Category Archives: Accuracy
Moving between several reviews to compare racquets is tiresome, for sure, and inefficient!
We don’t want you to be tired or inefficient, so we include our Three Racquet Comp Data for the new Head Gravity 2023 models!
A word about “dwell time”. To get a more accurate view of the racquet we have elimiiated the player from the “slow” dwell time. This allows us to see excatly what happens when the ball is “dropped” on the string bed without any external force (your swing)!
We have made several posts regarding SBS, which is “String Bed Stiffness” and this is another one!
If you read this post we really need your comment(s), really!
String bed stiffness is the “feeling” when the ball hits the string on a tennis racquet. Due to the various string materials there will be “soft” and “hard” feelings. But wait, there’s more!
The string bed is made up of several strings, some longer called the Main string (M)and some shorter called the Cross string(X). Using “reference” tension each of the sets of string will be pulled at the same machine setting! It the machine is set at 50 pounds the tension head will stop pulling when it feels 50 pounds of resistance, regardless of what he tension inside the racquet head may be.
Let’s say you come into the world headquarters and we ask you what SBS you would like to have? Would you know? Probably not and not many would! We have grown up using the term “reference tension”, not SBS.
Reference tension is “number” you would ask your racquet technician to set the stringing machine tension system on. That number will probably be between 30 and 60 pounds (≈13 to 26 Kilo).
So, depending on many other variables, such as string material, string pattern, stringing machine, stringer technique, etc., you can end up with may different versions of the same “reference tension”.
A better way, and one we have been using for over thirty (30) years, is SBS but not everyone has bought into the concept, even though a qualified racquet technician will have a way to measure SBS! Maybe because it is too much trouble to figure out what your desired SBS from machine X would be from machine A! It is not!
There have been several really good SBS data collection devices but they have been difficult to use, and pricy! Not to mention gigantic!
Would you purchase a SBS data collection device?
How much would you pay for such a device?
Would you prefer a mechanical device or an electronic device?
The device must be portable, that is easily carried in a racquet bag or backpack
Yes or It doesn’t matter
It must be easy to use.
If you use an SBS device would you use a racquet technician that did not know what SBS is or how to measure it?
Thank you for adding your comments to this discussion! It is important stuff!
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.
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.
This years Head Prestige Pro is last years Prestige MP. This name change was made to synchronize all the 18×20 string patterns as the “Pro” model…I think!
So, what’s in a name? A thin beam, heavy (sort of), 18×20 pattern, players racquet, that’s what! The Prestige Pro also includes the new Auxetic material and construction for a refined feel.
For some reason Head Prestige racquets have been called “stiff” by some and this is certainly not the case and never has been. This racquet is not stiff! As with any racquet the string selection can have a huge effect on “stiffness” so take a look at the effective stiffness!
I believe this is going to be a “control freaks” racquet! This racquet could also be a baseliners dream come true. The weight will drive through the ball and the swing weight will allow for some last nano-second stroke adjustments.
Take at look at the data below then go to the Prestige 2021 Comparative Data post to see all the models in one place.
|Racquet Model||Head Prestige Pro 2021|
|Reference Tension||52 lbs - 23.6 kg|
|String||Head Reflex MLT 17|
|Machine Used||True Tension Professional|
|Racquet Flex, RDC||58 - After stringing|
|Racquet Flex, FlexFour||36.0|
|Racquet - In Plane Stiffness||326.1 lbs/Inch|
|Head Area, cm2||627.4|
|Head Area, Sq. Inch||97.2|
|Number of Main Strings||18|
|Number of Cross Strings||20|
|Main String Grid||7.56|
|Cross String Grid||10.24|
|Density (% of head filled with string)||.791|
|Average Cross String Space||.513|
|Average Main String Space||.417
|Dynamic Tension, Kp, ERT||35|
|Dynamic Tension, Lbs/in||195.76|
|First Moment, Nm||.832|
|Swing Weight, Kg/cm2||318|
|Swing Weight, Ounces||11.22|
|Swing Weight Calculated||345.8|
|Head Weight, %||46.4%|
|Center of Percussion||20.7|
|Dwell Time, ms||8.74|
|Efective Stiffness - lbs||27.7|
Jumping back and forth between reviews and data is not fun nor is it efficient so we have been posting comparative data. Now all the important stuff is in one place.
All of the data is based on a “play ready” racquet. That means an overgrip and vibration damper, and unless otherwise noted…string!
As you are looking at the data try to determine which numbers mean the most to you and how you could use them. For example, the Pro has an overall weight of 342 with a swing weight 318. How does that compare to the MP?
Keep in mind that weight and swing weight can increased but not easily decreased. No, making the racquet more “head light” statically does not reduce the swing weight as recorded on testing devices that grab the racquet 10cm from the end! That is why static balance (CG) should not be used as a performance metric.
Click here to see the data!