrid combo for several months now. I have found that at least a 10% increase in gut tension in the mains is a good idea. string the poly crosses like you normally do. this should result in a 4-6 lb. differential,

my gut has been hanging in in there, but there is a slight tension loss over time. feel and etc is still there, but just a little harder to control.
I play a yonex vcore 100 and hit kind flattish because I'm old.
 

SinneGOAT

Hall of Fame
Depending on the racquet and how much you measure the string, you can actually get two string jobs for the price of one. Had 1 pack of gut and poly, correctly measured and had enough gut and poly for two racquets, both gut main/poly cross. If you had an 18/20 this probably won’t work.
 

jstwtt

New User
You can do a difference of 2-4, but with 4g it never lost tension. I played with it till the gut broke, which was a month and the tension held. For reference, I was playing about 15-20 hours a week, not including tournaments.
Thanks! Maybe I should try 4g instead of 4g soft then... 4g soft is losing tension over time for me, like I tried to describe in my original post.. If 4g keeps it's tension almost as well as the gut, then a 2lb-4lb differential makes a lot of sense indeed as 4g is so much stiffer than the gut, and if it stays constant you get the best of both worlds!!

I still have another week or so with my current string job I think, going to consider normal 4g instead of 4g soft next time... Thank you for your insight!!
Now that I think about it more, 4G soft also holds tension well. After an initial drop from 51lbs to 44lbs it stays there, with Racquet Tune giving me a stable 48lbs overall for several weeks... I'm not seeing any noticeable change in the feel of the string bed either, which I guess is primarily coming from the gut being in the mains and dominating the feel anyway.

I'm now debating between trying out gut + 4G as an alternative with slightly better tension maintenance vs continuing with the gut + 4G soft combo which has worked well for me in the last two years... There are just too many choices :)
 
Also keep in mind that when the crosses lose tension (or you string them 5-8 lbs looser than mains) there is a lot of hoop squashing, which lowers the swingweight, something to keep in mind.
Not only that, potentially you are changing the shape of the racquet. A lower cross tension than the mains will generally result in, as you say, a squashed hoop, and an overall shorter racquet.
This is starting to bug me. I really like gut/poly, but as the poly loses tension, I get hoop deformation so that my frame is up to 1/8" short. The tension differential increases along the way, which changes stringbed response. It stays playable for a while, but it bugs me...and with gut, I can't afford to put in a fresh set for every match. Currently using Yonex PT Fire as a cross. Might have to resort to re-stringing crosses (yikes), pre-stretched poly, or both. If anyone has experience with a good solution, I'm all ears.
 

aaron_h27

Professional
This is starting to bug me. I really like gut/poly, but as the poly loses tension, I get hoop deformation so that my frame is up to 1/8" short. The tension differential increases along the way, which changes stringbed response. It stays playable for a while, but it bugs me...and with gut, I can't afford to put in a fresh set for every match. Currently using Yonex PT Fire as a cross. Might have to resort to re-stringing crosses (yikes), pre-stretched poly, or both. If anyone has experience with a good solution, I'm all ears.
Try stringing your crosses 2-3 lbs tighter than the mains
 

am1899

Hall of Fame
This is starting to bug me. I really like gut/poly, but as the poly loses tension, I get hoop deformation so that my frame is up to 1/8" short. The tension differential increases along the way, which changes stringbed response. It stays playable for a while, but it bugs me...and with gut, I can't afford to put in a fresh set for every match. Currently using Yonex PT Fire as a cross. Might have to resort to re-stringing crosses (yikes), pre-stretched poly, or both. If anyone has experience with a good solution, I'm all ears.
You’re on the right track - pre-stretched poly is, IMHO, the best answer to that riddle - Kirschbaum, 4G, etc.

Restringing the crosses, although possible, I wouldn’t recommend. No matter what you do, you can’t recreate the initial string job with the subsequent one - because you’re only replacing half of the string bed.
 

AceyMan

Semi-Pro
in general the crosses should be a 4lbs less than the mains. Reason being the crosses are shorter in length and hold tension better/longer than the mains.
Sounds good on paper—wrong in implementation.

The drag of pulling the cross thru the mains exceeds the differential, and then some.

I would string the crosses 2 kg higher, at minimum.

Also, poly has a fraction of the elasticity of gut. Unless the poly is strung high enough, the gut mains will shorten the hoop.

In a gut mains / poly cross setup I would start with the mains 1 kg less than I use in a full bed, and string the poly crosses 2–3 kg more than that.

/Acey

[edit: that last paragraph is for a START (off the top of my head, to boot). I actually don't favor gut/poly hybrids for that reason: the elasticity diffential is out of limits. But if you are going to do it, I provide a place to begin.]
 
Last edited:

TimePlease

New User
Sounds good on paper—wrong in implementation.

The drag of pulling the cross thru the mains exceeds the differential, and then some.

I would string the crosses 2 kg higher, at minimum.

Also, poly has a fraction of the elasticity of gut. Unless the poly is strung high enough, the gut mains will shorten the hoop.

In a gut mains / poly cross setup I would start with the mains 1 kg less than I use in a full bed, and string the poly crosses 2–3 kg more than that.

/Acey

[edit: that last paragraph is for a START (off the top of my head, to boot). I actually don't favor gut/poly hybrids for that reason: the elasticity diffential is out of limits. But if you are going to do it, I provide a place to begin.]
Very interesting. How would you adjust this for gut mains with a soft and slick multi cross like AK Pro CX?
 

Dartagnan64

G.O.A.T.
Also, poly has a fraction of the elasticity of gut. Unless the poly is strung high enough, the gut mains will shorten the hoop.
Find your kitchen scale and press on it hard enough to register 4 lbs. Now press that hard on a tennis frame and see if it in any way deforms the hoop. 4 lb differential will not shorten any frame that is decently made.

I just tested length on my 4 27" Phantoms strung all differently (multi at 57 lbs, gut/poly at 54/48, multi at 54, origin/velocity at 52/48). All rackets are the same length.
 

AceyMan

Semi-Pro
4 lb differential will not shorten any frame that is decently made.
Surely you mean => 18 x 24 kg (a representative sum of the mains tension), with a greater elastic range, as well, because ... gut .

The poly crosses don't easily add enough dynamic force to counter 400+ kgf of force already applied to the hoop unless the individual tensions are adjusted in some way such as I described.

/Acey
 
Top