Kevlar / Natural Gut Hybrid

Some deem this wasteful. To them, it makes no sense to pair the deadest string with the liveliest (and most expensive) one.

The most famous user of this setup was Andre Agassi in the 1990s.

This has been on my to-do list for very long, so I strung one up to experience first hand what's so special about it...(secretly hoping that I could return serves like Agassi!)

Compared to kevlar/syn gut, natural gut added a lot more comfort, power and spin.

No break-in was needed. It was comfortable from the first hit. The most impressionable item was the extra amounts of dampening.

With syn gut crosses, kevlar felt a little harsh with a soft "pingy" vibration at impact even with a dampener. Natural gut crosses almost eliminated this ping. Sweetspot hits felt as comfortable as a full syn gut stringjob. But much more powerful.

What I did not expect from natural gut crosses was more spin. Compared to syn gut, natural gut was dry and "gummy". However, the kevlar glided smoothly, adding easy spin to serves and rallies without sacrificing power nor control. That is a huge plus.

The two major disadvantages were rapid fraying and that I could not use it in wet weather.

First pic below was after 3 sessions of about 2 hours each. Visible fraying commenced.

Pic below was after 7 sessions. Spin seemed to decrease gradually with each session but comfort and power was consistent.

Given the marginal improvement over syn gut crosses, I am unlikely to try this combination again. However, I am glad to have this item completed from my to-do checklist!




   

Kevlar Crosses!?!?

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.

Kelvar / Fishing Line

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!

1.10mm Kelvar + Syn Gut in Black Ace 98

After getting tired of the constant need to restring the "snappy" fishing line, I thought of using Kevlar to give myself a "stringing break".

I got hold of a pack of 1.10mm aramid for the mains and paired it up with syn gut.

Playtest:
- Kevlar usually has a break-in period of about an hour or two where it stretches very marginally. Thereafter, it stabilises until it breaks or gets restrung. 
- I was looking forward to this but was sorely disappointed. It lasted less than 30 minutes of play before snapping!
- Those 30 minutes played stiff as a board - powerless and spinless.
- I may need to re-test this.

Wilson PSC 6.1 + Kevlar/Syn Gut @ 45/30 lbs (14x16)

I'm firmly rooted in the ELT camp.

Eager to try more hybrids with ELT, I dug through my storeroom and cabinets to search for a racket that's due for re-stringing.

I saw my favourite PSC6.1 sitting alone, feeling abandoned in a corner. Then I recalled setting this up for my spin competition challenge in Nov 2012. (link)

The strings have easily 40+ hours of play but have not snapped. I can't remember why or how it was left in that corner. Maybe Pooh bear was fiddling with it?

Kevlar strings have almost zero stretch. So they do not lose tension nor playability. In fact, they feel "dead" straight from their packaging! Whether old or new, kevlar strings play exactly the same. The only thing to lookout for in kevlar strings, is to lose as little tension as possible during tie-off.

Another interesting aspect of kevlar, is that it plays very similar whether strung at 30 lbs or 60 lbs. This gave me the idea to cut out the dead syn gut crosses and string a fresh set at 30 lbs. 

I wonder how would the stringbed behave? With kevlar having zero flex and syn gut offering deep pocketing. What a contrast! This is going to be exciting!

For the frame's safety, I mounted the racket before snipping the crosses.

I can see some notching done by the poly crosses I used previously. No big deal here, if it breaks it breaks...

Here's a closer look at the notches on the kevlar.

Weaving the fresh syn gut skipping the top and bottom crosses to soften the stringbed. If you are a kevlar/syn gut user at any tension, try skipping all four outer strings. The harshness of kevlar would be greatly reduced but yet maintain superb control.

Here's the PSC6.1 twins together. The other's strung with natural gut / syn gut combo.

Playtest:
- This combination is a spin monster!!!
- Compared to fullbed syn gut, kevlar provided all the control I needed, and more. There is not a single stray shot due to ELT. All mis-directions were my fault!
- Strangely, the ELT syn gut provided a lot of pocketing. More so than I expected. I don't know how it happened with kevlar mains but it did. That made it SO comfortable I thought I was hitting with a soft poly.
- Even off-sweetspot contacts were not harsh at all. There were no jarring vibrations and the ball still managed to cross the net.
- Spin is what excels. This combo tops all other ELT strings I've tried. 1.10mm kevlar really bites. And when I needed more spin, a simple windshield-wiper whip generated easily twice as much spin as the next best string combo.
- Power levels are only very slightly lower than fullbed ELT syn gut.
- Among all my sticks, I think this setup will be the best for playing a control and accuracy game.
- Oh, and the sound of the ball impacting the stringbed is very different. Like a gunshot. I like it.
- Here's the ball fur pic. The pic clearly shows the darker shade of the cross strings as a result of the kevlar mains sliding and scraping across it.

19Jul2013 update:
- After not using this racket for almost 3 months, I took this out again for a game today.
- It did not disappoint, rather it excelled way beyond my expectations!
- Control was the best I have ever used in any tennis racket. Only with this setup could I bash away with a full swing for BOTH first and second serves. Most shots aimed down the line hit down the line about 2-3 feet from the baseline.
- Spin was very good. Kevlar bites well and adds even more directional accuracy which the stringbed already had in abundance.
- And it was very comfortable despite kevlar in a RA72 racket! I won 6-0 with this stick. Even my partner was totally astonished as how much control I had!

Strings:

Pro Supex Aramid 50 1.10mm mains @ 45lbs (untouched)

Pro Supex Synthetic Gut Titan 1.25mm cross @ 30 lbs

Spin Competition Day!!!

Having experienced the incredible spin from poly strings (link) and from kevlar (link), I thought maybe it would be interesting to compare the spin potential of different strings side-by-side rather than one at a time.

So, I re-strung two rackets this time:
- Pro Staff Classic 6.1 with Kevlar / Synthetic Gut hybrid
- Dunlop Aerogel 500 Tour with Full Poly

Before poly strings became popular, kevlar / synthetic gut hybrid has been the de facto king of spin. Few strings come close to its spin prowess. So I think this is going to be an exciting "competition".

Here's a pic of the PSC 6.1 completed. Afraid that the stringbed would play too stiff, I skipped the outer two main strings and outer two cross strings and converted the stringbed to a 14 by 16. Another reason is the slightly denser stringbed of the PSC 6.1 may give the Dunlop a slight advantage in spin generation potential. I hope this even out things a little.

Here's the Dunlop 500 Tour pics. This is done as a straightforward 2-piece job on the full 16 by 18.

Weaving the last cross. It's just so difficult to weave full poly!

Results:
PSC 6.1 + Kevlar / Syn Gut
- feels incredibly soft and powerful with absolutely no trampoline
- control was excellent and I was able to hit the corners accurately
- serves and volleys were good and very stable
- tension holding remains excellent after 30 min
- spin is excellent
- the racket sweetspot felt very large and easy to find

Dunlop 500 Tour + Shaped Poly / Soft Poly
- full poly wins in spin generation by a very slim margin
- stringbed felt soft, nice and powerful
- topspin increases automatically with harder hits and curls ball down
- a slight bouncy feel creeped in after about 15 min of hitting
- after 15 min, I could feel slight tension loss and string vibrations
- vibrations worsened after 30 min even with dampener
- started feeling harsh with buzzing vibrations which affected me

So overall, kevlar / synthetic gut hybrid gave me the better experience even though it lost in spin generation by a slim margin to full poly.

Strings:

Pro Staff Classic 6.1 (95 sq inch, done 14x16)

Pro Supex Aramid 50 1.10mm mains @ 45lbs

Pro Supex Synthetic Gut Titan 1.25mm cross @ 50lbs

Dunlop Aerogel 500 Tour (100 sq inch, done 16x18)

Pro Supex Super Nova Hex 1.23mm mains @ 47lbs

Pro Supex Big Ace Revo 1.25mm cross @ 45lbs

Wilson PSC 6.1 + Kevlar/Poly @ 45/50 lbs (14x10)

Having laid off tennis for so long means I can no longer find tiny sweet spots with ease. So the previous kevlar / poly hybrid has to go... (link)

Up till now, I still cannot fully understand poly strings. But I'm going to try pushing my luck! With my racket mounted, I carefully removed the poly strings again for re-use!

The kevlar @ 45 lbs is left untouched. I re-installed the poly at 50 lbs, skipping alternate cross strings to try to keep the stringbed soft for this combination of stiff strings. Another objective is to allow the kevlar room to slide for more topspin!

Weaving the crosses is a breeze! With flying clamps, I had to rely on the starting pin to keep each cross string tensioned. Definitely unusual, but that's what this blog is all about.

Even though it is a mere 5 lbs higher tension than previously strung, the poly string CONTINUES to stretch! The amount of slack during stringing and how far the dropweight falls is STILL more than the amount @ 45 lbs. (I had cleaned the clamps and jaws before this job so string slippage is very unlikely.)

Due to the skipped crosses, I had to choose another location for tie-off. Again, this is a no-no in conventional stringing as it has been known to cause cracks in the racket! Why I still did that is because I am not pulling tension across both grommets, merely tying off a knot. Unorthodox!

Here's the very open 14 mains by 10 crosses stringing pattern! From what I've read online so far, this is still within the rules governing the hitting surface of the racket. So it's legal for competition play! (http://www.itftennis.com/technical/rules/equipment/appendixii.asp)

Playtest:
- stringbed feels extremely soft but not mushy
- very powerful, way beyond rocket launchers and entering into nuclear territory!
- spin is MORE than shaped poly mains!!! Jack's waist-high forehand topspin shots kicked up to my ear level!!!
- control is still very good despite open stringing
- tension holding feels good after about 30 minutes
- needs getting used to the very soft stringbed
- even J who has tennis elbow found this combination very soft and comfortable

(Special thanks to J and J's coach Jack for their feedback after testing this string combination as well)

Update:
A friend who saw the racket was sharp enough to notice another peculiarity. To even out the spacing between cross strings, the second cross from the bottom was actually strung through the grommets for the last mains string! 

Wilson PSC 6.1 + Kevlar/Poly @ 45/45 lbs (14x16)

Since I felt 35lbs was too low tensioned, I thought of increasing it to 45lbs for both mains and crosses.

However, there are two things I wish to address with this "re-string".

First, I could not shake off that nagging feeling of being potentially hurt by tennis elbow should it be harsh. After all, tennis elbow is NOT a minor injury.

Second, I only have one pack of Kevlar strings to experiment and I've already used half of it for this hybrid.

After much thought, without any solution in sight, I decided to "cross over to the dark side" and ventured into unorthodox stringing...

I mounted the racket onto my stringing machine and carefully removed the strings to re-use them! After all, both kevlar and poly are extremely durable. And I don't think they have even started stretching yet @ 35 lbs!

With the shorter length of strings, it is no longer possible to complete the original 16 by 18. I have to change my stringing method. 

I "opened up" the racket to 14 by 16. By skipping both the outer mains and outer crosses, I am able to "soften" the outer stringbed stiffness and yet maintain the stiffness in the centre to preserve control and spin. Best of both worlds!

Note the double tie-off I had to do on the same string (5Top) on the top-left in the picture. This is a no-no in conventional stringing...

While pulling tension, I also noticed that both strings stretched more @ 45 lbs than when I previously strung @ 35 lbs. The amount of string slack I had to provide and the amount the dropweight drops while the strings stretches is evident!

Playtest:
- 45lbs feels significantly tighter than 35lbs
- yet, it does not feel harsh at all, but it feels soft
- it is incredibly low-powered
- control and spin remains excellent only on good hits
- the sweet spot seems to have either disappeared or been reduced to nanometers! (I think Woody is more forgiving!!!)

Wilson PSC 6.1 + Kevlar/Poly @ 35/35 lbs

The ultimate most durable strings I read are Kevlar followed by Polyester. So I thought, how would it play if I hybrid them together?

While I had no doubts on the strings' durability, I have questions about my own arm's resilence to absorb any possible harsh feelings those strings would bring. So, safety first! Drop tension of both mains and cross to 35lbs!

My customised PSC 6.1 weighs 354g before stringing and 368g after. So the kevlar poly hybrid added 14g, which is within the expected norm.

Here's how it looks...

Playtest:
- At 35lbs, it is incredibly soft, low powered with very good control
- Absolutely no harsh feeling of kevlar at all
- It turned mushy and spongy after a few hits but control remains good
- topspin is slightly better than multifilaments
- with flat shots, the sound is like soft gunshot rather than pop
- while playing, I get the feeling that at 35 lbs, the strings have not even started stretching yet!

It's definitely way too soft for me at 35lbs, so off it goes...

...or is it time for some unorthodox experiments?

Strings:

Pro Supex Aramid 50 1.10mm mains @ 35lbs

Pro Supex Big Ace Revo 17g 1.25mm cross @ 35lbs