Hybrid Stringing = Dangerous Tension Imbalance?

[kinsella]

Even when a poly main is originally strung at the same tension as a synthetic gut, multi or natural gut cross string, the poly mains are going to lose tension faster than the crosses, so that a tension imbalance is likely to distort the shape of the racquet head. Playing the stick in this condition has to be worse than leaving a frame sitting for weeks with a broken main string -- right?

The same dynamic is in play with natural gut mains, poly crosses, just going in the other direction.

This issue is an even greater concern with the crosses are strung tighter than the mains.

Can this imbalance and resulting head distortion cause racquet damage?

[bad_call]

Originally Posted by kinsella

Even when a poly main is originally strung at the same tension as a synthetic gut, multi or natural gut cross string, the poly mains are going to lose tension faster than the crosses, so that a tension imbalance is likely to distort the shape of the racquet head. Playing the stick in this condition has to be worse than leaving a frame sitting for weeks with a broken main string -- right?

The same dynamic is in play with natural gut mains, poly crosses, just going in the other direction.

This issue is an even greater concern with the crosses are strung tighter than the mains.

Can this imbalance and resulting head distortion cause racquet damage?

no problems here stringing poly mains and syn gut crosses (crosses 2-4 higher tension).

[-Bobo-]

Depends on the racquet in question, the difference in tension and the tension itself i.e. stringing 62/66 vs 42/46. I think the old head racquets were particularly susceptible but something like the wilson tour 90 etc you would be hard pressed to warp.

[TimothyO]

When I first tried hybriding I noticed something like you're talking about. It didn't warp the tennis racquet so it wasn't extreme. But I did notice an odd and unpleasant sound and a little loss of control. This occurred only with extreme differences in string characteristics.

Then I started paying attention to the relative tension loss stats and trying to account for them in the reference tension (to some degree...there are limits). I also have been trying to find strings that have similar tension loss. Currently I'm using VS 16 Mains @ 50# (-8.31 ) and Xcel 17 Crosses at 52# (-10.72) and have noticed the SB is very consistent and playable over an extended period of time. It's also very comfy!

Once I did push the envelope on relative reference tensions and the result was terrible (I think it was ~5# difference). No control, God-awful sound, just like having similar reference tensions but significantly different tension loss.

[Speed Kat]

Kinsella you are totally correct with regards to the phenomenon you have identified. However, is it dangerous or would it really matter that much is open to debate. If your tensions are well within the recommended ranges and not extreme tensions - (like some ppl string their racquets at 70# etc.) - but rather you are dealing with a gut 53 and alu poly 50 for example despite tension loss at differing rates you really have nothing to worry about... I doubt it will affect the quality of play or the integrety of the racquet enough that there would be discernable or noticable effects. Chances are something else will "get" the racquet in a worse way like it being on the car seat and a 225lb passenger sits on it, or getting angry after losing an important point and giving it a nice hit on the floor or fence or somethign like that.. but dont worry about warping issues.. most new raquets these days anyway are $200 worth of volcano, graphite, tungsten, moon dust, adamantium, kryptonite, biomimicite, d30, innegraphite, or whatever else so trust me it can probably take it!

[A Defenseless Creature]

I can not see any danger whatsoever to the frame. Each string, regardless of construction, will lose some degree of tension over time. Let's assume string A loses 19% while string B loses just 10%. Let's assume the racquet was strung at 58 lbs. String A loses approx 11 lbs while String B loses just 6 lbs. That is a difference that is nowhere near enough to distort the frame. In fact the majority of stringers experience slippage and inconsistency (whether they will admit it or not) during installation and the disparity between strings can be much more than 6 pounds with a non-hybrid setup. (Take a Stringmeter and measure each string on any of your racquets to see what I mean). The phenomena described is not alarm worthy. Nothing to worry about, IMO.

[Lambsscroll]

Don't string manufactures sell hybrids? Do they warn you in anyway about hybrids in general?

[SirGounder]

Judging by how many people use a hybrid setup with varying tensions, I would say it's not enough of an issue to really worry about. Maybe on an older racquet or like others said if you are going for really crazy tensions. Maybe it might be an issue if your racquet took a good hard smack on the ground as punishment for hitting that last shot into the net. I've been hydriding a lot lately and have not noticed any warping. I measured the head before stringing and right before I cut the strings out.

[kinsella]

My personal favorite response is Lambsscroll's. I would add that many of the hybrid string sets are sold by racquet companies (e.g. Wilson, Babolat)

[Lambsscroll]

Originally Posted by TimothyO

When I first tried hybriding I noticed something like you're talking about. It didn't warp the tennis racquet so it wasn't extreme. But I did notice an odd and unpleasant sound and a little loss of control. This occurred only with extreme differences in string characteristics.

Then I started paying attention to the relative tension loss stats and trying to account for them in the reference tension (to some degree...there are limits). I also have been trying to find strings that have similar tension loss. Currently I'm using VS 16 Mains @ 50# (-8.31 ) and Xcel 17 Crosses at 52# (-10.72) and have noticed the SB is very consistent and playable over an extended period of time. It's also very comfy!

Once I did push the envelope on relative reference tensions and the result was terrible (I think it was ~5# difference). No control, God-awful sound, just like having similar reference tensions but significantly different tension loss.

Which Xcel are you using? Power or Premium?

[Steve Huff]

I use natural gut in the mains and an 18g poly in the crosses. I string the poly 4-5 pounds lower than the mains. Plus, I'm sure the poly loses tension a lot faster than the gut, so the differential is probably huge by the time they break. I've never had a problem, and I've been stringing hybrids since around 1985 or so.

[corners]

I've always been a little concerned about this, especially as I play with frames no longer in production.

I was planning on getting a Stringmeter, thinking it could read the tension of the main and cross strings separately. It can't.

There are definitely two schools of thought on this: 1) initial tension loss for a poly is greater than gut or nylon, but after that the tension of a poly "locks in". So the difference in tension ultimately is not so great. So don't worry about it.

2) The lab evidence shows that the tension of a poly does not "lock in" when subject to repeated impacts. Poly continues to lose tension upon each impact, whereas natural gut loses about 10 pounds and then stays there. So if we consider this evidence as solid, and relevant to on-court reality, we have to be concerned about differential tension loss and frame distortion.

TW University's data shows, for example, that if we string gut at 60 pounds and hit it with a hammer to simulate 20 120 mph serves, it will lose 10 pounds of tension and end at 50 pounds. The same treatment will take an average copoly string from 60 pounds to 30 pounds of tension.

The only way I can think of to check this is to measure the distance from butt to tip 1) before stringing, 2) immediately after stringing and 3) just before cutting out to restring (or just before breakage).

If measurement 3 is less than measurements 1 and/or 2, then you know that your poly crosses have lost enough tension to widen the hoop and shorten the racquet.

I'll take some measurements on my next several hybrid jobs and report back to this thread. If everyone did this we'd have some data to answer the OP definitively.