TW University finally tested the much ballyhooed Volkl Powerbridge 10 mid (thanks Prof!). For those who don't know, you can directly compare the "power potential" at 13 locations on the racquet face of two different racquets here:
http://twu.tennis-warehouse.com/learning_center/contours.php
The basic "Power Zone Comparison" page shows a graded rending of the actual power potential data in the form of "power zones". These are interesting to look at, as they give the best objective picture of what we might mean when we say a racquet has a large or small "sweet spot". The "sweet spot" in actuality being a single point (with no size), these "power zones" are all we have really, aside from subjective reports.
As cool as those are, it's actually more useful for direct comparison to go to the upper left hand corner of each racquet's window and click "location view". If you do this with the Volkl PB10mid in one window and Wilson's BLX 6.1 Tour in the other you can now look at the power potential at each location tested.
I'm interested in this comparison for several reasons:
1) Volkl claims their DNX material stiffens the head of the racquet, making it resist twisting of the racquet face in the event of an off-center impact with a ball. From their marketing, I would expect this type of intrinsic stability to translate as more power at those off-center impact locations. In terms of "power zones" I would expect the power zone of the PB10mid to be larger than a competing frame of a similar swingweight (swingweight being, by far, the largest determinant of power potential).
2) Many posters and reviewers on this site have opined that the PB10mid is more stable than its specs would indicate.
3) The BLX90, being the direct decendent of the hoary Wilson Pro Staff, is one of the most primitive racquets on the market. I don't mean that as a disparagement, but it's well-known that the BLX's forbear, the K90, was pretty much a 90 inch version of the Pro Staff, which is like 30 years old. One could argue that the K90 and BLX90 possess the characteristics of Wilson's vaunted Karophite black. But I think most astute posters here see this as a marketing sham. The K90 is, in all likelihood, constructed of the very same braided graphite and kevlar as was the Pro Staff. Of course, the BLX90 supposedly has some basalt in it. But basalt is a flexible material, and it's inclusion has resulted in the BLX being more flexible than the K90. Flexible racquets are usually considered less stable and less resistant to twisting and torque than a stiffer frame. For this reason I would actually expect the BLX90 to be less powerful and have a smaller "power zone" than the K90. So, in my eyes, the BLX 90 is a softer, mushier version of a 30 year old racquet.
So how does this updated dinosaur compare, in objective tests, to the ultra-modern Volkl PB10mid?
Looking at the Power Zone Comparison we can see the specs:
PB10mid: BLX90:
351.6g 351.3g
31.5cm 31.5cm
332 swingweight 329 swingweight
Twistweight: 11.19 Twistweight: 12.59
Flex:61 Flex:63
(Tennis Warehouse's product pages for these sticks show different flex ratings, but these numbers are directly form the frames that were tested by TW University.)
From these specs I would assume the numbers would be a wash. But, considering the rave reviews on the PB10mid and the vaunted qualities of the marvelously stabilizing DNX material, I would assume that the PB10 mid would be more powerful at off-center locations than the BLX90, especially since that frame is more or less an old man with a pair of fancy new shoes.
As you can see by the numbers below, the BLX90 is actually more powerful at all but two locations on the racquet face (exact center and tip). The difference at the center is negligable, but gives us a place from which to compare the drop-off from there as we move out and up. The BLX90 has more power, relative to the center location, then does the PB10mid. In other words its "powerzone" or "sweetzone" is larger.
However, if you compare either of these two mids with other player's sticks you'll find that they are, both of them, top of the class in terms of the sweet zone size. From this perspective they appear to be excellent choices for this headsize. But what surprises me is that the PB10 mid isn't even better, given the technological advantage it most surely possesses over the Pro Staff great-great-grandson.
One thing that jumped out at me when comparing the TW University specs is the difference in twistweights (11.19 vs. 12.59). If any of you recall, our old buddy Lama (aka Rush n' Crush) used to like to say that the DNX "nanotech" of the PB10mid gave the stablility of leadtape without the weight. This may, in fact, have a little truth. We know that twistweight has a big influence on the power potential at locations right and left of center. Since the PB10mid has a significantly lower twistweight than the BLX90 it could have had even poorer power off-center than it does if it didn't have the DNX. Even still, though, since the weight and swingweight of these sticks is pretty much the same, Rush's claim that the DNX gave the stability without the weight doesn't really hold up, since it has the weight too.
In other words, Wilson's 30 year old, PWS "technology" may just trump Volkl's DNX "technology".
http://twu.tennis-warehouse.com/learning_center/contours.php
The basic "Power Zone Comparison" page shows a graded rending of the actual power potential data in the form of "power zones". These are interesting to look at, as they give the best objective picture of what we might mean when we say a racquet has a large or small "sweet spot". The "sweet spot" in actuality being a single point (with no size), these "power zones" are all we have really, aside from subjective reports.
As cool as those are, it's actually more useful for direct comparison to go to the upper left hand corner of each racquet's window and click "location view". If you do this with the Volkl PB10mid in one window and Wilson's BLX 6.1 Tour in the other you can now look at the power potential at each location tested.
I'm interested in this comparison for several reasons:
1) Volkl claims their DNX material stiffens the head of the racquet, making it resist twisting of the racquet face in the event of an off-center impact with a ball. From their marketing, I would expect this type of intrinsic stability to translate as more power at those off-center impact locations. In terms of "power zones" I would expect the power zone of the PB10mid to be larger than a competing frame of a similar swingweight (swingweight being, by far, the largest determinant of power potential).
2) Many posters and reviewers on this site have opined that the PB10mid is more stable than its specs would indicate.
3) The BLX90, being the direct decendent of the hoary Wilson Pro Staff, is one of the most primitive racquets on the market. I don't mean that as a disparagement, but it's well-known that the BLX's forbear, the K90, was pretty much a 90 inch version of the Pro Staff, which is like 30 years old. One could argue that the K90 and BLX90 possess the characteristics of Wilson's vaunted Karophite black. But I think most astute posters here see this as a marketing sham. The K90 is, in all likelihood, constructed of the very same braided graphite and kevlar as was the Pro Staff. Of course, the BLX90 supposedly has some basalt in it. But basalt is a flexible material, and it's inclusion has resulted in the BLX being more flexible than the K90. Flexible racquets are usually considered less stable and less resistant to twisting and torque than a stiffer frame. For this reason I would actually expect the BLX90 to be less powerful and have a smaller "power zone" than the K90. So, in my eyes, the BLX 90 is a softer, mushier version of a 30 year old racquet.
So how does this updated dinosaur compare, in objective tests, to the ultra-modern Volkl PB10mid?
Looking at the Power Zone Comparison we can see the specs:
PB10mid: BLX90:
351.6g 351.3g
31.5cm 31.5cm
332 swingweight 329 swingweight
Twistweight: 11.19 Twistweight: 12.59
Flex:61 Flex:63
(Tennis Warehouse's product pages for these sticks show different flex ratings, but these numbers are directly form the frames that were tested by TW University.)
From these specs I would assume the numbers would be a wash. But, considering the rave reviews on the PB10mid and the vaunted qualities of the marvelously stabilizing DNX material, I would assume that the PB10 mid would be more powerful at off-center locations than the BLX90, especially since that frame is more or less an old man with a pair of fancy new shoes.
As you can see by the numbers below, the BLX90 is actually more powerful at all but two locations on the racquet face (exact center and tip). The difference at the center is negligable, but gives us a place from which to compare the drop-off from there as we move out and up. The BLX90 has more power, relative to the center location, then does the PB10mid. In other words its "powerzone" or "sweetzone" is larger.
However, if you compare either of these two mids with other player's sticks you'll find that they are, both of them, top of the class in terms of the sweet zone size. From this perspective they appear to be excellent choices for this headsize. But what surprises me is that the PB10 mid isn't even better, given the technological advantage it most surely possesses over the Pro Staff great-great-grandson.
One thing that jumped out at me when comparing the TW University specs is the difference in twistweights (11.19 vs. 12.59). If any of you recall, our old buddy Lama (aka Rush n' Crush) used to like to say that the DNX "nanotech" of the PB10mid gave the stablility of leadtape without the weight. This may, in fact, have a little truth. We know that twistweight has a big influence on the power potential at locations right and left of center. Since the PB10mid has a significantly lower twistweight than the BLX90 it could have had even poorer power off-center than it does if it didn't have the DNX. Even still, though, since the weight and swingweight of these sticks is pretty much the same, Rush's claim that the DNX gave the stability without the weight doesn't really hold up, since it has the weight too.
In other words, Wilson's 30 year old, PWS "technology" may just trump Volkl's DNX "technology".
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