What's Your Racket 2001/02 ???
Joe Laredo looks at the choice of Manufacturers and Technologies on offer

• Racket Forum  what do you think of your racket, which model do you fancy for Christmas, what do you think of the manufacturers' claims (and prices) ???

• Stringing tips

A couple of years ago, it was titanium; this year there's tungsten and intellifiber. Intellifiber? Head's latest innovation is the use of a material in the racket throat (of the i.110 and I.140 ­ three more "intelligent" models are promised for 2002) that actually changes its properties when it comes under pressure, i.e. when you hit the ball, thanks to the generation of an electrical current (the material is called piezoelectric). It isn't strictly "intelligent" (although Prince's tennis rackets incorporate a micro-chip in the handle) but it stiffens the throat within a millisecond of your hitting the ball and you won't get an electric shock.

Prince meanwhile have added tungsten to their new Warrior racket, albeit a tiny percentage of the total material, which may make an equally small difference to the power you can generate from it. Unsquashable have also come up with a new material, tecnolar (as used in bullet-proof vests!), which is moulded with graphite for a strong but "elastic" frame.

Other manufacturers are using materials you might not associate with squash rackets: nickel and copper, for example, which feature in rackets on offer from Oliver and Grays. Powerbraid is the name given to Grays' combination of these materials in the throat of the new Millennium 130 and Light Blue 135 in order to reduce twist. Copper also crops up in Oliver's Element X and Sabre's new Cobra and Panther rackets. Karakal have added magnesium to the SSL-115 and BSL-120 to give them extra strength, and titanium still features in most manufacturers' ranges, including Browningıs new Stealth Cti and Stealth Ti. Because theyıre heavy, these materials can only be used in small quantities, so most of the frame must still be made of carbon or graphite. But even here, the situation is far from straightforward.

There's now a plethora of carbon fibres, produced by heating various polymers and materials such as coal tar and petroleum pitch. The strength of the resulting fibre depends not only on the quality of the material used, but also on the temperature to which it is heated, which affects the alignment of the fibres. "Low" temperatures (e.g. 10,000°C) produce low strength (and low cost) fibres; high temperatures (30,000°C) high strength (and high cost) fibres, which however tend to be brittle. Ultracarbon is the material Grays use in their racket heads in order to reduce weight in response to demand from players for increasingly head-light rackets.

Ultracarbon is also used by CX Pro Sport in their new Response and Precision, while Unsquashable use a carbon 4 in their new Y-Tec 1200 C4Ti and Fischer "aircarbon" in their M3 150. Oliver claim to use only the best quality materials in their meta-carbon, which features in a range of new rackets and is highly rigid but light (half the weight of titanium, for example).

Similarly, Karakal claim to use the purest graphite, super hi-modulus, in their BSL-120 and SSL-115 and have developed a new construction process called "hot melt", which bonds the fibres more tightly to increase frame strength.

Shapes & Sizes
It isn't only the materials used that determine frame stiffness. The shape or profile of the frame is also significant and several manufacturers opt for a curved cross-section, variously described as concave (Dunlop), C-section (Slazenger), C frame (Pointfore, including the new Hawk), C-X section (Sabre), Power-Groove (Titan's new TT) and Groove Power System (Karakal). This design has the added advantage of effectively elongating the strings to make the trampoline that bit bigger.

An extra 3mm all round provides an amazing 25 sq. cm more string, as with Dunlopıs Custom C-Max and C-Max JP, which claim a "hitting area" of 525 sq.cm (though I'm not sure you'd want to use the extra 25cm2 for hitting). Similarly, Slazenger's C-section frame effectively increases the Pro Carbon 140g's head from 500 sq.cm to 520 sq.cm.

Other big heads (495+cm2) include Head's i.110, QMıs Nexxt, Sabre's Cobra, Fischer's All Court Titanium 160, and CX's Response and Power. There are several other construction methods designed to increase stiffness without adding weight, such as Headıs PowerFrame (i.110 and i.140), a series of "bubbles" in the throat and shaft, and QM's honeycomb of magnesium foam (MG/X004 and MG/X006), introduced last year for a similar effect.

Vibrations
There's a drawback to all this stiffness: extra vibration, which racket manufacturers have devoted yet more time and money to devising ways of reducing or absorbing. QM claim their magnesium foam (see above) reduces vibration and Oliver mix their meta-carbon with resin and use kevlar to the same end. Head maintain that their intellifiber eliminates 20% of vibration "because electrical energy does not create vibrations". (My knowledge of physics isn't up to evaluating this one.)

Other vibration-reducing systems include Dunlop's imaginatively named Squash Ball Vibration Dampener, Sabre's Vibrostep (Tornado) and Fischer's GDS (M3 150 and M3 160), but perhaps the most interesting idea comes from Wilson, whose "triad" system consists of a three-part frame structure, the head and the handle being linked by a section made of shock-absorbing material. Although this innovation hasn't yet made the (inevitable?) transition from tennis to squash, we're told to expect it in the near future (you'll read about it here first.)

Strings
As racket frames become stiffer, racket strings are being asked to work harder and harder to maintain control without sacrificing power (another unattainable ideal). Various string patterns have come and gone over the years; some have gone and then come back again, like Head's PowerPattern, a parallel arrangement of strings with an equal distance between each, just like those old wooden rackets. (It worked well enough for Jahangir...)

Other manufacturers are following Prince's lead with a "fan" string arrangement. Notable among these are Karakal, QM with their new Razzor and CX Pro Sport (soon to be renamed CX Pro Squash), who have relinquished the Goudie brand and launched four new rackets of their own for the 2001/02 season, the top two of which (Response and Precision) feature a "double" main string pattern where all the main strings run right down to the throat. Sabre also have a new four-racket range headed by the Cobra, which features a "double impact" string system. This doesn't mean that you can hit the ball twice but that two strings share one grommet ­ i.e. they're wrapped round the bridge. Wilsonıs new Hyper Rollers Overdrive has a unique frame design featuring a double bridge, allowing the main strings to extend even further towards the throat.

The point at which string meets frame is another area where manufacturers have invested ingenuity in devising ways of maximising the deflection of the strings at each end ­ to increase power and reduce wear. A couple of years ago, Wilson came up with Power Holes with this aim in mind; now theyıve fitted rollers (Hyper Rollers and Hyper Rollers Overdrive), which they claim allow the strings to move by an extra 40%. Head's PowerZone grommets are supposed to allow 80% more deflection than "conventional" grommets, and Sabre's Control Zone is essentially the same idea: enlarged grommets to allow the strings greater flex so that ball stays on them longer to give you more control.

But how much more power does this extra movement give you? Very little, according to the string manufacturers, who reckon that your choice of string type and tension is far more significant.

A number of manufacturers make a point of emphasising the quality of the string they use, including Unsquashable, whose top rackets are prestrung with Tecnifibre 305SPL (Y-Tec 1200 C4Ti) and XTRA D.Ti (Stagger 721 and 921 C4Ti), and Grays, whose premium rackets (Millennium 130 and Light Blue 135) are prestrung with Ashaway Super Nick XL.

Weight & Balance
Another key variable in a racketıs design is its weight. A lighter racket is faster through the air and easier on the arm, but thereıs obviously a limit to how light it can be if itıs going to withstand repeated impact with the ball (and occasionally with other harder objects). Karakal continue to claim the lightest racket on the market with their SSL-115, although Head's i.110 runs it close with a frame weight of 110g. Other new lightweights include Karakal's BSL-120 and MXTi-125, CX's Response and Sabreıs Cobra. (Note that some manufacturers quote weights without strings, grip or bumper strips, others all-up, so you should ask what the figures include when comparing weights.)

Weight isn't an absolute factor, of course; much depends on how the weight is distributed, i.e. on a racket's balance. A head-heavy racket can generate more power than a head-light racket, but only if you have the technique (and strength) to wield it.

Dunlop have come up with an ingenious solution to this conundrum (why has no one thought of it before?): interchangeable handles (Custom C-Max and Custom Tour). Each racket comes with three handles of different weights ­ 10g, 5g and, apparently, 0g (perhaps it's filled with hot air?) ­ so that you can choose the balance that best suits you.

At the end of the day, it largely comes down to finding a racket that suits you and the way you play. (You only have to look at the variety of rackets used by the top players.)

 

• Racket Forum

• Racket Forum
  what do you think of your racket, which model do you fancy for Christmas, what do you think of the manufacturers' claims (and prices) ???

• The only way to know if a string is right for you is to play a few matches with it. Restring frequently and try different strings until you find the one that suits you best.
    
• In general, thin strings are more powerful but less durable than thick ones ­ simply stated thinner strings stretch further on impact with the ball. As they recover from stretch, they propel the ball forward: the more stretch, the more power.
     
• There are two main causes of string breakage. The first is "notching." During a match, the cross strings (the shorter, "horizontal" strings) are pounded hundreds of times against the main strings (the longer, "vertical" ones). That repeated pounding cuts notches into the mains, and eventually, one of the notches becomes so deep that the string snaps. (It's almost always the mains that break.) The second major cause of breakage is overstretching, or tensile failure. While notching occurs gradually, tensile failure is sudden and catastrophic. Overstretching occurs most often on poorly hit shots, when the ball contacts the stringbed near the frame. The string wants to stretch equally on both sides of the ball, but in this situation there's not much to work with on one side. The string stretches beyond its elastic limit and simply snaps.  
    
• Obviously, thicker strings are more resistant to breakage than thinner ones. But because thick strings tend to be less powerful, each player must decide for him- or herself which factor is more important.
    
• "Tune" your racket to suit your playing style, by adjusting the string tension. If you don't like your racket's performance, don't think about buying a new one until you've experimented with changes in string selection and tension.
   
• The basic equations are:
  Higher Tension = More Control
  Lower Tension = More Power
   
• Strings at low tension stretch more when they contact the ball, and then quickly snap back to their initial length. This "trampoline effect" (also known as resilience, or rebound) adds power to the shot. If the racket is strung at a higher tension, there's less stretch left in the string to provide power. On the other hand, tighter strings remain flatter, so it's easier to control the direction of the ball.

• Racket Forum

• Racket Forum