Custom Drilling: 10x19 Spin Pattern (Part 2)

Following the poor tension holding of the poly cross (link), I decided to re-string with full synthetic gut to test how this would perform.

A thicker gauge for the mains would be paired with a thinner one for the crosses.

Playtest:
- With full synthetic gut and without looking at the racket, I could not believe there were only 10 main strings!
- Comfort went further up a notch over the previous strings and control became as good as I could remember for this racket before the conversion.
- The amount of spin did not drop at all. It maintained as vigorous as with the poly cross. 
- The loud crackling sound of the mains moving during ball impact remained, followed by the ball kicking furiously towards my partner's face level.
- I felt much more relaxed and confident with this strings and thus swung smoother and harder than with the earlier poly cross. Perhaps this was why spin levels maintained, simply due to a harder hit?
- Visually, and with my partner's verbal confirmation, full syn gut generated a heavier ball. My partner recounted more racket twists (on his own racket) receiving off-centred hits than with my previous strings. In his words, he described my shots moving "fast and furious".
- On my side, I would attribute this to the extra power from the very open stringbed, rather than me exerting greater effort. I did not do anything differently.
- Throughout the 2 hours, I did not adjust the main strings at all. There was full snapback.
- Both serves and flat shots were equally good and accurate. No mis-directions. 

- A group who booked the courts after my session noticed my racket and asked if they could try it. I relented after seeing their Pro Staff RF97 Autograph and the Pro Staff 95s in exchange. They were similarly impressed!
- Again, towards the 3 hours mark, a main string snapped. The difference this time was it played well till it broke.
- Another significant difference was the hoop width compressed 1.0 cm immediately after just one main string snapped. This showed how much extra stress the lesser number of mains were withstanding compared to the crosses. Pics below.

Hoop width after one main snapped.

Close-up to eliminate parallax error. Width was 25.0 cm.

Hoop width after strings cut was 26.0 cm. Difference of 1.0 cm.

See the difference below? I was lucky the hoop survived!

Custom Drilling: 10x19 Spin Pattern

The open pattern spin craze has been around for a while now. So far, all of these open string patterns have been focused on reducing the number of cross strings.

But what if I skip some mains instead? How would that play? Would control be intact? Would spin increase more than reducing crosses?

I could not find any rackets with less mains than crosses. Add to that, being recently overdosed on boring and comforming modifications and stringjobs, I needed to break the mold again.

Below was the last pic in its 16x19 stock form before I started...

New holes were drilled to create the string pattern I desired.

Lots of paint chips but structure appeared intact and sound.

The original throat grommets were cut apart to allow me to choose which string hole to use.

After the throat area was completed, the top holes were drilled.

Then strung with very thick 15g synthetic gut to preserve control and durability! Unsure if the extra holes could hold up, I have never felt so much fear pulling tension before.

Fortunately, the mains completed without a hitch! Then the poly crosses. Hey! It's got ONLY ten main strings! Weaving was a breeze!

Conversion to 10x19 done. Hoop length and width measurements were perfectly in line with the original 16x19 pattern. Zero distortion achieved!

"Powerpads" were used at the throat to offer a bit more support for the third mains and to ensure the string stays away from the drilled inside edge.

At the newly drilled hole on top (2nd mains), tubing was used as I did not want to mess with the original grommets. 

String spacing for the mains was planned to incorporate some "proportional stringing" in the drill pattern. 

Put simply, the sweetspot area was designed to have a slightly denser string pattern than the outer mains. This adds control within the centre 6 mains while softening off-centre contacts around the peripheral.

Also, this ensures compliance with the ITF tennis rules regarding the stringbed (link), specifically, part "b", where:

"The stringing pattern must be generally uniform and, in particular, not less dense in the centre than in any other area."


Playtest:
- Sweetspot was really huge and forgiving, yet control remained very good. 
- The typical high rebound angle of open string patterns was not felt here. Unlike my earlier attempts at skipping crosses (link) where the rebound angle became high and sometimes unpredictable. 
- Volleys were extremely easy - in power, comfort and directional control. The large sweetspot helped too.
- Power was very good, and it came with more than enough control to direct it effectively and offensively.
- For serves, the spin was wicked! Compared to its former self, the extra power now meant the focus was on where to place it and how much to spin it. Less effort better result!
- Mains snapback was impressive. I could literally hear the strings crackling back and forth during ball impacts. When I pulled the mains aside and let go, it snapped back straightaway.
- Groundstrokes on both wings were good. No mis-directions other than my own mis-hits. Very impressive spin all around.
- Slices entered into "obscenity eliciting" territory for my playing partner. Hit one slice, get one !@#$%^)*.
- After an hour, a slight string buzz appeared. The mains still snapped back instantaneously when pulled and released. Not so with the poly crosses. It seemed the crosses had been the one doing the control work and became "fatigued".
- The above was based on about an hour with this setup. So far, it seemed that skipping mains generated better spin than skipping crosses. Very impressed and excited to test it out more against different players.

17Feb2015 update:
- From the start of the 2nd session of use, tension loss from the poly was very significant.
- While spin was still very good, control dipped badly. I had to focus very intently to be sure my shots landed close to where I aimed.
- I continued playing just to experience how long the mains would last and how it felt when the poly cross tension dropped further.
- At around the 3 hour mark (total use), a sweetspot hit snapped a main string.
- Overall, I was impressed by the spin and comfort this setup gave. Durability in terms of tension holding and string life was not up to my expectations, so I would be re-testing it with another string setup.

Another Classic: Yonex RexPlay 2

Just strung up another vintage racket for M, a Yonex addict.

M cut out the old strings before I could examine the stringing pattern and shared holes. Took us a while to agree that this stick had a 16x19 pattern instead of 16x20.

String Pattern: 16x19
Mains Skip: 8 Top, 8 Bottom
Shared Holes: 9 Top, 7 Bottom, 9 Bottom
Strung Weight: 352 grams (with new replacement grip)
Strung Balance: 32.0 cm (with new replacement grip)
Estimated Swingweight (strung): 330 kg/cm²

There was lots of creaking and squeaking while tensioning. It could be from the aged grommets and soft flexy hoop. As with all vintage frames, I do not recommend restringing this too often.

My Gut/Poly Experience

Natural gut always attract a lot of interest and attention. It is a pricey string, but it also plays second to none. 

As soon as I posted my second "pilgrimage" (link), I received a barrage of questions on how the setup plays, how long it lasts, is tension holding really that amazing, how much it costs, etc.

To save myself from becoming a broken record, I compiled some observations in this post.

Stringing
- Before opening the pack of natural gut, every grommet hole must be carefully inspected for sharp edges. Any found must be gently and smoothly sanded down. Then checked again.
- New grommets or new unstrung rackets should not have natural gut as their first stringjobs.
- Gut kinks easily. Previously, I accidentally dropped the gut after snipping off the cable tie and the entire 40 ft tangled up in a huge mess! (link). A light prestretch is a must. Not optional.
- After the prestretch, I always inspect the gut for any kinks or bad patches before stringing. If found, photos were taken and sent to the owners to decide if they want to proceed at their risk.
- To prevent friction burns, either with the grommets or the crosses, waxing is a must. I do it twice - before and after stringing.
- All clamps, including the string gripper, should be cleaned and adjusted before stringing. Too tight and the gut flattens or snaps. Too loose and it slips. 

Playing
- Some claimed gut needed a break-in period. Mine played well from the first hit.
- Gut/poly was very lively, crisp and pocketed the ball very well. The string rebound was fast and powerful. The long dwell time allowed me to execute a lot of strokes I usually could not. Even late hits or last minute saves sometimes became offensive shots!
- Spin was very easy and serves were effortless. Mid-game, when I swapped back to my full syn gut for a test, I had to swing so much harder for my serves. And I lost a lot of control and double-faulted!
- Visually, my partners and I noticed my ball speed was much slower with syn gut. They could chase and return what would have been winning passing shots with natural gut.
- Comfort was supreme! The ball must have enjoyed the hits! It probably felt more like landing on a plush pillow than being bashed by a tight stringbed.
- Even with the small 85 square inch frame, I felt gut/poly opened up the sweetspot larger than on a 100 square inch frame with other strings. It inspired confidence to just let go and rip the ball back. And most times, it turned out perfectly, just like on TV! So much so, that at times, I believed I could execute some of those shots-of-the-day by the touring pros. 
- Instantly, just by using gut/poly, it gave me about a 30% improvement in my overall game.

Tension Holding
- Tension stability was impressive. Nothing comes close.
- Stringbed frequency measurements below:

Total Usage (hours)	Frequency (Hz)
Strung	659.0
1.5	648.0
3.0	643.8
4.0	640.9
6.0	639.3
8.0	637.0

- As a comparison, most other strings usually drop about 30 to 40 Hz overnight after stringing without play. This setup lost only 22 Hz after 8 hours of play.
- Playing conditions (in Singapore) for the 8 hours was in the low 30s degrees Celcius. New pressurized balls were used, sometimes new Wilson trainers.
- Being excited with the setup, I stood slightly further back from the baseline than usual and swung much more freely than with my usual syn gut. In other words, I bashed the ball much harder than usual.

Poly String Death
- Since I restring myself, and none of my strings were used beyond 10 hours, I am very sensitive to flat strings. 
- Somewhere around the 4th or 5th hour of use, I started struggling with this stringbed. Initially, I thought I was not performing well that session. Felt sluggish, lacked power and sprayed some shots wide. I stepped up and swung harder.
- Then, the tennis balls felt a little flat. So I changed to new balls. Immediately, control dipped. Shots flew long. 
- The rebound timing of the stringbed was off. When fresh, the ball pocketed deep, then came off the strings enthusiastically, powerfully. Now it felt tired. It pocketed, but returned much slower and weaker. This longer dwell time meant a later part of my follow-through was now determining the ball trajectory.
- By the 5th session of use, which was going into its 7th and 8th hour, the sweetspot almost completely disappeared. Most of my impacts felt more like framed-shots with some light string buzzing. 
- My serve lost so much pace and control. Volleys were so weak the ball kept dropping into my side of the net.
- The racket became very difficult to use and dragged me down. Shots that previously could be pulled off all fell flat.
- For the first time, the kevlar/graphite composite PS6.0 felt stiff with jarring vibrations! Both my wrist and elbow felt very uncomfortable too.

- As a simple test of resiliency, I pulled several gut mains apart and released. All snapped back very quickly. Pulling the poly crosses aside was so much easier. Less strength was needed and less resistance encountered. Not a single cross string snapped back when released. (See crosses 3 to 11 above, all pulled aside)
- Clearly, the gut was still behaving very well, and was supporting the bulk of the ball impact. However, the huge tension loss in the poly created too much "slack" for it to be of any further use.

Replacing Only the Crosses
- The beauty of a gut/poly hybrid is, you can restring ONLY the dead poly!!! (If your stringer would not do it, find another who would!)
- Beware! Hybriding poly with gut WILL NOT insure you against wrist pain nor tennis elbow. Mine hurt after merely 6 hours of use. The poly "died". Use poly safely. Always replace them after 8 to 10 hours, or less.

- While removing the cut poly strings, a sharp edge caught on the gut and snapped the 7th main. Fortunately, the tension loss was contained within the top 2 and bottom 2 crosses due to the way I had strung earlier (link).
- I clamped the 4th main on both sides, re-worked and re-tensioned only the 5th and 6th main strings. Thus converted the gut to fill only the centre 12 mains. The centre 8 mains were completely untouched from its initial stringjob.

- I smeared some coconut oil on the gut strings to lubricate it. Then filled all the rest with synthetic gut and saved a snapped gut string job!

Playtest
- The stringbed came to life again! 
- All the earlier felt components - power, control and comfort came back in full force! Only spin was slightly less than before.
- At my first session after this re-work, my partner, "F", commented via a sms message after our game:

"Actually today your shots were pretty accurate, percentage higher than all other times. Strings or skill?!"

- It had to be the natural gut! How could I improve so fast?