1 - European Racquet Stringers Association

RacquetTech
October - 2009
Wimbledon
Ashaway ZyMax
New Racquets
Dunlop - Tecnifibre
Industry News
Prince Has
Discovered A New
Source Of Energy.
Plug Into It.
And Turn On Your Game.
Gael Monfils plays
the
Rebel.
Introducing
Puts More Energy Where
You Want It — Into Your Shot.
Available in four distinct models for different player types.
Demo An
Today.
princetennis.com
ENERGY WHERE IT MATTERS
Contents
RacquetTech IV
20 Industry News
Head Radical Messenger
Head Golden Ball
Prince Triple Win
Prince Premier LT Nr. 1
Dunlop Scouting Tour
Tecnifibre & Sixth Sense
PTR German Certification
Bow Brand Natural Gut
Featured Articles
3
5
10
13
15
27
My Serve
New Products
Ashaway ZyMax
String Test
Wimbledon
Rod Cross
Racquet Tech Europe
European Racquet Stringers
Association
My Serve
DIRECTOR
Mark Maslowski
We have a lot of organizational news this month. The new
Stringers Digest 2009/10 is being prepared for publication. The
new format is an A4 book instead of a ringbook. Please renew your
membership if it has expired to get the latest issues of RacquetTech
magazine and the new Digest.
The 2010 Annual Meeting/Symposium is planned for the
end of October in southern Spain. We will keep you informed of the
exact dates and venue. The meeting is planned for three days with
workshops covering different areas such as stringing, racquet tuning, marketing, etc.
In 2010 ERSA will publish 6 magazines starting with February 1, then every 2 months. We have several new experts writing
articles for us in 2010, along with a Questions and Answers Section
and Stringing Tips in every issue. The six issues will allow us to offer
more space for information for our members.
We have been busier than ever with workshops. We are
booked out through the end of this year and already have workshops (20) for Italy, Greece, England, Ireland and Germany planned
along with the workshops offered by our testers in five countries.
In tennis racket sales, the industry is still down, but stringingseems to be steady. It will be interesting to see how Klip USA and
Pacific will fit into the market in these slower times as “new” racquet
manufacturers.
Bow Brand has also just announced it is going back into
natural gut production for tennis after a short break.
Bow Brand is a major producer of natural gut music strings.
The new Tecnifibre stringing machine will be introduced in
the next issue with many improvements and innovations.
Best wishes
Mark Maslowski
Director
Deutsch
Wir haben diesen Monat viele organisatorische Nachrichten. Der neue Stringers Digest
2009/10 wird für die Öffentlichkeit vorbereitet.
Das neue Format ist ein A4 Buch anstatt ein
Ringbuch. Bitte erneuern Sie ihre Mitgliedschaft,
wenn Sie abgelaufen ist um die neuesten Themen über RacquetTech-Magazine und dem
neuen Digest zu erfahren. Das Jahreshauptversammlung/ Symposium 2010 ist für das
Ende vom Oktober in Süd-Spanien geplant. Wir
werden Sie mit den exakten Datum und dem
4
OFFICE MANAGER
Sanda Maslowski
AUSTRALIA MANAGER
Anthony Aley
UK MANAGER
Sam Chan
SPAIN MANAGER
Richard Parnell
GREECE MANAGER
Petros Biris
GREECE WORKSHOP MANAGER
George Pahiakos
Czech Republic & Slovakia
Vaclav Smat
FOUNDING MEMBERS
Ashaway Babolat
Head
Isospeed
Kirschbaum
Luxilon
Pacific Wilson
COPORATE MEMBERS
Ashaway Head
Prince
Völkl
Fischer
Dunlop Slazenger Carlton
STRING SUPPLIER MEMBERS
Apollo Leisure Bow Brand
Kirschbaum
Gosen
Klip Europe
Signum Pro
TOA Strings
Technical Consultant
Rod Cross
CONTACT
European Racquet Stringers
Association
Lenaustr. 38
40470 Düsseldorf, Germany
Phone - +49-(0)211-87511548
Fax - +49-(0)211-87511549
www.ersa-stringers.com
Racquet Tech - October- 2009
My Serve
Austragungsort informieren. Das Meeting ist für 3 Tage mit verschiedene Workshops wie z.B. Bespannen, Schlägertuning, Marketing, usw.
In 2010 wird ERSA 6 Magazine, beginnend am 2. Februar und dann alle 2 Monate, veröffentlichen. Wir haben
etliche neue Experten, die für uns 2010 Artikel schreiben, zusammen mit Fragen und Antwort-Sektion und Bespannungstipps in jeder Ausgabe. Die 6 Ausgaben werden uns mehr Platz für Informationen für unsere Mitglieder ermöglichen. Wir waren nie zuvor so tätig was Workshops angeht. Wir sind bis zum Ende des Jahres ausgebucht und
haben bereits Workshop(20) für Italien, Griechenland, England, Irland und Deutschland geplant, plus Workshops
angeboten von unseren Testern in allen 5 Ländern.
In Tennisschlägerverkauft ist die Industrie immernoch abgesunken aber Bespannen scheint stabil zu laufen. Es wird
interessant sein zu sehen wie Klip USA und Pacific in diesen langsamen Zeiten als „neue“ Schlägerhersteller passen.
Bow Brand hat eben auch angekündigt, dass es wieder geht in Naturdarmproduktion für Tennis. Bow Brand ist ein
bedeutender Naturdarm Musiksaiten Hersteller.
Die neue Tecnifibre-Bespannungsmaschine wird in der nächsten Ausgabe mit vielen Fortschritten und Innovationen
vorgestellt.
Mit freundlichen Grüßen
Mark Maslowski
®
SPIKY SHARK
The Kirschbaum SPIKY SHARK based on ten
years of know how of the SUPER SMASH
SPIKY with its diagonal surface structure. The
new SPIKY SHARK is equipped with an octagonal profile parallel to the string. Using a
specially developed technique we accomplish
distinctive peaks for an optimum grip to the
ball to ensure best slice and spin transfer (US
Patent 6,117,383).
Kirschbaum SPIKY SHARK – a new meaning of
spin transfer!
– no string slipping
– enlarged acceleration and high comfort
– best spin transfer
(available in 1,25 mm / 17 and 1,30 mm / 16,
12 m- und 200 m-unit)
THE STRING WITH A BITE
NEW
Kirschbaum Sportartikel GmbH · Schweerstraße 1 · D-58456 Witten
phone: +49 (0) 23 02-9 70 50 · fax: +49 (0) 23 02-7 76 76
www.kirschbaum-strings.de · [email protected]
New Productss
Specifications
Weight
Head Size
Balance
Swingweight
Pattern
Length
Beam
Stiffness
Gripsize
This racquet was designed
for a serious player (12 – 15
years) or intermediate player
looking for a light stable
frame . Player type is a
steady baseline player . This
racquet comes with a full
racquet cover,
Multi-filament string, Tec
Dry grip and a logo Dampener. It is available in grips 1
through 4.
Unstrung
255g
660 cm²
330mm
272 Kg/cm²
16 x 19
68.5cm /27”
23 mm
70 RA
0,1,2,3
Specifications
Weight
Head Size
Balance
Swingweight
Pattern
Length
Beam
Stiffness
Gripsize
6
Tecnifibre has added 2 new
racquets to the T-fight line
for younger serious players
looking for a light player’s
racquet with new great new
cosmetics.
The lightest racquet in the
T-fight range, combining
power and maneuverability. It was designed for a
young serious player (11 –
13 years) playing a steady
game at the baseline. The
racquet comes with a full
cover, multifilament string,
Tec Dry grip and logo dampener. It is available in grip
sizes 0 through 4.
Unstrung
280g
615 cm²
335mm
280 Kg/cm²
16 x 19
68.5cm /27”
21.5 mm
67 RA
1,2,3,4
Racquet Tech - October- 2009
New Products
DUNLOP’S NEW TENNIS RANGE FOR 2010
With top level pro’s using Dunlop’s rackets including Wimbledon champion Jamie Murray, James Blake and
Roland Garros Ladies Semi-Finalist 2009 Dominika Cibulkova - Dunlop has reaffirmed its position at the
forefront of tennis equipment innovation.
‘Aerogel’ is known for being one of the lightest and strongest materials in existence. In 2009, Dunlop was
the first manufacturer to incorporate 4 directional braided materials into tennis rackets when launching
the 4D range. The new technology perfectly complimented the raw power of Aerogel by enhancing frame
stability and control.
For 2010, Dunlop has refined the Aerogel 4D rackets and has introduced key models to complete the range.
The Aerogel 4D series now features rackets for all player levels and in a variety of specifications making it
the ultimate premium range of tennis rackets on the market.
Some of the key rackets from the range include:
Aerogel 4D 2HUNDRED SERIES
The Aerogel 4D 2HUNDRED is best known Dunlop player frame and is constructed using 100 % premium
graphite, combining Aerogel and 4D Braided technologies which improve the stability of the racket. Used by
Czech tennis star Tomas Berdych, the 2HUNDRED is designed for tournament and advanced players with a
long powerful swing who require exceptional touch and feel.
The Aerogel 4D 2HUNDRED TOUR is the
heaviest racket in the 2HUNDRED series
and is designed for advanced players
who prefer the feel of a heavier frame
but who also require a solid, stable,
control oriented racket.
To complete the series the Aerogel
2HUNDRED 16 X 19 is designed for
advanced players with a long swing who are looking for more response and spin.
Aerogel 4D 3HUNDRED SERIES
The Aerogel 4D 3HUNDRED, used by Tommy Robredo, is the designed for advanced players and good club
players who are looking for touch and feel from a light weight racket.
The Aerogel 4D 3HUNDRED TOUR has been developed with James Blake (Best ATP Tour Ranking 4) to
8
Racquet Tech - October- 2009
New Products
perfectly suit his requirements and is the
ideal racket for competitive players with
a long aggressive swing who also require
exceptional response and control.
This racket is also used on tour by Jurgen
Melzer.
Completing this series, the Aerogel 4D
3HUNDRED LITE is designed for good club
players or advanced junior players who
require plenty of control in a light weight
frame that is manoeuvrable and allows for easy power generation.
Aerogel 4D 5HUNDRED SERIES
The Aerogel 4D 5HUNDRED TOUR offers all the great frame playability of the 5HUNDRED but with extra
weight and control to suit aggressive players of all levels. The racket is used by leading players including
Nicolas Almagro, Ross Hutchins and Jamie Murray.
The Aerogel 4D 5HUNDRED has the perfect blend of control and power and is the ideal racket for players of
all levels.
The Aerogel 4D 5HUNDRED LITE is suitable for those who require an ultra light weight racket and is for
players of all levels.
Aerogel 4D 7HUNDRED SERIES
The large headsize means there is more
surface area to hit the ball with, making
this the ideal racket for those looking to
improve their game. Vibrocore is added
into the throat to reduce the risk of
vibration and the threat of tennis elbow.
Aerogel 4D SUPER-LITE
The SUPER-LITE is used by women’s top 20 player Dominika Cibulkova and is designed for players of all
levels who desire a super light racket with the perfect blend of control, comfort and power.
9
Racquet Tech - October- 2009
Ashaway ZyMax
Ashaway ZyWeaVe
Technology
Ashaway Racket Strings has developed a new core construction
technique that allows the production of lighter, stronger badminton
strings than any yet produced. ZyWeaVe™ technology allows Ashaway
to produce a string that is 25% lighter than standard 0.70mm
badminton strings. The company has introduced a new line of strings
using the new technology under the brand name ZyMax®.
“Professional players like lighter strings in their racquet heads for more
power on smashes and better feel and control on touch shots,” said
Steve Crandall, Vice President of Marketing for Ashaway. “Early play
testing of the new line has been very positive, and one player, Ruilin Huang, even won the 2009 US
Open Ladies Doubles Championship using one of our new ZyMax strings.”
Using a combination of high-tech materials and their proprietary ZyWeaVe core, the new Ashaway
strings produce less elongation at professional stringing tensions and less creep. This means the strings
maintain tension and consistent maximum performance throughout their playing life. In addition,
ZyWeaVe technology allows Ashaway to make a string that can be strung at unusually high tensions.
“We’ve been able to string a ZyMax .70mm gauge string at over 40 lbs. using special high tension
racquets,” said Crandall. “You can tell the string is maintaining tension and repulsion power by the nice
crisp “ping” sound it makes when you strike the shuttle.”
Crandall did not disclose details of the new ZyMax string line, but indicated it would consist of several
gauge models and would be rolled out during the late summer and early fall of 2009. And he added,
“With this technology, we’re confident we can produce the lightest and strongest badminton strings ever
made.”
Ashaway Introduces ZyMax® 70 for Badminton, the Strongest 0.70 mm
String Ever Made
Ashaway Racket Strings has introduced the first string
of its highly anticipated ZyMax® line of badminton
strings. ZyMax 70 makes maximum use of Ashaway’s
patented new ZyWeaVe™ core processing technology
which produces thinner, stronger strings. According
to Ashaway, ZyMax 70 is the strongest 0.70 mm
string ever made. Designed to provide durability and
responsiveness at all stringing tensions, ZyMax 70 is
ideal for heavy hitters who want a micro-gauge string
but need to maximize durability.
“ZyMax 70 is the workhorse of the new line,” said
Steve Crandall, Ashaway’s VP of Marketing, “Power
10
Racquet Tech - October- 2009
Bow Brand
International Limited
At the heart of
performance, playability and control
Play a natural gut string from Bow Brand
and play 100 years of manufacturing excellence
from a world leader committed to technical
innovation.
Play a natural gut string from Bow Brand
and be assured of a first class technical support
service.
Play a natural gut string from Bow Brand
– set your pulse racing…enjoy life!
Bow Brand
International Limited
Official Stringers To The Championships, Wimbledon
Highgate, Kings Lynn, PE30 1PT, UK
+44 (0) 1553 772943
[email protected], www.bowbrand.co.uk
For more information contact
T: + 4 4 ( 0 ) 1 5 5 3 7 7 2 9 4 3
W : w w w. b o w b r a n d . c o . u k
Ashaway ZyMax
players typically use thicker strings to avoid breakage, and increase
tension to improve control. But with ZyMax 70, they can get a thin
string that is both durable and can handle high tensions. ZyMax 70
has performed well in play tests at 40.6 lbs in a special high tension
frame.”
Key to the performance of the ZyMax line is a combination of high-tech core and braid materials, and
Ashaway’s proprietary ZyWeaVe core process technology which allows the production of lighter, stronger
badminton strings than any yet produced. The new ZyMax strings produce less elongation at professional
stringing tensions and less creep. This means the strings maintain tension and consistent maximum
performance throughout their playing life. In addition, ZyWeaVe technology allows Ashaway to make a
string that can be strung at unusually high tensions.
Recommended to be strung at up to 35 lbs, ZyMax 70 is very durable and
responsive across a range of stringing tensions. The ZyWeaVe core allows
less elongation at all stringing tensions. As a result, ZyMax 70 strings up
tighter and plays firmer with maximum tension stability. It maintains string
tension longer and displays consistent maximum performance throughout the
life of the string.
Website: http://www.ashawayusa.com
String Test Badminton
ASHAWAY ZyMax STRING TEST
Ashaway has introduced a new badminton string which has given us
the highest marks of any badminton string we have tested. They spent
the last 18 months developing this string with the goal of making the
best badminton string in the world. The string was developed for good
amateur to professional level players, so we tested the string with 25
top juniors, seniors and high level nationally ranked players in several
countries. As expected, most of the players were using the number
one played string among professional players, but found the ZyMax the
same, somewhat better or much better than the string they now use.
Ashaway has sent us 25 sets of each of 2 of their new ZyMax
badminton strings to test at the same time, Ashaway ZyMax 70 (optic yellow) and ZyMax 67
(platinum silver).
Ashaway ZyMax62 – is a multi-core string with a double multi-filament overwrap at 0.62mm
the thinnest string available. It comes optic yellow,platinum silver and ivory white colors and is
available in 10 meter sets and 200 meter reels. The ZyWeaVe core was developed to maintain
tension over a longer period of time.
Ashaway ZyMax67 – is a multi-core string with a double multi-filament overwrap and is
0.67mm. It comes in optic yellow,platinum silver and ivory white colors and is available in 10
meter sets and 200 meter reels. Recommended tension up to 30 pounds.
Ashaway ZyMax70 - is a multi-core string with a double multi-filament overwrap and is
0.70mm. It comes in optic yellow,platinum silver and ivory white colors and is available in 10
meter sets and 200 meter reels. Developed for more durability and has a recommended tension
up to 35 pounds, but has been tested at over 40 pounds.
We received 25 sets of the ZyMax 70 and ZyMax 67 measuring 10 meters in yellow and silver.
We sent one of each of the sets to 25 testers. We received results from 20 testers.
STRINGING
Almost all of the testers found both strings the same to string as their current string, with 2
finding it somewhat easier and one finding it somewhat more difficult to string. No one reported
any problems with stringing, friction notching, ease of stringing, tying knots, string breakage
and weaving.
PLAYTEST
Playability was rated the same as their string (10 testers) a little better (5 testers) much better
(4 testers) and a little worse (1 tester). The average playing time was 16 hours with the longest
40 hours. Two strings broke during the play test. One from a mishit (10 hours) and the other
from wear (35 hours). Here are the results of the two individual strings.
13
Racquet Tech - October- 2009
New Products
RATINGS
From the chart below you can see that our testers rated the ZyMax 70 Optic Yellow
better in durability and power while the thinner string ZyMax 67 Silver
rated better in feeling, control, comfort and overall playability as you
would expect.
1 being the highest score and 6 being the lowest
playability
durability
power
control
comfort
feeling
tension loss
string movement
ZyMax 70 Yellow
2,2
2
1,9
2,6
3
4
2,3
2,2
ZyMax 67 Silver
2,3
2,4
2,4
2,1
2,8
2,1
2,4
2
Comments –
“A very good playability with both strings.” Top 50 nationally ranked player using Yonex
BG65.
“A very good string with excellent playability” Top 10 nationally ranked player using Head
Super Power 69.
“I rate it a somewhat better than my current string.” Tournament player using Yonex BG65.
“Very good string but I will stick with my string.” Regionally ranked player using Yonex
BG65.
Summary – Ashaway ZyMax Badminton strings should become one of the top strings in the
market in a short time. The UK Ashaway distributor, Goode Sports, said they are selling very
well and better than they hoped for shortly after intoducing it. Zymax came out as good or
a little better in comparison to Yonex BG 65, the most used string from tournament and top
world class players. All the testers said they would carry the string in their business and more
than 50% of the players said they would consider changing to this string even though they
have contracts with other companies.
14
Racquet Tech - October- 2009
Wimbledon 2009
Apollo Leisure has taken over the Wimbledon
stringing service. Below is a report sent in to us with some
interesting information and statistics. See page 18 for
selected player logs.
APOLLO LEISURE REPORT ON WIMBLEDON 2009
Apollo Leisure was honoured to be asked by the All England Club to run the
stringing service at Wimbledon in 2009, taking over from Bow Brand who had
run the service for over 20 years.
We employed 20 stringers, 7 admin staff and 5
runners during the Qualifying Tournament and
the Championships.
We used 10 new Prince 6000 stringing machines.
A Prince Precision Tuning Centre for customising
players’ frames and a Beers ERT 300 tension
tester for checking the dynamic tension of
specific restrings.
The booking in system was computerised for the
first time and although there were some teething
problems this was considered a success.
We strung a total of 2316 frames during the 3
weeks of the Qualifiers and the Championships. A
new record!
The busiest day was the first Monday, 22nd June,
when 286 frames were strung.
The highest tension strung was 33 kgs/73 lbs for
Jurgen Melzer.
The lowest tension strung was 16 kgs/35 lbs for
Peter Luczak.
The most frames strung for one player was 55 for
Serena Williams.
The most popular string was Luxilon Alu Power.
15
Racquet Tech - October- 2009
STARS OF
TOMORROW
The Tennis Europe Junior Tour is the leading pan-European competitive forum
for junior talent in any major sport. Jonathan Jobson reports
F
rom its earliest tournaments into the
1970s and its official creation in 1990,
the Tennis Europe Junior Tour has
come to be universally recognised as the best
starting point for a successful career in tennis.
A string of world #1s, from Ivan Lendl and
Steffi Graf to Roger Federer and Justine
Henin chose this path, alongside nonEuropeans such as Lindsay Davenport,
Lleyton Hewitt, David Nalbandian and Andy
Roddick, all of who had an early taste of success on the courts of Europe’s premier junior
events.
The increasingly professional
organisation of
the tournaments
has meant that the
Tennis Europe Junior
Tour effectively serves
as a dress rehearsal for
life as a professional
tennis player, with
a cumulative ranking system, a seasonending Masters tournament, Player of the
Year awards, online ranking information,
calendars and the playing records of potential
opponents.
The Tour has expanded from
43 tournaments in its first year
to over 300 annual events for
players of age categories 12, 14
and 16 & under. Care is taken
that the focus is not solely on
performance, with sightseeing
tours, players parties and educational events held in tandem,
ensuring a social and informative aspect to tournaments which
allows players to focus on more
than just their tennis and provides an excellent opportunity to
learn about anti-doping, nutrition
and training patterns, to name just
a few topics.
Team events are some of the
highlights of the season, as top
players earn an early chance to
The Tennis Europe Junior Tour has proven to be
a fruitful training ground for world-class players
such as Novak Djokovic and Ana Ivanovic.
represent their country at prestigious championships such as the Tennis Europe Winter
Cups by HEAD, the European Summer Cups
and the Tennis Europe Nations Challenge by
HEAD. July’s European Junior Championships is without doubt the most soughtafter prize for individual players, as past
champions such as Novak Djokovic, Arantxa
Sanchez-Vicario, Martina Hingis and Boris
Becker can attest.
As the tour goes from strength to strength,
so does its appeal. Some 350,000 spectators
attend Tennis Europe Junior Tour events
each year to see around 10,000 young
talents from over 100 countries take their
first steps on the international tennis
stage. Aside from extensive coverage at
TennisEurope.org, reports about the Tour in
over 780 newspapers and magazines and
over 12,000 minutes of annual radio and TV
airtime ensure that every day, people are learning about the latest players to follow in the
footsteps of stars like Rafael Nadal, Andrew
Murray, Ana Ivanovic and Maria Sharapova in
celebrating some of their earliest successes on
the Tennis Europe Junior Tour.
Tennis Europe Junior Tour
1 GAME
1 TOUR
1 CONTINENT
43 ORGANISING COUNTRIES
282 TOURNAMENTS
7320 VOLUNTEERS
10000 PLAYERS
25936 MATCHES
190000 TENNIS BALLS
354200 SPECTATORS
PARTNERS OF THE TENNIS EUROPE JUNIOR TOUR
RECOMMENDED
BALL
tenniseurope.org
RECOMMENDED
TRAINING COMPUTER
OFFICAL
PLAYER DEVELOPMENT PLATFORM
ADIDAS/PAUL ZIMMER
12 & UNDER l 14 & UNDER l 16 & UNDER
BabolatPureDrive+
PrinceO3SpeedportBlack
PrinceO3SpeedportBlack
PrinceOzoneTour
WilsonKͲBlade
DunlopAerogel300
WilsonKͲSixOne95
HeadPrestige
HeadPrestige
HeadRadicalMP
TecnifibreT.Fight320
HeadRadicalMP
HeadExtremePro
YonexRDiS100
HeadRadicalMP
HeadExtreme
WilsonKͲBladeTour
BabolatAeroStorm
BabolatPureDriveLite
BabolatAeroStorm
BabolatAeroproDrive
WilsonKͲBladeTeam
WilsonKͲBladeTeam
BabolatAeroproDrive
WOMEN
VictoriaAzarenka
ElenaDementieva
AmelieMauresmo
AnabelMedinaGarrigues
MelanieOudin
NadiaPetrova
AgnieszkaRadwanska
DinaraSafina
FrancescaSchiavone
SerenaWilliams
VenusWilliams
CarolineWozniacki
RACKET
IgorAndreev
BobBryan
MikeBryan
JuanCarlosFerrero
PhilippKohlschreiber
JurgenMelzer
DanielNestor
DudiSela
GillesSimon
RobinSoderling
FernandoVerdasco
NenadZimonjic
MEN
PLAYER
18
LuxilonAluPower
LuxilonAluPower
BabolatVSTeam
LuxilonAluPower
WilsonNatural
BabolatRevenge
BabolatProHurricane
LuxilonAluPower
BabolatRevenge
WilsonNatural
WilsonNatural
BabolatRevenge
LuxilonOriginal
LuxilonAluPowerRough/BabolatVSTouch
LuxilonAluPowerRough/BabolatVSTouch
LuxilonOriginal
LuxilonAluPower/WilsonNatural
IsospeedProfessional
WilsonNatural
LuxilonAluPower
HeadIntellitour
LuxilonAluPower
LuxilonOriginal
BabolatVSTeam
STRINGM's/X's
WIMBLEDON SELECTED 2009 PLAYER LOGS
62/61lbs
23/22kgs
24.5kgs
24.5kgs
52.5lbs
25.5/26.5kgs
23kgs
25/24kgs
21.5kgs
64lbs
68lbs
25kgs
25/23kgs
48/52lbs
47/51lbs
24.5/23.5kgs
23/22kgs
32kgs
52.5/50.5lbs
23kgs
20/19kgs
25kgs
23/21kgs
23/21.5kgs
2
18
19
7
2
10
4
35
6
55
46
9
6
32
29
24
13
15
7
9
10
31
21
13
TENSIONM's/X's STRUNG
Wimbledon 2009 Logs
Racquet Tech - October- 2009
Beat the Competition with ZyMax
®
Choose the ZyMax Badminton
String that Matches Your
Style of Game
Developed
for the
21st Century
ZyMax
62
ZyMax
70
The lightest string
ever made; 25% lighter
than standard .70 mm
strings. Optimum repulsion The strongest .70
mm string ever made. Has
with the crisp sound
been strung over 40 lbs.
players want to hear.
in special high tension
175x Cross Section
rackets. The best string for
Magnification
durability at all stringing
tensions.
ZyMax 62
ZyMax
67
Lowest tension
loss of any badminton
string. Exceptional tension
stability insures an excellent
combination of durability
and repulsion at all stringing
tensions.
Standard .70 mm String
Revolutionary ZyWeaVeTM core makes
ZyMax 62 25% lighter than standard
.70 mm badminton strings, maximizing
repulsion on smashes and control on
drop shots.
Revolutionary ZyWeaVe core allows
ZyMax 70 to be strung at 40.6 lbs in
Panda Power Ultra badminton frame.
2!#+%4342).'3
PO Box 549
Ashaway, Rhode Island USA 02804
ashawayusa.com
Available from:
”Excellent string for durability, feel
and control with no tension loss.
ZyMax 67 is perfect for my game.”
Ruilin Huang, (left) 2009 US Open
Ladies Doubles Champion playing
with ZyMax 67.
BENELUX
GERMANY
SWITZERLAND / AUSTRIA
FRANCE
www.distrisport.be +32 (0) 3 281 1314
www.victor-international.com +49 (0) 4121 450130
www.fb-victor.fr +33 (0) 1 4930 7770
Distri Sport International
SPAIN
Arisport
www.arisport.com +34 (0) 966 089829
Victor International GmbH
UK
Goode Sport
www.ashaway.co.uk +44 (0) 1707 321397
CFB Victor
ITALY
TetaSport snc
www.tetasport.com +39 (0) 2 26 14 84 99
Industry News
HEAD’s ‘Radical Messenger’ Application Lets Fans
to Serve Messages Using Andy Murray’s Arsenal of Shots
Video-based viral app continues company’s digital innovation
Using Facebook, the popular social networking site that allows family, friends and co-workers to connect
online, HEAD is launching “Radical Messenger”, a flash-based video messaging application that will allow
tennis fans to deliver digital messages to one another in an innovative way that no e-mail or IM possibly
can.
Andy Murray, the world’s No. 2 ranked tennis player, will be the messenger, smashing virtual tennis balls
containing written messages to computer screens around the world. Murray won’t simply hit “send” on
your behalf, but he’ll crank up his most outrageous trick shots, and hit the message-carry tennis balls
with his new HEAD YOUTEK™ Radical Pro.
The Radical series is powered by YOUTEK™, which combines superior technologies to give you the
individual benefits you need to match your playing style. At the core of the racquet is d3o®, a “smart
material” which dramatically changes its behavior under dynamic loading or impact.
“With my YOUTEK™ Radical Pro, I know that I am getting all the benefits of the original racquet with
new dynamic technology that responds to every shot to make,” said Murray. “I had fun on this shoot and
attempting shots with my racquet that you would never see me do on the tennis court. I hope people
like it.”
The app will be available to more than 200 million users on Facebook and on HEAD’s microsite,
radicalmessenger.head.com. It’s expected that many of the 80,000 digitally savvy fans who follow
Murray on Twitter will try Radical Messenger.
Radical Messenger brings to life the new YOUTEK™ Radical,
which Murray wields in his hands an innovation Western Union
telegram never could have foreseen. On their computers, users
can animate Murray to perform spectacular on-court moves
with their mouse-clicks and microphones. As message writers
type away, they see in the background of their screen Murray
patiently waiting to receive their “message ball”.
Radical Messenger truly is something to yell about. Screaming
into a web microphone is part of the fun. Once users type
in their message, they determine how “radical” the message
delivery will be. With their webcam and microphone on, the
message sender shouts, “C’mon, Andy!” as loud as possible.
An onscreen measurement of the yelling is displayed on screen.
The louder the user shouts, the more outrageous the shot by Murray. With the right encouragement,
Murray smashes the ball to the heavens and waits – until hurtles back to earth like a flaming meteor.
Radical Messenger continues HEAD’s journey into modern day digital communications. Earlier this year,
HEAD released a viral video of Novak Djokovic, depicting the No. 4 player in the world running down a
shot with more than enough time to leap into the stands, flirt with a young women, perform a juggling
routine, make a balloon animal, receive an oily massage from a fan – and smash a cross-court winner.
20
Racquet Tech - October- 2009
Industry News
Marc Valzer Will Play with Andy Murray
Tennis player from Valentigney, France, wins
grand prize of Golden HEAD Ball campaign
Marc Valzer, of Valentigney, France, couldn’t believe it when he found out that he actually won
the grand prize of the Golden HEAD Ball campaign “Win And Play With Andy Murray” – an
exclusive training session with World No. 2 Andy Murray and VIP tickets for the BARCLAYS
ATP World Tour Finals in London!
Valzer is currently studying physics and is an avid tennis player. He began playing the sport when he
was 10-years-old and now plays up to five hours of tennis every week. Valzer is also a member of the
ASCAP tennis club in Montbelliard and has participated in various tournaments, including the individual
championships in Franche Comte. He purchased the winning can of HEAD ATP tennis balls at the local
Intersport store.
The grand prize includes an exclusive training session with Andy Murray, roundtrip airfare for two to
London, stay at the player’s hotel and VIP tickets to the ATP World Tour Finals.
This was the second Golden HEAD Ball competition and about
20,000 tennis players from all over the world participated either by buying balls, by participating directly on the Internet
or by sending postcards. More than 1,000 of the participants
won prizes, such as HEAD rackets, bags, balls, footwear,
strings or and of course HEAD ATP tennis balls.
The Golden HEAD Tennis Balls hit store shelves last May and
feature a stylish metal can. HEAD is the official tennis ball of
the ATP, ATP Masters 1000 Series and BARCLAYS ATP World
Tour Finals in London. The HEAD ATP ball is the most used ball
on the ATP World Tour.
www.head.com
PTR Europe News
11th International Tennis Symposium
PTR Europe has announced the 11th International Tennis Symposium
will be held in Milan, Italy on November 14-15, 2009.
ICW - International Certification Workshop
Vorbereitungskurs auf die Internationale Zertifizierung der PTR
23. - 25. Oktober 2009 - TC Angertal
Ernst-Stinshoff-Strasse 50 - 40883 Ratingen
The PTR is running a International Certification Workshop in Ratingen,
Germany for preparation for PTR Certification tests.
21
Racquet Tech - October- 2009
Industry News
Weekend Brings Three ATP and WTA Event Titles for Prince Tour Team Players
Monfils, Peer and Montanes Win in Metz, Tashkent and Bucharest Respectively; Cap Dominant Weekend
The last weekend in September proved to be another successful one for the Prince Tour Team as it dominated three
of the events on the ATP and WTA calendar. Gael Monfils, Shahar Peer and Albert Montanes, all took home titles on
Sunday, winning in Metz, France; Tashkent, Uzbekistan and Bucharest, Romania respectively.
Gael Monfils, using his Prince EXO3 Rebel 95 racquet, showcased his masterful blend of punishing offense and
tactical defense to take out Phillip Kohlschreiber 7-6, 3-6, 6-2 in the Open de Moselle finals. Monfils, one of the first
players on tour to pick up a racquet from Prince’s EXO3 line (in fact, he made the switch from him former brand to
Prince after hitting only two tennis balls with the new EXO3 frame at the end of last year), shot up to a career high
ranking of #9 after doing so, reached the quarter-finals of Roland Garros and now captures his first title of the year.
With a cosmetic as colorful as Monfils himself, the EXO3 Rebel 95 not only suits his game-style, but has become one
of the most welcomed additions to the player frame market this year.
Prince WTA player, Shahar Peer showed that while the EXO3 Rebel 95 may be the right racquet for Monfils, the Prince
EXO3 Red 105 is best suited for her game. With her EXO3 Red in hand, Peer took home her second straight WTA
title – winning the Guangzhou Open in China last week and capturing the Tashkent title yesterday. The title is Peer’s
fifth for her career and second since making the switch to the EXO3 Red earlier this year.
Rounding out the weekend, Spaniard Albert Montanes edged Juan Monaco
7-6, 7-6 in the finals of the BCR Open in Bucharest to win his second title of
2009 (Estoril) and his third ATP title overall. The fifth seed, Montanes is one of
the players on tour to not only wield a Prince racquet (Prince Ozone Tour), but
rely on Prince apparel and footwear in competition as well.
visit www.princesports.com.
Prince Tour Team Member Maria Sharapova First WTA Tour Title Since Return From Surgery
Former World’s #1 Uses Prince O3 Speedport Black Racquet to Capture Toray Pan Pacific Open
After being sidelined by shoulder surgery for nine months, Maria Sharapova made her return to
tournament tennis in May with her new Prince O3 Speedport Black racquet in hand. Since then, she
has made a steady climb back up the rankings and has now captured her first tour title since the
comeback.
Sharapova reeled off five consecutive games to reach a 5-2 lead over current world #8 Jelena
Jankovic, before Jankovic retired the match due to injury, to win the Toray Pan Pacific Open in
Tokyo.
The win marks Sharapova’s 20th career title and first since Amelia Island in April of 2008. It was
Sharapova’s second final in her last three tournament appearances.
Sharapova is one of more than 20 ATP and WTA touring pros currently using the Prince O3
Speedport Black. Prince’s performance racquet line features racquets with the Company’s groundbreaking O-technology - easily identifiable by the large, visible ports along the
racquet frame.
visit: www.princesports.com
22
Racquet Tech - October- 2009
Industry News
Prince Premier LT String Shows Immediate Success and Popularity
Rated #1 Overall Synthetic Gut Ever Tested by US Stringers Association and Showing Greatest
Increase in Market Share of All Strings on the Market in 2009
Prince introduced its new Premier LT string at the beginning of this year. Upon its release, the United States
Racquet Stringers Association conducted a blind play test and ranked the new string as the #1 synthetic gut
string it has ever tested*. This is significant since the organization has conducted 125 synthetic gut blind play
tests spanning sixteen years!
It appears, from the most recent industry data**, the elite playability of Premier LT is translating into commercial success as well. With
a zero share in Q4 2008 (since it was not introduced until January 2009), the new string jumped to a 1.0% market share by end of Q2
2009, is already sitting at #22, and sold more than any other string introduced during the first half of the year - its first six months on
shelves.
“We are thrilled, but not entirely surprised, that players are responding so positively to this string,” says Dave Malinowski, Global
Business Director of Strings, Grips and Machines at Prince. “We took great care in coming to market with a string that embodies the
exceptional playing qualities of natural gut, but at a fraction of the cost – making it available to all players. Premier LT can be strung
up in all racquets, either full sets or in a hybrid format and will deliver exceptional feel, comfort and control for players whose skill levels
span from beginner to expert/tournament caliber.”
Premier LT is currently the recommended string for the Prince EXO3 Red 105, EXO3 Blue 110 and EXO3 Silver
118 racquets in and recommended as part of a hybrid in the EXO3 Ignite 95, EXO3 Ignite Team 95, EXO3 Rebel
95 and EXO3 Rebel Team 95– seven of the current nine frames in the EXO3 line.
visit: www.princesports.com
ENTDECKE
DIE WELT
DER
WE MAKE
A WORLD OF
DIFFERENCE
Die Int. Plattform für alle
Trainer und Coaches
die professionell
unterrichten
INFO: PTR European Headquarters
Leichtergasse 28 - 39012 MERAN
Fon: +39 0473 230097 - www.ptrtennis.de - [email protected]
Industry News
DUNLOP Scouting Tour 2009 als Premiere gelungen
Udo Riglewski und DUNLOP sichten junge Talente
In den fünf Städten Hamburg, Frankfurt, Köln, München und Berlin hat DUNLOP in Kooperation mit VertragsCoach Udo Riglewski die neu ins Leben gerufene DUNLOP Talentscouting Tour erfolgreich durchgeführt.
Die zwischen 6 und 12 Jahre alten Kinder und Jugendlichen durften jeweils an einem Nachmittag ihr Talent
unter Beweis stellen. Ziel der Veranstaltung ist es, außergewöhnliche Top-Talente zu finden, die später durch
DUNLOP in Form von Ausrüstung und finanziellen Zuschüssen gefördert werden. Teilnehmen konnte jeder,
Zulassungsbeschränkungen wie z.B. eine bestimmte Platzierung im Verband gab es keine. Allerdings mussten aufgrund der großen Nachfrage in Köln und Frankfurt die Teilnehmerzahl auf je 50 Spieler/innen beschränkt werden.
Udo Riglewski, der sich dem Bereich Talentsichtung und –förderung intensiv widmet, hat in Absprache mit
DUNLOP zwanzig Top-Talente ausgewählt, die zu einer weiteren Sichtung mit Riglewski im Frühjahr 2010
nach München eingeladen werden.
In 2010 ist eine neue DUNLOP Scouting Tour geplant. Neue
Sichtungs-Standorte und Termine werden ab Dort wird es für
Interessenten auch wieder die Möglichkeit geben, sich per OnlineFormular anzumelden.
www.teamdunlop.de
“Bow Brand International are pleased to report that, following the
success in finding an alternative Natural Gut Supplier, we have re-commenced
production of Natural Gut Tennis String.
The string will be available from January 6th
2010.
We also have a New and exciting range of Tennis
Hybrid Strings which will be launched at the same
time as our Natural Gut.”
www.bowbrand.co.uk
24
Racquet Tech - October- 2009
Industry News
World Junior Squash
Championships 2009 Chennai, India
Tecnifibre had great success in the championships with a
double win with the new Carboflex 130 rackets.
Two Egyptians, Mohammed El Shorbagy and Nour El Sherbini
won the 2009 World Junior Championship titles both using their
Carboflex 130 racquets.
The racquet has a balance of 355mm, head size 500cm² and
comes strung with X-One Biphase Red 1.18 string.
www.tecnifibre.com
Tecnifibre and 6th Sense Sign
International Partnership
Tecnifibre has just signed a new partnership with 6th Sense, the
tennis academy launched by Justine Henin and Carlos Rodriguez.
6th Sense has 2 academies. One in Belgium, the other in the
USA. Tecnifibre becomes the official partner along with Adidas.
Tecnifibre will equip all the coaches and be the official rackets,
strings and bags.
In addition, all the coaches and players will be using the Tecnifibre “Club” balls at both academies for training and practice.
Tecnifibre is interested is offering international contracts to players and academies interested in their products.
www.tecnifibre.com
www.6thsenseacademy.com
25
Racquet Tech - October- 2009
Technology
String Gauges
Are Thin Strings Softer or Stiffer?
By Rod Cross
Summary
Any given tennis string is normally available in several different diameters. The thinner versions might be expected to be more elastic
and to lose tension faster over time. Of 18 different string pairs tested, 8 of the thin versions were dynamically stiffer and 8 maintained
tension better than the corresponding thick versions. These effects were investigated by a controlled experiment where a thin string
was compared with a thick version of the same string made by placing two pieces of the thin string next to each other.
Introduction
Tennis strings are available in a range of diameters from about 1.20 mm (18 gauge) to about 1.40 mm (15 gauge). Manufacturers
have devised their own gauge system where 17 gauge is about 1.25 mm, 16 gauge is about 1.30 mm and 15L gauge is about 1.35
mm. The nominal diameters vary slightly from one manufacturer to the next. It is commonly assumed that thinner strings are softer or
more elastic, but recent tests undertaken by the author indicate that this is not necessarily the case.
All string models that were included in the USRSA 2000 String Survey results in two different gauge sizes were tested. This resulted
in a sample of 18 different pairs of 16 and 17 gauge strings. As demonstrated in the test, eight of the thinner strings were found to be
dynamically stiffer than the thicker versions.
The parameter of most relevance in a tennis string is the increase in elongation for a given increase in tension, starting at the tension
at which a racquet is normally strung. This parameter can be termed the dynamic stiffness, and it is this parameter that was observed
to be larger for 8 of the 18 thin strings (a string with a higher dynamic stiffness means that the string elongates less for a given tension
rise than does another). Neither the elongation nor the dynamic stiffness, at tensions lower than that at which the racquet is strung,
are of any consequence regarding the performance of tennis strings. (So don’t go by the stretchiness of a string during stringing. This
occurs in a tension range below the strung tension and is irrelevant. When you hit the ball, the tension rises rapidly above the strung
tension, and the string stretches by an amount that depends on the dynamic stiffness. Typically, a nylon string that is soft when you
string it is about twice as stiff when you hit the ball. The reason that it is twice as stiff is only partly because it is stretched faster. The
main reason is that the string does not stretch as easily at tensions above the normal strung tension, even if you stretch it slowly.)
The stiffness of the string plane in a racquet refers to the deflection in a direction perpendicular to the string plane when a force is
applied perpendicular to the string plane. For small deflections, this is independent of the dynamic stiffness of the strings and would
be the same for any type of string provided the string tension, string length and number of strings remained the same. For the larger
deflections encountered in practice, the string plane stiffness does depend on the dynamic stiffness since the string tension increases
significantly during an impact with a ball, typically by a factor of about two for a fast serve. The increase in tension is smaller for soft
strings such as natural gut, and larger for stiff strings such as aramid.
A graph of tension, T, vs elongation, x, for small and large diameter strings is shown in Fig. 1a below. For any given string, a graph of
T vs x will be a smooth curve, where the slope (i.e., steepness of the curve) at low T is typically about a factor of two smaller than at
high T, at least for nylon or polyester strings. Strings made from natural gut are more linear.
For purposes of illustration, the curve for a nylon or polyester string can be approximated by two linear segments, as in Fig. 1b,
showing the simplified graph of a thin and thick string (the normal shape of the curves is illustrated in figure 1a). If one assumes that
the material properties of the thin and thick strings are the same, and if the strings are the same length, then for any given elongation
x, T will be proportional to the cross-sectional area of the string. At any given tension, the extension of a thin string will therefore be
larger than that of a thick string. (Editor‘s Note: a tension vs elongation curve is different than a stress vs strain curve, though they
look the same. The former plots how tension changes with a given elongation in any given piece of string -- thick or thin. The stress
vs strain curve looks similar but it takes the size of the string into account -- factoring in the cross-sectional area and length of the
string. As a result, the stress vs strain curve will be the same for any string length or diameter of a given material. It measures the
property of the material of a standardized dimension. The tension vs elongation curve measures the behavior of string of a particular
dimension. Therefore, the same level of stress (tension divided by cross-sectional area, i.e., pounds per square inch) will occur at
different tensions for different gauges. Both gauges behave the same at the same stress; it‘s just that the thinner string achieves that
stress at a much lower tension. The two terms are incorrectly used interchangably in common discourse.)
27
Racquet Tech - October- 2009
Technology
In practice, racquets are strung at a tension of about 55 pounds, regardless of the string diameter. As a result, thick
strings can operate in a region where x and the dynamic stiffness k = dT/dx (i.e., change in tension divided by the
change in length) are both small, while thin strings can operate in a region where x and dT/dx are both large. In other
words, the dynamic stiffness of a thin string may be larger than that of a thicker string of the same material, depending
on the shape of the stress vs strain curve and the operating tension. (Note: both strings are acting the same in terms
of the stress they experience but that stress occurs at different tensions and elongations for each gauge in proportion
to their relative gauges.) In practice, the string tension can rise by a large factor during an impact, in which case an
average dynamic stiffness can be defined as DT/Dx, where DT is the increase in tension and Dx is the increase in
elongation.
Controlled Experiment
Most strings are constructed as composite materials with an inner core and an outer protective coating to
enhance durability. When the string diameter is varied, the relative dimensions of the core and the coating
may not remain fixed. Nevertheless, a string that is marketed under the same name would be expected to
have similar proportions of core to coating thickness, and the thinner gauge would normally be expected
to be more elastic and stretch further at a given static tension. Indeed, this was the case for most of the 18
string pairs tested. The exceptions may be due to a change in coating thickness or core composition, despite
each string pair having the same name. It might even be possible to manufacture a 17 gauge string simply by
stretching a 16 gauge version.
Since the precise composition and manufacturing techniques used to construct different gauge strings is
unknown, a controlled experiment was devised to investigate the effects of varying the string diameter. For
this purpose, the properties of a single 18 gauge nylon string (string A) were compared with a string (B) of
twice the cross-sectional area mounted in the test device as two lengths of string A in parallel. Strings A and
B were both tensioned, in separate experiments, to 62 pounds and then clamped at a fixed length (320 mm).
The tension in each string decreased with time due to stress relaxation. The tension in string A dropped by
9.2 lb to 52.8 lb after 1000 seconds. The tension in string B dropped by 11.9 lb to 50.1 lb after 1000 seconds.
This result is consistent with the common observation that thin strings often hold tension better than thick
strings, despite the fact that the stress in a thin string is larger. It is also consistent with the observation that
when string A was tensioned to 31 lb, the tension dropped by 6.1 lb to 24.9 lb after 1000 seconds. When
string B was tensioned to 62 lb, each “half” of the string was tensioned to 31 lb. If the tension in each half
drops by 6.1 lb after 1000 seconds, then the total tension in string B would drop by 12.2 lb, essentially as
observed.
The dynamic stiffness of strings A and B was measured immediately after the 1000 second delay, by
impacting ten times with a hammer as described in June 2000 Racquet Tech. In theory, one should be able
to determine the dynamic stiffness of a string simply by measuring its elongation curve under quasi-static
conditions using an Instron or similar materials testing device (these devises are like stringing machines
-- they pull relatively slowly and at a constant rate of elongation. That’s why the rate of pulling is always
specified in testing. These rates are typically 10 mm to 500 mm per minute.). In practice, this is not as
accurate or as relevant as an impact method since the elongation curve depends on the rate of stretch. For
example, if a string is stretched by an additional 1 mm and then clamped, the tension may increase by say 2
lb while the string is being stretched, but it immediately starts to decrease as soon as the string is clamped,
typically by about 0.4 lb in the first two seconds. This problem can be avoided if the string is stretched
sufficiently rapidly (a hammer impact stretches the string at a rate of about 1000 inches per minute).
For the impact tests, the impact duration was about 29 milliseconds for each string, and the impact energy
was 1.63 Joules per impact (equivalent to the energy on one string in a 120 mph serve). The increase in
28
Racquet Tech - October- 2009
Technology
tension during each impact was 37.8 lb on average for string A and 43.1 lb for string B. Calculations (see
note at right*) revealed that string A had a dynamic stiffness k = 196.6 lb/in averaged over 10 impacts, at an
average tension of 49.7 lb. For string B, k = 235.5 lb/in averaged over 10 impacts, at an average tension of
48.2 lb. An average tension is quoted since the tension decreased slightly following each impact. In this case,
the thinner string was softer, but not by the factor of two that one would expect if the stress vs strain curve
were linear. For string A, one can infer that the dynamic stiffness at a tension of about 48.4 lb is a factor of
1.7 larger than the dynamic stiffness at a tension of 24.2 lb. If it were a factor of two higher, then the dynamic
stiffness of strings A and B would have been the same.
To understand this, consider a simple spring. Suppose it stretches one inch when you pull it with a force of 25
lb. Suppose also that it stretches by 2 inches when you pull it with a force of 50 lb. Such a spring is said to be
linear since when you double the force you double the amount it stretches. Now suppose you put two such
springs in parallel, and pull with a force of 50 lb. Then there is a force of 25 lb acting on each spring, so they
each stretch by 1 inch. The two springs in parallel are twice as stiff as only spring since they stretch only one
inch at 50 lb, whereas one spring alone stretches by 2 inches at 50 lb. Similarly, two identical tennis strings
in parallel would be twice as stiff as one string alone, if the strings behaved as linear springs. In fact, it turned
out that strings A and B (i.e., two A strings in parallel) had about the same stiffness, which means that the
strings were not linear. For string A, one can infer that the dynamic stiffness at a tension of about 48.4 lb is a
factor of 1.7 larger than the dynamic stiffness at a tension of 24.2 lb. If it were a factor of two higher, then the
dynamic stiffness of strings A and B would have been the same. If the stiffness at 48.4 lb was the same as
the stiffness at 24.2 lb (i.e., the strings were linear) then string B would be twice as stiff as string A.
Conclusions
A surprising result of testing thin and thick versions of commercially available tennis strings is that thin strings
can be dynamically stiffer and they can maintain tension better than the corresponding thick versions. In
this paper it has been shown how this can arise. Two linear strings connected in parallel will be twice as
stiff as one. Tennis strings are nonlinear and have the property that the stiffness increases with tension.
Consequently, the stiffness of two parallel strings can be larger, smaller, or the same as that of a single string
depending on the stress vs strain curve and the operating tension. Similarly, the rate at which a string loses
tension is a nonlinear function of tension. The rate of tension loss increases with tension, but the loss rate
may not increase in proportion to the tension. As a result, two strings in parallel can lose tension at a faster
rate than a single string.
Next Issue December 2009
Gosen Flat String Technology
Japan Open New Tecnifibre Machine
Industry News
Tips
30
Racquet Tech - October- 2009
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