Overhaul: Wilson Hammer 5.8 + Syn Gut @ 32/28 lbs

While this racket has a similar composition of 80% Graphite and 20% Kevlar (link) as the PSC6.1, the feel is very different. 

Of course, since this was designed and built to be a player's stick but with "hammer-style" weight. Literally, it means very head-heavy. Stock balance point is 36cm (14.125").

I've tried multi/poly, full poly, full multi and multi/syn gut in this racket. In all these combinations, two things stand out. 

First, this is a very very stiff frame and off-centre hits punishes heavily with jarring vibrations. Just an hour with this is enough to give me wrist pain and elbow discomfort for a few days. (I estimate my sweetspot contact to be at about 60% with very good players and about 80% with casual hitters.)

Second, when the sweetspot is hit, it reminds me very much of my PSC6.1. I believe there is potential in this racket.

Since I don't think I can up my sweetspot contact percentage, the next best thing, is to deal with the unhealthy vibrations through modifications or tweaks. 

I acquired a frequency meter and was having fun measuring string tension, racket frequency and vibration frequency with it.

Since the main gripe about this racket is the shock, I searched and studied many articles about racket frame frequencies (link) and vibrations (link). 

I decided to experiment with this stick.

At below 300g strung and gripped, the stock frame has plenty of room for customisations. Only the balance is way off.

Before any work started, I recorded all the frequencies I could.

Then I strung the racket so that I could feel the bounce of a ball off the strings rather than just relying on the frequency. I bounced a golf ball instead as the hard outer covering generated more distinct vibrations than the soft felt of the tennis ball.

The last setup was 32/30 lbs (link) and that it felt much tighter than my 16x18 PSC6.1. So I dropped two more pounds on the crosses to make it 32/28 lbs this time.

After stringing, the leather grip is removed. All the lead tape I previously applied on the grip pallet are showing up. It should be around 18g.

The butt cap was taken off and I recall previously stuffing 15g of lead inside the cap. This racket came with the "In-Tune Handle System" and had a piece of rubber protruding from the butt cap. It weighs 14g on its own.

Here comes the most crucial part in this mod. Many rackets are pre-filled with foam in the factory. The objective is to reduce vibrations and add stability.

The pic below shows the stock foam that was filled at the factory.

To change the racket vibration frequencies is to change the overall density. I dug out as much of the foam as I could. Given the years, a lot of the old foam has become dry and brittle. So dry, it feels crispy to the touch.

When the foam is squeezed, it does not bounce back much. I suspect the foam has exceeded its useful life. Here's another look at some of the foam.

Below pic shows the hollow butt with the foam removed.

At every stage, details like the weight, balance and frequencies are recorded to ensure I do not go too far off-track from my plans. The racket is so head-heavy at this point that I had to stand it on its butt to measure weight.

I tried filling the frame with many different types of materials, one at a time, and then tapping the frame and strings and recording the frequencies. 

This is a very tedious and tiring process. The materials must be packed tight, which made it difficult to extricate. But there is no other way I can think of as every racket and material exhibit different frequencies and vibration tendencies.

Some materials made the stringbed feel too dead. Others accentuated the vibrations! Studying the data I collected, and by the process of elimination, I soon arrived at a very narrow frequency range which seems to work well with the frame and the ELT stringbed.

Obviously, I did not have enough hands (...and patience) to take pics of all the different materials I tried. Below pic shows the insertion of polystyrene beads. I bought a few different packs with different densities and tried them all.

Below pic shows the insertion of a mid-density gel-like moulding resin.

After obtaining what I thought was the best possible outcome, I nailed the buttcap back on.

The weight and balance is further fine-tuned before I re-installed the leather grip.

So far, the few simple bounce tests seems promising. The frequency changed and vibrations are also A LOT LESS than when I started. 

Only the acid test remains!

Playtest:
- This modification is a SUCCESS!!!
- Almost ALL of the jarring vibrations have been removed. I deliberately hit the ball around the entire racket frame and the very edges of the stringbed all around. I can feel the mishits. But the previous stinging painful evil vibes are gone!!! In its place is just a low, soft and very short-duration "thud". That's it!
- The sweetspot increased tremendously! Stability improved. I kept total weight and balance very similar to how the frame was before the overhaul. So it cannot be due to weight or balance changes.
- Ball contacts on sweetspot got sweeter. The feel is so pure now that I think it's even nicer than my PSC6.1!
- My confidence with this frame has soared.
- I played almost an entire continuous hour with this, intentionally clobbering every shot at full strength. Exhausted? Yes! Discomfort? Zilch!
- The 7+ hours I spent was totally worth it! Just don't ask me to do it again...
- Ball fur pic below

Rackets, rackets on the floor,

Who's the sweetest of them all?

"It's me, it's me" says the Hammer,

"Oh yes, oh yes, I agree!"

27Apr2013 update:
- I'm still reeling in shock at how well the Hammer 5.8 played after modifications. 
- To confirm my findings, I brought out my best feeling rackets and invited someone with very sensitive hands to try the Hammer. (It's a blind test)
- The Hammer won, hands down. There is just no competition. Neither my PSC6.1 with natural gut, ProStaff 6.0 85 nor the RD7 could match the comfort and feel.
- The absence of "noise" and unwanted vibrations allowed us to feel ONLY what we needed and was supposed to be felt during ball impact.
- Despite the impressive dampening, it does not feel dead, muffled nor suppressed at all. It's actually very lively! 
- The difference is somewhat similar to listening to a symphony orchestra in a park and in a grand concert hall where there is no noise and near perfect acoustics.
- The pocketing is unmistakable. What is different here is I could even tell when the stringbed was depressing and when the stringbed was rebounding.
- Sweetspot hits are extremely clean, quiet and stable. It is not something I have felt in a tennis racket before.
- With such great feedback, learning and adaptability to this stick becomes unusually fast. Simply because it is focused and there is no peripheral noise.
- As usual, my partner wanted this racket. But I'm putting my foot down this time. Definitely not!

Strings:

Pro Supex Synthetic Gut Titan 1.25mm @ 32/28 lbs (varied crosses)

Oldie: Wilson XT-80-L3 + Syn Gut @ 28/26 lbs (varied crosses)

If rackets and strings could speak, I would not be in the dark regarding this racket's make, composition and specs. 

Emails to Wilson were unreplied. Up till now, any online search and appeals could not throw any light on this stick. Absolutely nothing!

I have two of these and I LOVE IT! The few friends who tried them attested that these play better than the legendary Pro Staff 6.0! Yes, the XT-80 was pitched against the St. Vincent, Taiwan and China Pro Staffs and it prevailed. Surprising, unbelievable, sacrilegious... but true!

The previous one (link) in L2 grip size came with broken strings, so I got it strung and played with. But this L3 was a gift from my friend. It came with the original factory strung synthetic gut from perhaps the 80s. (Yes, it was done one-piece bottom-up!) I was reluctant to cut it. But the frame is too sweet to just let it sit in the cabinet.

Eventually, my cutter prevailed...

With only 80 sq inch, I felt 30 lbs was not low enough in the other XT-80. I decided to drop to 28/26 lbs and add a modified proportional stringing for the top few crosses! That would be fancy enough to tickle my "taste hand-buds" I think...

Here's a pic of the XT-80 twins together! They even share the same buttcap code of "KAR"!

Playtest:
- Compared to the other XT-80 done at 30lbs, the pocketing from this is slightly deeper.
- Just this difference is enough to affect my stroke. It's easy to tell when there are two of the same rackets to compare side-by-side with.
- With extra pocketing, how I follow-through my stroke becomes very important. The deeper pocketing means a longer dwell time of the ball on the strings. So if I am lazy, the ball goes long or off tangent.
- It is not inaccurate. I would attribute this more to a timing issue. When accustomed, I had absolutely no problems aiming my shots or serves.
- Compared to natural gut, the strings rebound feels delayed. I don't recall having this "problem" with gut whose pocketing is much much more deeper.
- Other than this, everything else plays very similar to my previous XT-80 done at 30lbs.
- For now, I think I prefer the 30lbs tension. Will try again and see how it plays after clocking a few hours of hits.
- Ball fur pic after only about 20 minutes of rally.

30Apr2013 update:
- I noticed even with ELT, the strings have a break-in period. I always enjoy the string better from the second session of play. So here it is!
- Pocketing did not get any deeper than previously but the overall stringbed did feel much more even and friendly.
- Spin is absolutely, ridiculously, incredibly aplenty! Even when I tried to hit flat with less spin, the ball still kicked up to my partner's shoulder.
- The low cross tension, coupled with proportional stringing really allowed free sliding of the mains. Just a few shots would see quite big gaps in the mains due to string movement. 
- I can even hear the strings "crackling" during my follow-through brushing.
- Power is lower than at 30lbs. Whenever I try to let one rip, the stringbed simply absorbs the power. Unless I do a open-faced badminton style forehand, it is difficult to hit the ball out. There is just either too much topspin or a little too low power for me.
- Volleys are very very nice.
- Flat serves are still good although I preferred slightly less pocketing. I had to reduce some power and hit a little more more gently. Second serves almost always elicited vulgarities from the receiving party.
- There's so much ball-grab that yet another ball's fur was violently ripped off.

- The repeat sliding of the mains has created a dark spot in the middle of the stringbed in merely two sessions of tennis. Good for monitoring my ball contact area.

06May2013 update:
- I hit with some new balls using this racket.
- The thick coat of fur provided extra grab for the strings. Spin increased so much that I had problems clearing the net from my baseline. The ball simply curled down my side. So I had to hit almost completely flat.
- Even then, the ball naturally carried topspin. Both my partner and I could see the ball spinning before and after the bounce.
- My partner tried too. It was impossible to hit completely flat shots. We could not do it at all. Even the slightly brush would magnify the spin levels.
- Pocketing is very deep and comfortable. Rebound is slightly delayed though.
- The sweetspot remains huge.
- The only dis-satisfaction I have is way too much spin and too low power.
- Just for the record, this racket currently weighs almost 370g with a 32.5cm balance. Swingweight is at least 350+, maybe 360+. 
- With such a powerful stick, it is ridiculous that both of us struggle to even clear the net from the baseline! Just way too much spin!
- I'll have to bring the tension up slightly next round...

11May2013 update:
- Spin serves are so good with this tension setup that I am willing to tolerate the very low power and occasional mishits.
- However, after this racket exceeds its 10th hour of play, directional control seems to be going downhill fast.
- The rebound from the deep pocketing is also lagging more and more.
- I have to admit that 28/26 lbs plus proportional stringing in the crosses is pushing the boundaries for control.
- But, but, but... spin serves are really really that good!

Strings:

Pro Supex Synthetic Gut Titan 1.25mm @ 28/26 lbs (varied crosses)

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

Wilson PSC 6.1 + Natural Gut/Syn Gut @ Cross Re-do

My last session of tennis was unusually gruelling.

That day, my partner was very well rested and well fed. From the first few hits, I knew he wanted some serious hitting. So, I picked my preferred weapon - the heavily leaded 370g+ PSC 6.1 with the NG/SG combo.

It was a cloudy, early morning. Cool and refreshing. But in less than 20 minutes of rallying, my shirt was completely soaked. Sweat was even dripping from my sleeves and there was plenty of droplets around the baseline.

As he stepped up the pace, I matched him and returned tit for tat! When he hit crosscourt corners, I drove the ball deep down the line with heavy topspin. When he dropped, I lobbed. We were totally spent after an hour.

Towards the latter half, I noticed a gradual drop in my racket's power and directional control. I attributed it to fatigue and continued using the racket.

But something about the stringbed just felt very very different! I got another partner to try it and the answer became apparent immediately!

The synthetic gut is dead!

It was easy to diagnose. I took the freshly strung RD7 (link) with only about an hour's worth of use as a benchmark. The RD7 fullbed synthetic gut was fresh, lively and very crisp. The stringbed was responsive. Pocketing was deep but rebounded fast and very consistently.

The PSC6.1's stringbed felt very flat, lifeless and low-powered. Ball contacts felt "murky" and mushy. It was like hitting with deflated tennis balls.  Rebounds from pocketing felt delayed and reluctant. Totally uncharacteristic of natural gut! Little wonder since I've used this for about 10 hours.

So?

After removing the crosses, I examined the natural gut carefully. Not much notching but it is very very dry. I read that coconut oil was used to lubricate the string during the manufacture process. 

So I took some and smeared it along the mains. After sitting for about 15min, I wiped the strings down with a clean piece of tissue.

Then I weaved the crosses with a fresh set of synthetic gut at only 28lbs. This tension was decided based on the frequency of the re-used mains.

I measured the racket's length and hoop width before and after cutting the old crosses, and also after re-doing the crosses. There was very little distortion. So far, I have been relying on this frame distortion as a gauge to select tension and it seems to be working very well.

Just bouncing a ball off the ground, I could already feel the breadth of new life in the strings. The deep and powerful pocketing of the gut surfaced again. The comfort, stability and total absence of vibrations is so addictive. And the crispness came back too!

Playtest:
- Yes! I think the re-done crosses worked very well.
- All the usual characteristics of the stringbed that were present in the previous stringjob came back - power, spin, control and comfort.

Yonex RD7-UL2 + Syn Gut @ 32/30 lbs (Varied Cross)

Through some sheer coincidence, and a little dose of luck, I came to inherit a very good conditioned Yonex RD7. This would be the third RD7 I'm working on this month alone.

With rackets of this age, naturally the original grip has crumbled. Grommets would be worn. Any original strings would need re-stringing as well.

Even though I've already strung two RD7s for M, but upon googling, I discovered something interesting I never knew before. (Or perhaps I've not been paying attention....)

The weight and recommended string tension of the RD7 rackets are tied-in to the grip sizes of the racket. So different grip sizes actually means different racket weights and different tension ranges.

Below specs are extracted from this link:

Head Size : 95 sq in
Construction : 22 mm Flat Beam
Length : 27 in
Composition : High Modulous Graphite
Weight :
4 1/8   9.9 - 10.6oz
4 1/4 10.6 - 11.3oz
4 3/8 11.3 - 12.0oz 
4 1/2 11.3 - 12.0oz 
4 5/8 11.3 - 12.0oz
String Tension : 
4 1/8 45 - 55 lbs
4 1/4 50 - 60 lbs
4 3/8 55 - 65 lbs
4 1/2 55 - 65 lbs
4 5/8 55 - 65 lbs
String Pattern :
16 Mains /19 Crosses
One Piece
Mains skip 8T,8H
No Shared holes

Since I am customising this for a lady, I decided to start-off with a fullbed ELT syn gut. My past experience with dropping two pounds on the crosses seemed to play well. And Yonex did use to recommend a 5% lower tension for the crosses, so I will pull the cross to 30lbs.

To further maximise the sweetspot, I will also use a modified proportional stringing tension differential for the shorter few cross strings. I recall the top one-third of this frame tends to play a little harsh on M's sticks.

I'm doing this one-piece. So I'm leaving the last mains and starting on the second cross from the top.

Filling the last mains at 32lbs.

Pulling tension on the last string - the top cross.

Done.

Playtest:
- This is a polarised frame.
- Spin is incredible. It is so easy, almost natural to "whip" the racket with the bulk of the weight at extreme ends.
- Surprisingly, for something with flex 54RA, it still plays very powerfully! Deep baseline shots poses no problem at all.
- Whether hitting flat or with heavy spin, the racket and stringbed is accurate.
- M's rackets were both strung at 35/33 lbs and I could feel the racket flex when receiving certain hard flat shots. However, with this fullbed syn gut at only 32/30 lbs, the stringbed pocketing absorbed most of the power. I could not recall any instances of the racket flexing.
- Below pic shows the string movements and ball fur.

20Apr2013 update:
- This is the second session of play and the stringbed has already settled-in and stabilised.
- The varied crosses performed very well indeed. Contacts near the top did not produce any jarring vibrations at all. It was just a weak shot that barely got over the net.
- The RD7 has a decent swingweight. Coupled with ELT, my lady partner had no problems at all sending the ball from baseline to baseline with good control. This is not the kind of "trampoline power" one would expect from low-tensioned strings.
- The strings have gone through 3+ hours of use.
- This setup is staying!

Strings:

Pro Supex Synthetic Gut Titan 1.25mm @ 32/30 lbs
(proportional tension on short crosses)

Dunlop Mfil300 + Syn Gut @ 32/30 lbs (one-piece)

After coming back to playing tennis, I met with many different players. All, except one, are wielding very stiff and light weight rackets. Their movements and racket preparations for forehands and backhands seem SO FAST!!!

I feel like a dinosaur playing with them! Both in terms of my preference for near extinct oldies and perhaps my clumsiness with 370g (13oz) frames.

Peer pressure is huge. Every Tom, Dick and Harry is telling me my rackets are passe. 

"Get some new weapons!" 
"Come, try my Babolat!"
"You are not Pete Sampras! Stop trying to use such heavy rackets!"

.... blah blah blah...

So I succumbed and got a lightweight Dunlop Mfil300. Stock weight strung is about 310g. Touted to be highly maneuverable, with great feel and packs a punch. 

Okay! Now I'm suitably equipped! Let's see if I can scare Federer with some ridiculously-paced passing shots. Or "out-whip" Nadal and give him a taste of some REALLY insane topspin with my blending-machine-styled forehand! 

Stringing pics below.

Playtest:

- The string tension is very appropriate. All the usual elements like pocketing, spin, power and comfort are all present in huge quantities.

- Of the above four aspects, spin really stands out. Even without "whipping", the ball already kicks up high. I can see my partner took most of the shots at head-level about 2-3 metres behind the baseline!

- When I really let one go, the topspin added so much speed to the ball that they were clear winners.

- I added about 10g split around 12, 3 and 9 o'clock. Another about 15g is added to the racket handle and butt.

- I can definitely feel it is the polarised weight setup that equips this racket for immense spin. The spin prowess way exceeds my usual non-polarised PSC6.1 (link) or the XT-80 (link). So now I know how a polarised racket generates spin.

- At this lightweight (about 340g), the racket moves very fast. I can take the ball very early, almost like a half-volley.

- The few things I did not like are the lack of stability, especially when receiving very hard flat shots and the twisting from even very slight off-centre contacts. I think I am just too used to heavy sticks.

- And no, I definitely did not attract any special attention. Not even from the retirees playing next court, much less from Federer or Nadal... 

- I'll stick with my "old faithfuls"...

Strings:

Pro Supex Synthetic Gut Titan 1.25mm @ 32/30 lbs

Yonex RD7-SL3 + Natural Gut/Syn Gut @ 35/33 lbs

This is the other RD7 I am doing up for M. (link1)(link2)

Having tried an extremely low-powered strings setup, I will swing to the other extreme and give this a high-powered strings setup.

What else can it be?

Natural gut is a very beautiful string. There is this translucent golden yellow glow when light shines on it. It's absolutely captivating!

If you like kinky stuff, try stringing natural gut!

After the usual unravelling and pre-stretch to lessen the coil memory, it's off to work.

Halfway through, the gauge seems to feel quite thick for a 17g. So I measured it and it came out right at 1.25mm. Klip Legend is a very good quality, consistent and high-end gut for an affordable price.

The melodious tune from pinging the completed main strings cannot be ignored. When a string is plucked, the resonance stays and the beautiful sound reveberates around the racket! Kind of makes me think I'm stringing a harp sometimes!

I don't have perfect pitch. But only with natural gut, the centre few main strings share a very similar frequency when compared to other strings. This demonstrates the impressive tension stability of natural gut over synthetic strings.

Playtest:
- At low tensions, even with pre-stretch, there is a break-in period needed for natural gut. I haven't found the exact mark yet, but it definitely plays better after 15min. At 30min, the pocketing feels deeper. And comfort at 45min exceeds levels at 30min.
- Power levels are very good and there is absolutely no trampoline.
- When "whipped" deliberately, adding huge amounts of offensive topspin is no problem. With ELT, spin can be stepped-up at will.
- One impressive feature about ELT natural gut is the ease of "returning the power" from a hard-hit ball back to the opponent. No hard swings needed. Just a firm hold and a tap on the sweetspot and off it goes.
- The few deep corner shots which I thought were clear winners were "tapped back" to me with almost full power. My power!
- We are still fine-tuning and matching both RD7s. Some very unorthodox work involving drills and grinders may be carried out.

Strings:

Klip Legend Natural Gut 1.25mm mains @ 35 lbs

Pro Supex Synthetic Gut Titan 1.25mm crosses @ 33 lbs