Both previous attempts with 15g syn gut/poly (link) and 15g syn gut/17g syn gut (link) suffered string breakages after a few hours.
All other aspects like comfort, spin, power and control performed much better than expected. So I thought of installing some bullet-proof kevlar in the mains to see if I could beef up durability a little.
The kevlar/syn gut combo played the most spinny among them, with slightly better control and a bit less power.
Unfortunately, this setup also lasted only 2+ hours. (Note the instant frame distortion after the mains snapped)
With such a ridiculous open pattern, something has to give. And in this case, it was durability.
Given how enjoyable the 2+ hours was, and how easy it was to string and weave this racket, I think it was worth the trouble.
The pre-stretched poly played much better than expected. (link) In total, it lasted about 12 hours before a main snapped. It was truly good till the last hit. Not something I would expect from full poly.
Since I had about half-set of that poly leftover, I used it in the crosses with syn gut mains. Both pre-stretched, of course.
Tension holding and the initial tension drop was similar to the fullbed of poly. After the overnight and initial hits drop, it stabilized.
With syn gut mains, the feel and power was much nicer. I felt I could "load" the strings better for more of my usual shots without trying to crank it up.
Although softer than full poly, control remained more than enough. There was no "mis-behaved" shots that I could attribute directly to the strings. The fault was mine.
The "fast strings" feel was more apparent in this setup. There was more power, more pace. Even serves attempted just after 20 minutes of light use felt good. The stringbed was powerful and responsive enough for me.
With a different partner testing this out with me, I could not tell for sure if spin was better than the pre-stretched full poly. However, it was enough for me, when my partner called the ball in several times, just when I thought it was going long. From that, I deduced the topspin had to be more than my usual, since I interpreted it should have gone long.
My greatest satisfaction from this setup comes from the impeccable stringbed consistency. Over two hours of play, the difference in feel between the first few hits and the last shots was so minute compared to strings without pre-stretch. All along, this was something I could only enjoy with natural gut. Now no longer.
Tension loss, measured through frequency in hertz:
Overnight after strung --> dropped 7.8 hz
After 1 hour play --> dropped 3.1 hz
After 2 hours play --> dropped 0.2 hz
How's that for tension maintenance?
Conventional advice is to tension poly carefully with the slowest pull setting in the machine. That preserves the limited amount of elasticity in the string. (link)
The elasticity of nylon/mutifilaments allow them to stretch about 10-12%, natural gut about 7% and most polys only around 3-4%.
What I could not reconcile with, is that these poly strings, with the worst tension maintenance, is always prescribed for the hardest hitters who break strings frequently. See the dichotomy?
While the string breaking may be taken care of, what about the tension holding? It still becomes unplayable. So, poly users are recommended to restring regularly.
But how is breaking nylon/multi after a few hours different from cutting out spent poly in the same amount of time?
After two months, a full reel of poly, and deriving only about 4 hours of play per racket, both my big hitter friend and myself got tired of this incessant need to restring.
Against conventional wisdom, and encouraged by positive feedbacks of pioneers online, we pre-stretched the poly string before stringing.
To add a layer of protection from the super-boardy elbow-busting string bed we were anticipating, we hybrid the perimeter with softer synthetic gut, also pre-stretched. And used my arm-friendlier Pro Kennex instead of his stiffer rackets.
Playtest:
- Simple bounce tests after stringing indicated the string bed was about as soft as a brick wall. No pocketing at all.
- The frequency was monitored immediately off the stringing machine and at different intervals.
- After an overnight rest unplayed, the first observation was impressive. String bed frequency dropped by only 9 Hz compared to the usual 40 Hz. This loss was similar to a freshly strung gut/poly hybrid left overnight. Unprecedented for any poly or syn gut.
- On court, the entire first hour played stiff and powerless but NOT boardy at all. The usual break-in after about 20 minutes of rally did not happen. It maintained almost exactly the same tight controlled feel as the initial hits, only softer.
- Spin was impressive. Very much better than without pre-stretch. Could be the tightness encouraging us to swing away freely. We had fun hitting some new extreme angles previously impossible, and watching the ball curled in.
- We switched to serve practice. Being the weaker hitter, I served first. It was disastrous. There was not enough power to drive the ball even on flat serves. Comparing the slow-motion video frames with my usual strings, I lost about 25-40% ball speed. Clearly reminded myself why I did not like could not use poly. (link)
- However, in the hands of my hard-hitting partner, it was like a dream come true. Alternating with his other freshly strung unprestretched stick, I could see there was absolutely no doubt nor hesitation with the pre-stretched strings. He just let it go full blast. From video reviews, serve percentage, serve speed, placements were all better.
- That took about an hour and we measured the frequency again. It dropped only another 11 Hz, compared to the usual about 30+ Hz.
- Somewhere after 90 minutes of use, I took over the racket for rallies again. By then, the pocketing and sweet spot opened up significantly. There was more proportionate power. Harder hits had deeper pocketing and softer hits less pocketing. Strangely, it reminded me very much of synthetic gut!
- For once, we could even volley decently, with good feel, using this poly string!
- In my partner's words, another distinct difference was that this poly became a "fast string", like natural gut, instead of its usual "slow and sloppy."
- At the two hour mark, it dropped only another 0.8 Hz.
- Immediately, this chap handed me both his rackets to be re-strung. I think we're onto something significant...
Through M's introduction, T asked if I could take a look and see if I could recommend something for his existing strings setup.
The first glance at his racket strings shocked me!
Not only was the kevlar and syn gut hybrid set in the wrong order - with kevlar in the crosses, there was also a double string knot tied at the bottom 6th main.
My first question was, if there has been any pain or discomfort in his wrist or elbow from playing with that setup. Luckily, the racket was very flexible. Else it would have been disastrous!
Since T hits flat, I advised him to cut this out and re-string it with plain old synthetic gut.
The weight printed on the racket throat stated 275 grams but did not specify if that was strung or unstrung. So a quick check on the scale was done. 302 grams strung and with dampener.
Then I measured the inside hoop length and width with the syn gut/kevlar setup. Length was 322mm and width 255mm.
Then I cut out the strings and checked the unstrung inside hoop dimensions. About 326mm by 256mm. So the syn gut/kevlar caused a distortion of 4mm and 1mm respectively.
The racket was then strung with a full bed of synthetic gut. Strung inside hoop was 326mm and 254mm. Distortion from unstrung was 0mm and 2mm respectively.
T also mentioned the butt cap was shaky. So I removed the staples and checked if the pallet or foam was intact.
A common mistake is to use super glue to hold the butt cap stable. It will work for a while, but then the entire foam would disintegrate as super glue melts foam.
So I used thick double-sided adhesive tape to tighten the fit, then sprayed a squirt of rubbing alcohol to activate the tape before pushing the butt cap in firmly. Then stapled it down. That took care of the wobble.
T's grip was a little too big for him. To reduce it by half a size (1/16"), I stretched out the replacement grip a little before wrapping it back. That brought the grip size down from 4 3/8" to 4 5/16".
Hopefully the grip stays and he has a more enjoyable game with this.
This post was meant to document the changes made for T, and perhaps a reminder to fellow tennis players that kevlar should never be used in the crosses. Unless one wants his wrist or elbow destroyed.
Since it was so near April Fools' day when I posted the natural gut/fishing line combo (link), some asked if I was pulling a prank again (link).
Not this time!
The slick fishing line really paired very well with the natural gut mains. So well, that two playing partners asked if I could switch to another racket instead. They just didn't like to be on the receiving end of those two strings combo.
It was so addictive that I just strung up a kevlar/fishing line to see how much more I could accentuate the already spinny kevlar!
