Category Archives: String

All string information

What’s The Difference?

As tennis players, you must constantly ask “what’s the difference” when it comes to tennis racquets and string! Well, as racquet technicians we ask the same questions!

This post is intended to showcase the differences of string in testing, not playing, however, some of the data may be noticeable to the player in certain situations.

What this graph shows us, in addition to our trying to save a tree by printing on the back of previously used paper, is that each of these stings will provide almost the same performance. This is indicated by the curve and how closely related the strings are.

Tensile Strength Comparison

The differences you do see here can be attributed to the gauge, or diameter, of the string, with the largest diameter (Tour Bite) having the highest tensile strength.  Down in the “hitting” displacement range (way below the 39.9mm!), there is very little difference.

The tensile strength can be a factor as the string begins to “notch” or otherwise come apart.  Each of the strings in this graph is monofilament so notching would be the failure mode in a racquet.

 

Head Boom MP 2022

Head has introduced a brand new racquet! So, you say, what’s new about that they do it every year! Yes, but this is a different racquet!

This is the Boom!
In all the years we have been dealing with Head it has become clear that they are not averse to making new things…instead of drastically changing old things.

The Boom is available in a Pro version and a MP version, with the Pro version being a little heavier.

So the Boom, which will be available in January of 2022, (pre order now!) is a new racquet and it is not shy about it!

The head shape is a little different, the shaft is a little different, and the Auxetic material and construction is a little different and all these “littles” add up to a totally different hitting experience!

The shaft transitions from a common box to a trapezoid as it junctions with the yoke (which is the Auxetic area, don’t forget)

The 24mm beam (actually 22, 24.4, 23.3) is a solid choice for advancing players offering just the right amount of stiffness for a little extra “punch”.

We believe the recoil weight could be higher and that is easily accomplished when wanted.  

 

The MP and Pro demo’s are ready for your evaluation! These are very popular demo’s!
ManufacturerHead
Racquet ModelHead Boom MP 2022
Reference Tension55 lbs - 24.9 kg
String
Tecnifibre BiPhase 124
Machine UsedTrue Tension Professional
Static
ASPS, RDC55.0
ASPS, FlexFour64.0
Racquet Flex, RDC62 - After stringing
Racquet Flex, FlexFour42.0
Racquet - In Plane Stiffness344.8 lbs/Inch
Weight, Grams320
Weight, Ounces11.29

Balance, mm327
Balance, Inch12.87
Length, Cm68.6
Length, Inch27.008
Head Width9.83
Head Length12.84
Head Area, cm2639.4
Head Area, Sq. Inch99.1
Number of Main Strings16
Number of Cross Strings19
Ratio Cross/Mains.645
Main String Grid7.61
Cross String Grid10.68
Density (% of head filled with string).774
Average Cross String Space.475
Average Main String Space.562
Dynamic
Dynamic Tension, Kp, ERT35
Dynamic Tension, Lbs/in195.7
First Moment, Nm.807
Polar Moment325
Torsional Stability13
Swing Weight, Kg/cm2312
Swing Weight, Ounces11.01
Swing Weight Calculated342.2
Power, RDC45
Control, RDC56
Manueverability, RDC79
Power, Calculated 1936.2
Head Points5.04
Head Weight, %47.7%
Center of Percussion20.80
Dwell Time, ms8.58
Efective Stiffness - lbs29.1
K, Lb/In176.26
Recoil Weight149.42
Twist Weight231.14
End Weight 127.9
Tip Weight 191.8
9 O'Clock96.5
3 O'Clock96.1
Butt Cap126.8

 

What Can Pictures Tell Us About String?

It is said that “a picture is worth a thousand words,” which may be true as long as the picture tells a story.

This story is about natural gut string, and the pictures will show what we can achieve, informationally, with our testing equipment. The two (2) strings are Babolat VS Touch 17 and Luxilon Natural Gut 125.

Both are awesome products, and we use a lot of both of them, but for different reasons, we may be able to understand by the pictures!

Our Questron software scales the images to suit the data so the graphs will not be the same size.

Babolat VS Touch 17

Our testing loads the string from 0 pounds force to 50 pounds and back to zero then up to 50 pounds three (3) times.  This is the “stress/strain” curve.  Fifty (50) pounds is arbitrary and because we are using the same methodology for all string materials it is a good number.  The closer these lines are together the better.

The farther it takes to reach 50 pounds the “higher elongation” the string is.  In this case it is about 44mm.

The important property of this string is the linearity!  That is the “straightness” of the line from beginning to end.  This indicates predictability, stability, and consistency.

This picture tells us the tensile strength and the knot strength.  In this case the knot strength is 52.3 pounds and takes a stretch to very close to 60mm before failure.

Luxilon Natural Gut 125

What is, probably, the first thing you notice about this “picture”? Could it be the squiggly lines? What could be causing this?

We believe it is the “break-in period” players associate with Luxilon gut! We have heard it from the players but have not been able to “see” it! It could be the bonding agents realigning as the load is applied.

You will notice a couple of things: the similarity of the “stress/strain” curve and the displacement to “knot strength” of the two strings. This string will feel a little less “soft” than the Babolat VS Touch 17. The linearity is quite good up to failure.

So, based on these pictures, could you make a recommendation? If so, let us hear them!

And The Winner Is…

If you know anything about Tecnifibre yo know they make some of the best multifilament strings in the business!

 

The winner is Tecnifibre MultiFeel 17!

This string, MultiFeel, is a very “soft” polyurethane bonded construction that offers playability and a good value!

Tecnifibre MultiFeel !7 Gauge

This graph shows the high elongation and nice elasticity of this string.  The fairly linear slope up to failure would indicate some consistency of shot all the way up to breakage!

The knot strength is pretty good for a thin multifilament and we can say from experience that the know is going to be fine when property “tightened” and large enough to not slip bak into the grommet barrel.

If you are considering a multifilament this would be a good one to try!

And the winner is…Head FXP 17

 

Head FXP is a string that seems to be largely overlooked and I am surprised after seeing the results of the installation and testing!

String NameCategoryGaugeUltimate Tensile Strength/LbsKnot Strength/LbsCountry of Origin
Head FXPMultifilament - Nylon17165.993.4Japan

Both the tensile strength and knot strength are exceptional and the graph shows that this string is very “elastic” which is a good thing for tennis racquet string but sometimes just not considered.

Head FXP 17

The area under the solid red lines is considered a stress-strain curve and indicates the “elasticity” of string by how close the lines fit from 0 to 50 three (3) times.  A perfectly elastic material would be one line even though it went through three (3) cycles.  What you see here is quite good and one of the reasons it is the winner!