Category Archives: Kinesiology
Bolt 100 v2
Bolt tennis racquets have been around for a few years and we have reported on them in the past, however, the new V2 of the Bolt racquet lineup is very impressive!
If you are not at all familiar with the Bolt technology it is the “Zip Strip” that makes them unique. The “Zip Strip” is a carbon fiber component that looks like a miniature tennis racquet cross-section that fits into the sides and top that actually do the “bending” during string and racquet impact!
This “bending” can mitigate harshness associated with very stiff strings or a very stiff racquet!
Before we look at the specifications you can visit the Bolt site for more information.
| Bolt 98L, V2 | |
|---|---|
| Manufacturer | Bolt |
| Racquet Model | Bolt 100, v2 |
| Reference Tension | 57 lbs - 25.9 k |
| String: Main/Cross | Head Reflex |
| Machine Used | True Tension Pro |
| ASPS, RDC | 56 |
| ASPS, FlexFour | 64.5 |
| Racquet Flex, RDC | 64 - After stringing |
| Racquet Flex, FlexFour | 46 |
| Weight, Grams | 313 |
| Weight, Ounces | 11.06 |
| Balance, mm | 337 |
| Balance, Inch | 13.27 |
| Length, Cm | 68.5 |
| Length, Inch | 26.98 |
| Head Width | 9.589 |
| Head Length | 13.13 |
| Head Area, cm2 | 665.1 |
| Head Area, Sq. Inch | 103.1 |
| Beam Width, mm, Shaft, Center, Tip | 24.5, 24.5, 23.8 |
| In Plane Stiffness, Pounds/In | 454 Lbs/In. |
| In Plane Stiffness, Kg/cm | 178.7 Kg/cm |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio Cross/Mains | .642 |
| Main String Grid | 7.37 |
| Cross String Grid | 9.62 |
| Density (% of head filled with string) | .688 |
| Average Cross String Space | .506 |
| Average Main String Space | .461 |
| Dynamic Tension, Kp, ERT | 36 |
| Dynamic Tension, Lbs/in | 201.35 |
| First Moment, Nm | .822 |
| Polar Moment | 350 |
| Torsional Stability | 19 |
| Swing Weight, Kg/cm2 | 331 |
| Swing Weight, Ounces | 11.68 |
| Swing Weight Calculated | 356.6 |
| Power, RDC | 48 |
| Control, RDC | 53 |
| Manueverability, RDC | 66 |
| Power, Calculated | 2183.7 |
| Head Points | 1.42 (negative = head heavy) |
| Head Weight, % | 49.3% |
| Center of Percussion | 21.4 |
| Dwell Time, ms, No Swing | 8.50 |
| Effective Stiffness - lbs | 29.9 |
| K, Lb/In (SBS) RDC | 179.49 |
| Recoil Weight | 157.0 |
| Twist Weight | 234.11 |
| End Weight | 118.7 |
| Tip Weight | 196.1 |
| Total Weight | 314.8 |
| 9 O'Clock | 103.0 |
| 3 O'Clock | 98.9 |
| Butt Cap | 110.3 |
| Total Weight | 312.2 |
Friction v Tension…what wins?
We all know what friction is. It keeps our cars from sliding around, it keeps us from slipping and in general makes movement possible!
Friction also plays an important part in the string bed of your tennis racquet. Friction between the strings and the ball create friction which in turn creates rotation.
What are, however, some of the downsides of friction in the string bed during, and after, the stringing process?
Friction v Tension
For more detailed information and a graph showing the forces involved go to our membership site, GASP.network, but in the meantime this image will show the frictional forces at work!
This machine tension head will pull the string (blue) in the direction of the center of the racquet support structure instead of directly out the middle of the grommet.
It is obvious that this will create considerable friction and result in lower tension inside the grommet than outside the grommet.
Head Graphene 360+ Radical S v21
From our perspective the Radical S should be one of the most used of the Radical Series!
Head Graphene 360+ Radical S
Why? The 102 square inch head size is optimum for players looking for additional power,( and who isn’t) in a legitimate players racquet. We say “legitimate” because this racquet can be turned into any thing you want, now or in the future!
As you will see in the specifications this is not a really stiff racquet so it will be easy for many players to customize the string bed to suit current playing style with an eye toward becoming a more aggressive player, or not!
The Radical S continues with the “control pattern” and “sound grommets”. We are not totally certain what the “sound grommets” do but sound is frequency and frequency can be felt so maybe the grommets are damping out some of the higher frequencies?
Anyway, this Radical S model is a great step into the “performance” racquet arena with plenty of room to grow!
| Head Graphene 360+ Radical S v21 | |
|---|---|
| Manufacturer | Head |
| Racquet Model | Head Graphene 360+ Radical S v21 |
| Reference Tension | 55 lbs - 24.9 k |
| String: Main/Cross | Victrex 7718 |
| Machine Used | TT Professional |
| ASPS, RDC | 55 |
| ASPS, FlexFour | 61.5 |
| Racquet Flex, RDC | 61 - After stringing |
| Racquet Flex, FlexFour | 50 |
| Weight, Grams | 296 |
| Weight, Ounces | 10.44 |
| Balance, mm | 333 |
| Balance, Inch | 13.11 |
| Length, Cm | 68.5 |
| Length, Inch | 26.968 |
| Head Width | 9.860 |
| Head Length | 13.09 |
| Head Area, cm2 | 653.9 |
| Head Area, Sq. Inch | 101.3 |
| Beam Width, mm, Shaft, Center, Tip | 22, 25, 23 |
| In Plane Stiffness, Pounds/In | 370.4 Lbs/In |
| In Plane Stiffness, Kg/cm | 66.2 Kg/cm |
| Number of Main Strings | 16 |
| Number of Cross Strings | 19 |
| Ratio Cross/Mains | .634 |
| Main String Grid | 7.30 |
| Cross String Grid | 9.75 |
| Density (% of head filled with string) | .703 |
| Average Cross String Space | .513 |
| Average Main String Space | .449 |
| Dynamic Tension, Kp, ERT | 35 |
| Dynamic Tension, Lbs/in | 195.8 |
| First Moment, Nm | .764 |
| Polar Moment | 320 |
| Torsional Stability | 17 |
| Swing Weight, Kg/cm2 | 303 |
| Swing Weight, Ounces | 10.69 |
| Swing Weight Calculated | 328 |
| Power, RDC | 42 |
| Control, RDC | 60 |
| Manueverability, RDC | 85 |
| Power, Calculated | 1873.1 |
| Head Points | 2.99 (negative = head heavy) |
| Head Weight, % | 48.6% |
| Center of Percussion | 21.2 |
| Dwell Time, ms, No Swing | 8.58 |
| Effective Stiffness - lbs | 28.9 |
| K, Lb/In (SBS) RDC | 176.28 |
| Recoil Weight | 144.50 |
| Twist Weight | 214.65 |
| End Weight | 113.1 |
| Tip Weight | 183.4 |
| Total Weight | 296.5 |
| 9 O'Clock | 92.1 |
| 3 O'Clock | 91.8 |
| Butt Cap | 112.2 |
| Total Weight | 296.1 |
Head Graphene 360+ Radical Series Comparative Data
Click Here to See Radical Series Comparison Data
Radical MP v21
A Close Look at Orange
The new, for 2021, Head Graphene 360+ Radical series is a radical step into colors that have always been the “mark” of the Radical Series but now it has gone even further into radicalism!
We think that is a good thing! Why mess around with just a little orange when you can go all out!
It is impossible to see the vibrancy of this orange without holding it in your hand! We invite to to hold one in your hand and even hit with it!
The Radical MP has been the most popular model over the years. This model has all the attributes of the Pro without the added weight, (which can be added later if needed)!
The thin beam carries over to the MP and Pro while the S has a slightly wider beam.
The S model fits the very necessary range of 102 square inch racquets because Head has, correctly, reduced the number of head sizes per model. The Speed series has the 100 square inch head size very well covered.
You will see all the specifications on each individual review that will be posted shortly.
Head Graphene 360+ Radical Pro
Head Graphene 360+ Radical S
Racquet Quest, LLC
